The document discusses various β-lactam antibiotics including penicillins and cephalosporins. It describes the chemical structure of penicillins including the β-lactam ring. It discusses the classes of penicillins, their history, mechanisms of action, degradation pathways, structure-activity relationships, resistance issues and classification. Specific penicillins discussed include benzylpenicillin, phenoxymethyl penicillin, methicillin, ampicillin, amoxicillin, oxacillin, cloxacillin and dicloxacillin.
This document discusses beta-lactamase inhibitors which are used to combat bacteria that have developed resistance to beta-lactam antibiotics like penicillins and cephalosporins. It explains that beta-lactamase enzymes produced by bacteria inactivate beta-lactam antibiotics by breaking the beta-lactam ring. The three main inhibitors discussed are clavulanic acid, sulbactam, and tazobactam, which are commonly used in combination with other antibiotics. Clavulanic acid is well-absorbed orally and re-establishes activity against common resistant bacteria. Sulbactam has less potency than clavulanic acid and is preferably given parenter
This document discusses anti-protozoal drugs used to treat protozoan infections. It describes how protozoan infections are caused by organisms formerly classified as protozoa and are contracted through insect vectors or contact with infected substances. It then outlines several classes of pharmaceuticals used to treat protozoan diseases, including nitroimidazole derivatives like metronidazole, diloxanide, iodoquinol, pentamidine, atovaquone, and eflornithine. It provides details on the structures and mechanisms of action of these various antiprotozoal agents.
Chloramphenicol is a broad-spectrum antibiotic produced by Streptomyces venezuelae bacteria. It works by inhibiting bacterial protein synthesis at the ribosome. It has activity against both gram-positive and gram-negative bacteria as well as some protozoa. Chloramphenicol can cause serious and potentially fatal bone marrow suppression. As a result, it is now rarely used except for certain severe infections like meningitis and anaerobic infections. It is also used topically for eye and ear infections.
This document discusses the synthesis, mechanisms, properties, and uses of several antifungal drugs: Metronidazole, Ketoconazole, Terconazole, and Miconazole. It provides details on the synthesis routes for each drug involving reactions of intermediates. The mechanisms of action involve inhibiting enzymes necessary for fungal cell wall synthesis or metabolism, which damages DNA and leads to cell death. The properties described include melting points, solubility, and physical forms. All four drugs are used as broad-spectrum antifungal agents to treat various fungal infections.
Tetracyclines slide contains full information about uses, adverse effect, marketed preparation, precaution, route of drug administration, antimicrobial spectrum, mechanism of action, pharmacokineticks and pharmacodynamics of tetracyclines. This slide is very helpful for pharmacy and pharmacology student for the study about tetracyclines.
This document discusses beta-lactamase inhibitors which are used to combat bacteria that have developed resistance to beta-lactam antibiotics like penicillins and cephalosporins. It explains that beta-lactamase enzymes produced by bacteria inactivate beta-lactam antibiotics by breaking the beta-lactam ring. The three main inhibitors discussed are clavulanic acid, sulbactam, and tazobactam, which are commonly used in combination with other antibiotics. Clavulanic acid is well-absorbed orally and re-establishes activity against common resistant bacteria. Sulbactam has less potency than clavulanic acid and is preferably given parenter
This document discusses anti-protozoal drugs used to treat protozoan infections. It describes how protozoan infections are caused by organisms formerly classified as protozoa and are contracted through insect vectors or contact with infected substances. It then outlines several classes of pharmaceuticals used to treat protozoan diseases, including nitroimidazole derivatives like metronidazole, diloxanide, iodoquinol, pentamidine, atovaquone, and eflornithine. It provides details on the structures and mechanisms of action of these various antiprotozoal agents.
Chloramphenicol is a broad-spectrum antibiotic produced by Streptomyces venezuelae bacteria. It works by inhibiting bacterial protein synthesis at the ribosome. It has activity against both gram-positive and gram-negative bacteria as well as some protozoa. Chloramphenicol can cause serious and potentially fatal bone marrow suppression. As a result, it is now rarely used except for certain severe infections like meningitis and anaerobic infections. It is also used topically for eye and ear infections.
This document discusses the synthesis, mechanisms, properties, and uses of several antifungal drugs: Metronidazole, Ketoconazole, Terconazole, and Miconazole. It provides details on the synthesis routes for each drug involving reactions of intermediates. The mechanisms of action involve inhibiting enzymes necessary for fungal cell wall synthesis or metabolism, which damages DNA and leads to cell death. The properties described include melting points, solubility, and physical forms. All four drugs are used as broad-spectrum antifungal agents to treat various fungal infections.
Tetracyclines slide contains full information about uses, adverse effect, marketed preparation, precaution, route of drug administration, antimicrobial spectrum, mechanism of action, pharmacokineticks and pharmacodynamics of tetracyclines. This slide is very helpful for pharmacy and pharmacology student for the study about tetracyclines.
Anti Malarial Drugs of medicinal chemistryPranjal Saxena
This slide contain information about Anti Malarial Drugs and their description with the synthesis of Chloroquine and pamaquine
SAR of quinolines
Miscellaneous agents of anti Malarial
These are antibiotics having a macrocyclic
lactone ring with attached sugars. Erythromycin
is the first member discovered in the 1950s,
Roxithromycin, Clarithromycin and Azithromycin
are the later additions. Antimicrobial spectrum is narrow,
includes mostly gram-positive and a few gramnegative
bacteria, and overlaps considerably with
that of penicillin G. Erythromycin is highly active
against Str. pyogenes and Str. pneumoniae, N.
gonorrhoeae, Clostridia, C. diphtheriae and
Listeria, but penicillin-resistant Staphylococci
and Streptococci are now resistant to erythromycin
also.
All cocci readily develop resistance
to erythromycin, mostly by acquiring the
capacity to pump it out. Resistant Enterobacteriaceae
have been found to produce an erythromycin
esterase. Alteration in the ribosomal binding
site for erythromycin by a plasmid encoded
methylase enzyme is an important mechanism of
resistance in gram-positive bacteria. All the above
types of resistance are plasmid mediated. Change
in the 50S ribosome by chromosomal mutation
reducing macrolide binding a
Aminoglycosides(medicinal chemistry by p.ravisankar)Dr. Ravi Sankar
Aminoglycosides,Aminocyclitols,Source,Structures of streptomycin,Dihydrostreptomycin,A mention of other aminoglycoside antibiotics,Acid hydrolysis,Mechanism of action,SAR,Dihydrostreptomycin and its importance,therapeutic uses, toxicity.
Penicillins by Dr. Panchumarthy Ravisankar M.Pharm., Ph.D.Dr. Ravi Sankar
The document discusses penicillins, including their:
1) Historical background of discovery by Alexander Fleming in 1928 from Penicillium notatum.
2) Classification based on structure, spectrum, source and pharmacological activity, with penicillins classified under the beta-lactam class.
3) Structures of different penicillins such as penicillin G, penicillin V, methicillin, and isoxazolyl penicillins.
This document discusses beta-lactamase inhibitors such as clavulanic acid, sulbactam, and tazobactam, which inhibit beta-lactamase enzymes produced by bacteria and restore the effectiveness of beta-lactam antibiotics. Clavulanic acid inhibits a wide range of beta-lactamases. Sulbactam and tazobactam are similar to clavulanic acid but less potent. These inhibitors are often combined with antibiotics like amoxicillin and piperacillin to treat infections caused by beta-lactamase producing bacteria. Carbapenems and monobactams were also developed to be resistant to beta-l
Quinolones are synthetic antibacterial agents derived from nalidixic acid. Modern fluoroquinolones are classified into generations based on potency and spectrum of activity, with later generations having broader coverage. They work by inhibiting bacterial DNA gyrase and topoisomerase IV, preventing DNA replication. Common quinolones include norfloxacin for urinary tract infections, ciprofloxacin with activity against Pseudomonas, and sparfloxacin active against streptococci and anaerobes.
Urinary tract infections are mainly caused by bacteria like E. coli and Staphylococcus. Common symptoms include burning during urination and red or pink colored urine. Quinolones are a class of antibiotics that are highly effective against many infectious diseases, including those caused by bacteria in the urinary tract. Quinolones work by inhibiting the bacterial DNA gyrase enzyme, which is responsible for compacting DNA and allowing replication. Some examples of quinolones used to treat UTIs are ciprofloxacin, norfloxacin, and ofloxacin. Other classes of antibiotics that can be used to treat UTIs include nitrofurans, sulfa drugs, and methenamine.
This document provides an overview of antibiotics, including their historical background, classification, mechanisms of action, and examples. It focuses on penicillins and their discovery by Alexander Fleming in 1928. Penicillins are beta-lactam antibiotics that work by inhibiting bacterial cell wall synthesis. They have broad applications for treating bacterial infections. The document also discusses cephalosporins, another class of beta-lactam antibiotics derived from the fungus Cephalosporium.
Cephalosporins are β-lactam antibiotics isolated from the fungus Cephalosporium. Interest in these fungi began in 1945 with the discovery that their cultures inhibited both gram-positive and gram-negative bacteria. The first isolated compounds were cephalosporin C, cephalosporin N, and cephalosporin P. Cephalosporins are classified based on their structure, spectrum of activity, and resistance to penicillinase. They work by inhibiting transpeptidase and preventing cell wall synthesis in bacteria. Modifications to the structure can alter their properties and spectrum. β-lactamase inhibitors are used to overcome resistance from the β-lactamase enzyme.
Macrolides are a class of antibiotics derived from Saccharopolyspora erythraea (originally called Streptomyces erythreus), a type of soil-borne bacteria.
The document summarizes key information about aminoglycoside antibiotics. It discusses their discovery, examples currently used, and properties like poor absorption and administration by injection. Mechanisms of action involve binding to bacterial ribosomes to inhibit protein synthesis. Resistance can develop through enzymatic modification of the antibiotics. The structure and functional groups of the different rings that make up aminoglycosides influence their activity, spectrum, and susceptibility to resistance mechanisms.
This document discusses tetracycline antibiotics. It describes their structure, mechanism of action, derivatives, and spectrum of activity. Tetracyclines are broad-spectrum antibiotics obtained from Streptomyces bacteria. They work by inhibiting bacterial protein synthesis by binding to the 30S ribosomal subunit. There are several medically used tetracycline compounds that differ slightly in their chemical structures. Resistance can occur through efflux pumps, ribosomal protection, or enzymatic oxidation. The tetracyclines demonstrate the broadest antibacterial spectrum of any antibiotic class.
Chloramphenicol is a broad-spectrum antibiotic that was initially obtained from Streptomyces bacteria but is now produced synthetically. It inhibits bacterial protein synthesis by binding reversibly to the 50S ribosomal subunit. It is primarily bacteriostatic but can be bactericidal at high concentrations. Common adverse effects include bone marrow suppression, hypersensitivity reactions, and gray baby syndrome in neonates. It is used to treat typhoid fever, meningococcal infections, and anaerobic infections when other antibiotics cannot be used.
This document discusses beta lactamase inhibitors and monobactams. It describes clavulanic acid, sulbactam, and tazobactam, which are beta lactamase inhibitors used to enhance the antibiotic properties of other antibiotics by preventing microbial resistance. It also discusses the monobactams aztreonam and tigemonam, which have activity against gram-negative bacteria by binding to penicillin binding proteins, but no activity against gram-positive bacteria or anaerobes. These monobactams are used to treat various infections when patients cannot tolerate penicillins or cephalosporins.
- Tetracyclines are a class of broad spectrum antibiotic drugs derived from bacteria. They work by binding to the bacterial ribosome to inhibit protein synthesis and show bacteriostatic activity.
- Structurally, they contain four cyclic rings. Modifications to the structure can impact their activity. They are classified based on their duration of action as long, intermediate, or short acting.
- Common examples include tetracycline, doxycycline, and minocycline. They are used to treat various bacterial infections but have side effects like nausea, vomiting, and tooth staining when taken.
This document discusses appetite suppressants, carminatives, and digestants. It describes how appetite is regulated by factors like energy expenditure, absorption, and hormones. Obesity results from an imbalance where energy intake exceeds expenditure due to genetic, environmental, neurological, and dietary factors. Several classes of appetite suppressants are listed that work through different mechanisms in the body. Carminatives like sodium bicarbonate, peppermint oil, and ginger help expel gas from the gastrointestinal tract. Digestants contain enzymes to aid digestion and are sometimes used when enzyme production is deficient, though their general use as tonics is irrational. Specific digestive enzymes, their sources, and appropriate uses are outlined.
Sulfonamides are antibacterial drugs that work by interfering with bacterial synthesis of folic acid. They are structural analogues of para-aminobenzoic acid (PABA) that bind to and inhibit the enzyme dihydropteroate synthase. This document discusses the mechanism of action, classification, structure-activity relationships, and properties of sulfonamides. It provides examples of commonly used sulfonamides and details their structures, mechanisms, and applications in treatment. The document also addresses issues like ionization, crystalluria, and dissociation constants that are important for understanding sulfonamide properties and use.
This is lecturer notes on pharmacology & toxicology for B.V.Sc & A.H. Seventh semester students.This may useful for other institute veterinary students.Please send your comment and suggestion;jibachhashah@gmail.com,mob.9845024121
Antibiotics acting on cell wall 1 penicillins 03-05-2018Ravi Kant Agrawal
The document discusses antibacterial drugs that act on bacterial cell wall synthesis. It focuses on beta-lactam antibiotics such as penicillins, cephalosporins, carbapenems, and monobactams. These antibiotics inhibit the transpeptidase enzyme involved in cross-linking peptidoglycan, weakening the cell wall. The mechanism of action and structures of various penicillins are described in detail.
Anti Malarial Drugs of medicinal chemistryPranjal Saxena
This slide contain information about Anti Malarial Drugs and their description with the synthesis of Chloroquine and pamaquine
SAR of quinolines
Miscellaneous agents of anti Malarial
These are antibiotics having a macrocyclic
lactone ring with attached sugars. Erythromycin
is the first member discovered in the 1950s,
Roxithromycin, Clarithromycin and Azithromycin
are the later additions. Antimicrobial spectrum is narrow,
includes mostly gram-positive and a few gramnegative
bacteria, and overlaps considerably with
that of penicillin G. Erythromycin is highly active
against Str. pyogenes and Str. pneumoniae, N.
gonorrhoeae, Clostridia, C. diphtheriae and
Listeria, but penicillin-resistant Staphylococci
and Streptococci are now resistant to erythromycin
also.
All cocci readily develop resistance
to erythromycin, mostly by acquiring the
capacity to pump it out. Resistant Enterobacteriaceae
have been found to produce an erythromycin
esterase. Alteration in the ribosomal binding
site for erythromycin by a plasmid encoded
methylase enzyme is an important mechanism of
resistance in gram-positive bacteria. All the above
types of resistance are plasmid mediated. Change
in the 50S ribosome by chromosomal mutation
reducing macrolide binding a
Aminoglycosides(medicinal chemistry by p.ravisankar)Dr. Ravi Sankar
Aminoglycosides,Aminocyclitols,Source,Structures of streptomycin,Dihydrostreptomycin,A mention of other aminoglycoside antibiotics,Acid hydrolysis,Mechanism of action,SAR,Dihydrostreptomycin and its importance,therapeutic uses, toxicity.
Penicillins by Dr. Panchumarthy Ravisankar M.Pharm., Ph.D.Dr. Ravi Sankar
The document discusses penicillins, including their:
1) Historical background of discovery by Alexander Fleming in 1928 from Penicillium notatum.
2) Classification based on structure, spectrum, source and pharmacological activity, with penicillins classified under the beta-lactam class.
3) Structures of different penicillins such as penicillin G, penicillin V, methicillin, and isoxazolyl penicillins.
This document discusses beta-lactamase inhibitors such as clavulanic acid, sulbactam, and tazobactam, which inhibit beta-lactamase enzymes produced by bacteria and restore the effectiveness of beta-lactam antibiotics. Clavulanic acid inhibits a wide range of beta-lactamases. Sulbactam and tazobactam are similar to clavulanic acid but less potent. These inhibitors are often combined with antibiotics like amoxicillin and piperacillin to treat infections caused by beta-lactamase producing bacteria. Carbapenems and monobactams were also developed to be resistant to beta-l
Quinolones are synthetic antibacterial agents derived from nalidixic acid. Modern fluoroquinolones are classified into generations based on potency and spectrum of activity, with later generations having broader coverage. They work by inhibiting bacterial DNA gyrase and topoisomerase IV, preventing DNA replication. Common quinolones include norfloxacin for urinary tract infections, ciprofloxacin with activity against Pseudomonas, and sparfloxacin active against streptococci and anaerobes.
Urinary tract infections are mainly caused by bacteria like E. coli and Staphylococcus. Common symptoms include burning during urination and red or pink colored urine. Quinolones are a class of antibiotics that are highly effective against many infectious diseases, including those caused by bacteria in the urinary tract. Quinolones work by inhibiting the bacterial DNA gyrase enzyme, which is responsible for compacting DNA and allowing replication. Some examples of quinolones used to treat UTIs are ciprofloxacin, norfloxacin, and ofloxacin. Other classes of antibiotics that can be used to treat UTIs include nitrofurans, sulfa drugs, and methenamine.
This document provides an overview of antibiotics, including their historical background, classification, mechanisms of action, and examples. It focuses on penicillins and their discovery by Alexander Fleming in 1928. Penicillins are beta-lactam antibiotics that work by inhibiting bacterial cell wall synthesis. They have broad applications for treating bacterial infections. The document also discusses cephalosporins, another class of beta-lactam antibiotics derived from the fungus Cephalosporium.
Cephalosporins are β-lactam antibiotics isolated from the fungus Cephalosporium. Interest in these fungi began in 1945 with the discovery that their cultures inhibited both gram-positive and gram-negative bacteria. The first isolated compounds were cephalosporin C, cephalosporin N, and cephalosporin P. Cephalosporins are classified based on their structure, spectrum of activity, and resistance to penicillinase. They work by inhibiting transpeptidase and preventing cell wall synthesis in bacteria. Modifications to the structure can alter their properties and spectrum. β-lactamase inhibitors are used to overcome resistance from the β-lactamase enzyme.
Macrolides are a class of antibiotics derived from Saccharopolyspora erythraea (originally called Streptomyces erythreus), a type of soil-borne bacteria.
The document summarizes key information about aminoglycoside antibiotics. It discusses their discovery, examples currently used, and properties like poor absorption and administration by injection. Mechanisms of action involve binding to bacterial ribosomes to inhibit protein synthesis. Resistance can develop through enzymatic modification of the antibiotics. The structure and functional groups of the different rings that make up aminoglycosides influence their activity, spectrum, and susceptibility to resistance mechanisms.
This document discusses tetracycline antibiotics. It describes their structure, mechanism of action, derivatives, and spectrum of activity. Tetracyclines are broad-spectrum antibiotics obtained from Streptomyces bacteria. They work by inhibiting bacterial protein synthesis by binding to the 30S ribosomal subunit. There are several medically used tetracycline compounds that differ slightly in their chemical structures. Resistance can occur through efflux pumps, ribosomal protection, or enzymatic oxidation. The tetracyclines demonstrate the broadest antibacterial spectrum of any antibiotic class.
Chloramphenicol is a broad-spectrum antibiotic that was initially obtained from Streptomyces bacteria but is now produced synthetically. It inhibits bacterial protein synthesis by binding reversibly to the 50S ribosomal subunit. It is primarily bacteriostatic but can be bactericidal at high concentrations. Common adverse effects include bone marrow suppression, hypersensitivity reactions, and gray baby syndrome in neonates. It is used to treat typhoid fever, meningococcal infections, and anaerobic infections when other antibiotics cannot be used.
This document discusses beta lactamase inhibitors and monobactams. It describes clavulanic acid, sulbactam, and tazobactam, which are beta lactamase inhibitors used to enhance the antibiotic properties of other antibiotics by preventing microbial resistance. It also discusses the monobactams aztreonam and tigemonam, which have activity against gram-negative bacteria by binding to penicillin binding proteins, but no activity against gram-positive bacteria or anaerobes. These monobactams are used to treat various infections when patients cannot tolerate penicillins or cephalosporins.
- Tetracyclines are a class of broad spectrum antibiotic drugs derived from bacteria. They work by binding to the bacterial ribosome to inhibit protein synthesis and show bacteriostatic activity.
- Structurally, they contain four cyclic rings. Modifications to the structure can impact their activity. They are classified based on their duration of action as long, intermediate, or short acting.
- Common examples include tetracycline, doxycycline, and minocycline. They are used to treat various bacterial infections but have side effects like nausea, vomiting, and tooth staining when taken.
This document discusses appetite suppressants, carminatives, and digestants. It describes how appetite is regulated by factors like energy expenditure, absorption, and hormones. Obesity results from an imbalance where energy intake exceeds expenditure due to genetic, environmental, neurological, and dietary factors. Several classes of appetite suppressants are listed that work through different mechanisms in the body. Carminatives like sodium bicarbonate, peppermint oil, and ginger help expel gas from the gastrointestinal tract. Digestants contain enzymes to aid digestion and are sometimes used when enzyme production is deficient, though their general use as tonics is irrational. Specific digestive enzymes, their sources, and appropriate uses are outlined.
Sulfonamides are antibacterial drugs that work by interfering with bacterial synthesis of folic acid. They are structural analogues of para-aminobenzoic acid (PABA) that bind to and inhibit the enzyme dihydropteroate synthase. This document discusses the mechanism of action, classification, structure-activity relationships, and properties of sulfonamides. It provides examples of commonly used sulfonamides and details their structures, mechanisms, and applications in treatment. The document also addresses issues like ionization, crystalluria, and dissociation constants that are important for understanding sulfonamide properties and use.
This is lecturer notes on pharmacology & toxicology for B.V.Sc & A.H. Seventh semester students.This may useful for other institute veterinary students.Please send your comment and suggestion;jibachhashah@gmail.com,mob.9845024121
Antibiotics acting on cell wall 1 penicillins 03-05-2018Ravi Kant Agrawal
The document discusses antibacterial drugs that act on bacterial cell wall synthesis. It focuses on beta-lactam antibiotics such as penicillins, cephalosporins, carbapenems, and monobactams. These antibiotics inhibit the transpeptidase enzyme involved in cross-linking peptidoglycan, weakening the cell wall. The mechanism of action and structures of various penicillins are described in detail.
This document discusses cell wall inhibitors, specifically penicillins, cephalosporins, and carbapenems. It describes their mechanisms of action as inhibiting bacterial cell wall synthesis, their spectra of activity against gram-positive and gram-negative bacteria, and important mechanisms of resistance including beta-lactamase production. Important adverse effects and pharmacokinetics are also summarized.
This document discusses cell wall inhibitors, specifically penicillins and cephalosporins. It covers their mechanisms of action, which involve inhibiting bacterial cell wall synthesis. It describes their antimicrobial spectra against gram-positive and gram-negative bacteria. Resistance mechanisms like beta-lactamase production are also summarized. The pharmacokinetics of administration, distribution, and excretion of these drugs is covered. Finally, the document outlines some common adverse effects.
- β-Lactam antibiotics include penicillins, cephalosporins, carbapenems, and monobactams. They contain a β-lactam ring structure and inhibit bacterial cell wall synthesis.
- Penicillins were the first discovered from the mold Penicillium and include natural penicillin G as well as semi-synthetic derivatives like ampicillin. Cephalosporins were later derived from the fungus Cephalosporium and have greater gram-negative spectrum.
- Carbapenems like imipenem and meropenem have a very broad spectrum including Pseudomonas aeruginosa resistance to most β-lactamases. Monobactams such as aztre
Cell wall inhibitors like β-lactam antibiotics inhibit the final step of bacterial cell wall synthesis. The penicillins interfere with transpeptidation by binding to penicillin-binding proteins. This prevents cross-linking of peptidoglycan chains, weakening the cell wall. Extended-spectrum penicillins are effective against gram-positive and some gram-negative bacteria but resistance has increased. Adverse effects include hypersensitivity reactions, diarrhea, and nephritis, particularly with methicillin which is no longer used.
This document discusses beta lactam inhibitors and other cell wall synthesis inhibitors. It describes several classes of antibiotics that work by inhibiting bacterial cell wall synthesis including penicillins, cephalosporins, carbapenems, monobactams, and beta-lactamase inhibitors. These antibiotics share the beta-lactam ring structure and inhibit the final step of peptidoglycan synthesis in bacterial cell walls. Resistance can occur via beta-lactamase production or alterations in penicillin-binding proteins. The document provides details on the chemistry, mechanisms of action, clinical uses and adverse effects of various antibiotics in these classes.
Introduction to Antibiotics,Classification,General Mechanism of action,Penicillin,Classification of Penicillin,Moa,Structure Activity Relationship,Uses
The document summarizes the chemistry of the gram-negative cell wall and the effects of various antibiotics. It describes the general structure of the gram-negative cell wall, which has an outer membrane, peptidoglycan layer, and periplasmic space. The peptidoglycan is composed of sugars and amino acids that form a mesh-like polymer. The outer membrane contains lipopolysaccharides that protect the cell from host defenses. Several classes of antibiotics target aspects of cell wall synthesis, such as penicillins and cephalosporins which inhibit peptidoglycan cross-linking, and vancomycin which blocks transpeptidation.
This document discusses penicillin and beta-lactam antibiotics. It describes how penicillin was the first antibiotic used clinically and its mechanism of inhibiting bacterial cell wall synthesis. It also summarizes various penicillin derivatives including acid-resistant, penicillinase-resistant, and extended spectrum penicillins. Finally, it discusses beta-lactamase inhibitors like clavulanic acid that are used to overcome bacterial resistance to beta-lactam antibiotics.
This document discusses cell wall inhibitors, specifically penicillins. It describes how penicillins interfere with the last step of bacterial cell wall synthesis, resulting in osmotically unstable cells that can lyse. It outlines the mechanism of action, categories of penicillins including their spectra and mechanisms of resistance. The document also covers pharmacokinetics, adverse reactions, and briefly mentions cephalosporins.
This document discusses antimicrobial agents known as antibiotics. It defines antibiotics as substances produced by microorganisms that inhibit the growth of or destroy other microbes. The document outlines the selective toxicity of antibiotics, noting they affect bacteria differently than human cells. It provides examples of common antibiotics including penicillins and cephalosporins, describing their mechanisms of action in inhibiting bacterial cell wall synthesis and their importance in history as some of the first widely used antibiotics. The summary briefly touches on antibiotic resistance as well as adverse effects and interactions.
This document discusses antimicrobial agents known as antibiotics. It defines antibiotics as substances produced by microorganisms that inhibit the growth of or destroy other microbes. The document outlines the selective toxicity of antibiotics, noting they affect bacteria differently than human cells. It provides examples of common antibiotics including penicillins and cephalosporins, describing their mechanisms of action in inhibiting bacterial cell wall synthesis and their importance in history as some of the first widely used antibiotics. The summary briefly touches on antibiotic resistance as well as adverse effects and interactions.
ß-lactam antibiotics like penicillins and cephalosporins contain a ß-lactam ring which is essential for their antibacterial activity. Penicillin was the first antibiotic discovered by Alexander Fleming in 1928. It works by interfering with bacterial cell wall synthesis. There are various generations of cephalosporins that are effective against different bacteria. Both penicillins and cephalosporins can cause hypersensitivity reactions and disrupt gut flora. Other ß-lactam classes include carbapenems and monobactams which have similar mechanisms of action and side effects.
Penicillin and other beta-lactam antibiotics work by inhibiting the final step of bacterial cell wall synthesis (transpeptidation or cross-linkage). This exposes the cell membrane which is structurally less stable. They inactivate bacterial enzymes called penicillin-binding proteins that are involved in cell wall synthesis and maintenance of cell morphology. Cephalosporins have a similar mechanism of action, inhibiting cell wall synthesis and activating autolysin enzymes. Carbapenems have broad-spectrum activity and are resistant to beta-lactamases. Vancomycin inhibits cell wall synthesis by binding to the D-alanyl-D-alanine portion of peptidoglycan precursors.
This document summarizes various classes of antimicrobial agents including their history, mechanisms of action, resistance, and adverse effects. It discusses beta-lactam antibiotics like penicillins and cephalosporins, aminoglycosides, quinolones, and macrolide antibiotics. It provides details on their structures, mechanisms of inhibiting bacterial cell wall synthesis or protein synthesis, and common resistance mechanisms like beta-lactamase production or modification of drug targets.
This document discusses cell wall inhibiting antibiotics, specifically penicillins and cephalosporins. It describes how these drugs interfere with bacterial cell wall synthesis by inactivating penicillin-binding proteins, inhibiting transpeptidation and causing cell lysis. Resistance mechanisms like beta-lactamase production and changes to penicillin-binding proteins are also summarized. The antibiotic classes covered include penicillins, cephalosporins, carbapenems, monobactams and vancomycin.
The document summarizes key information about penicillins including their structure, classification, mechanism of action, resistance, pharmacokinetics, adverse reactions, treatment of reactions, contraindications and drug interactions. It describes the core structure of penicillins including the thiazolidine and β-lactam rings. It classifies penicillins into natural, anti-staphylococcal, extended spectrum, and anti-pseudomonal categories. It explains their mechanism of inhibiting bacterial cell wall synthesis and common resistance mechanisms like β-lactamase production.
beta lactam antibiotics,aminoglycosides, quinolones and macrolide antibioticsmohammed muzammil
This document provides information on beta-lactam antibiotics (penicillins, cephalosporins, monobactams, carbapenems), aminoglycosides, and quinolones. It describes the classes of antibiotics, their mechanisms of action, which involve inhibiting bacterial cell wall synthesis or protein synthesis, and mechanisms of resistance. It also discusses specific examples within each class and their properties, indications, and side effects.
This document provides an overview of different classes of antibiotics, including β-lactam antibiotics (penicillins, cephalosporins, carbapenems, monobactams), aminoglycosides, and tetracyclines. It discusses the origin, classification, mechanisms of action, structure-activity relationships, and examples of drugs within each class. In particular, it focuses on the characteristics and development of penicillins and cephalosporins, which are the most widely used β-lactam antibiotics. It also briefly mentions β-lactamase inhibitors that are often used in combination with other antibiotics to enhance their effectiveness.
This document provides an overview of urinary tract infections (UTIs). It discusses what constitutes a UTI, common causes like E. coli, and risk factors like female anatomy. Symptoms vary by age but include issues like frequency and pain. Diagnosis involves urine tests to check for bacteria, white blood cells, and nitrites. Treatment generally involves antibiotics like trimethoprim that achieve high urine concentrations. Duration depends on the infection type, with uncomplicated cystitis often treated with a 3 day course and pyelonephritis requiring longer treatment.
This document provides information on various classes of analgesics and anti-inflammatory drugs (NSAIDs). It discusses narcotic analgesics, antipyretics, classifications of NSAIDs including salicylic acid derivatives, pyrazolones, indoleacetic acids, anthranilic acids, and arylpropionic acids. Specific NSAIDs covered include oxyphenbutazone, indomethacin, mefenamic acid, piroxicam, diclofenac sodium, ibuprofen, and celecoxib. The document outlines their chemical structures, mechanisms of action, uses, syntheses and side effects.
Patent and Generic Pharmaceutical Ethics
When a new drug is developed, the pharmaceutical company is initially granted a patent for around 20 years to exclusively sell the drug under a brand name. Once the patent expires, generic drug companies can produce versions of the drug. Generics must be proven to be equivalent to the brand version in dosage, safety, and performance to gain FDA approval. This increased competition brings drug prices down substantially, improving access and affordability for patients.
This document discusses polymers used in drug delivery. Polymers are macromolecules made of repeating monomer units. They can be classified based on monomer type, arrangement, structure, properties, source, form, and biodegradability. Copolymers contain two monomers, while homopolymers contain one. Polymers have applications in conventional dosage forms like tablets and liquids, as well as controlled drug delivery systems. Biodegradable polymers break down in response to chemical reactions like hydrolysis. Their degradation can be hydrolytic, enzymatic, and affected by various factors.
The document discusses key steps in the manufacturing process of solid dosage forms including granulation, drying, blending, tableting, and coating if applicable. It identifies critical process parameters that can significantly affect drug release such as drug particle size, excipient quality, granulation equipment, process variables like binder amount and time, and manufacturing steps. The document also provides examples of process variables and responses measured for solid dosage forms and diagrams of tablet manufacturing equipment.
This document discusses HIV infection and AIDS. It begins by noting that AIDS was first recognized in 1981 in homosexual men with immune deficiencies. It then discusses how HIV is transmitted, primarily through sexual intercourse, needle sharing, blood transmission, and from mother to child. The document outlines the structure of HIV, which is a retrovirus that infects CD4 cells. It explains how HIV replicates by converting its RNA to DNA and integrating into the host cell genome. This causes a depletion of CD4 cells over time, leading to immunosuppression and susceptibility to other infections and illnesses. The document covers clinical manifestations of HIV at different stages, as well as methods for testing, monitoring, and treating HIV, including antiretroviral drugs that
Sterile preparation techniques involve maintaining cleanliness levels from grades A through F to minimize contamination. Grade A areas have the highest level of protection for aseptic processing. Various sources of possible contamination like premises, air, personnel and materials are controlled. Personnel follow hygiene procedures and wear protective clothing appropriate for the cleanliness grade. Sampling locations are chosen based on factors like criticality and proximity to products to monitor environmental quality.
This document discusses anti-malarial drugs, focusing on cinchona alkaloids like quinine. It describes the chemical classification of anti-malarials and the medicinal chemistry of cinchona alkaloids. Specifically, it details the extraction of quinine from cinchona bark, its chemical structure, structure-activity relationships, mechanisms of action including inhibition of hemozoin biocrystallization, and therapeutic uses while noting its replacement due to undesirable side effects.
This document discusses thyroid disorders of hyperthyroidism and hypothyroidism. It defines them as conditions resulting from too little or too much thyroid hormone production respectively. It describes the physiology of thyroid hormone regulation and the negative feedback loop. The causes of hyperthyroidism include Graves' disease, toxic multinodular goiter, subacute thyroiditis, toxic single adenoma, and others. The treatment options for hyperthyroidism discussed are symptom relief medications, anti-thyroid drugs, radioactive iodine treatment, and thyroidectomy.
This document provides an overview of sterilization including:
- Definitions of key terms like sterilization, antiseptic, bacteriostatic, and viable
- Classification of sterilization methods into terminal and non-terminal processes
- Parameters used to measure sterilization effectiveness like D-value and z-value
- Methods of controlling microorganisms through physical sterilization techniques like heat and radiation or chemical sterilization agents
- Guidance on sterilization from regulatory bodies like the FDA
- Conclusions on the importance of sterilization in various applications like pharmaceuticals and healthcare
This document summarizes key information about pyrimethamine, an antimalarial drug:
- Pyrimethamine belongs to a class of antimalarial drugs containing a 6-membered heterocyclic ring with two nitrogen atoms one carbon atom apart.
- Its structure and modifications were studied extensively, finding maximum activity when a chlorophenyl group is attached at position 5 and an ethyl group at position 6.
- Pyrimethamine works by inhibiting dihydrofolate reductase in plasmodium, preventing synthesis of folic acid and thus inhibiting nucleic acid and replication of the plasmodium parasite.
Patent and Generic Pharmaceutical Ethics
When a new drug is developed, the pharmaceutical company is initially granted a patent for around 20 years to exclusively sell the drug under a brand name. Once the patent expires, generic drug companies can produce versions of the drug. Generics must be proven to be equivalent to the brand version in dosage, safety, and performance to gain FDA approval. This increased competition brings drug prices down substantially, improving access and affordability for patients.
This document provides a classification of anticancer drugs into 9 main categories:
1) Alkylating agents which damage DNA like nitrogen mustards and platinum complexes.
2) Antimetabolites which are analogs of nutrients needed for cell growth such as methotrexate and 5-fluorouracil.
3) Antibiotics including anthracyclines derived from bacteria and bleomycin which is a quinone derivative.
4) Natural and semi-synthetic plant products that inhibit microtubules and topoisomerases, including taxanes, vinca alkaloids, and camptothecins.
5) Steroidal hormones and antagonists such as tamoxifen,
The document provides information on pharmaceutical care including its history and key concepts. It discusses the staircase approach to pharmaceutical care and outlines the practitioner's responsibilities. These include understanding the patient, assessing their medication needs and therapy, identifying any drug-related problems, developing a care plan, and conducting follow-up evaluations. It also covers assessing the patient's medication experience, types of drug therapy problems, and the importance of the therapeutic relationship and patient-centered approach.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Training: ISO/IEC 27001 Information Security Management System - EN | PECB
ISO/IEC 42001 Artificial Intelligence Management System - EN | PECB
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A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
7. History of Penicillins
• Discovered by Alexander Fleming in 1928.
• Was isolated from fungus Penicillium notatum which is now
prepared from Penicillium chrysogenum.
• Florey and Chain isolated penicillins using freeze drying and
chromatography in 1944.
8. Chemistry of Penicillins
• Penicillins is a subclass of β-lactam antibiotics containing β-
lactam ring fused with 5 membered S containing heterocyclic ring
known as thiazolidine.
• The bicyclic heterocyclic ring formed by this fusion is known as
6-amino penicillanic acid (6-APA) nucleus.
11. Chemistry of Penicillins
• The C-3, 5 and 6 are asymmetric which interfere with the
planarity of lactam bond.
• Lack of planarity prevents resonance of the lactam nitrogen
with its carbonyl group.
• Consequently, the β-lactam ring is more strained and unstable
due to lack of resonance.
• Therefore, β-lactam ring is reactive and more sensitive to
nucleophilic attack compared to normal planar amides.
12. Degradation of Penicillins
• The most unstable β-lactam amide bond in penicillin molecule
undergoes hydrolysis slowly in water.
• But heating, presence of alkali and lactamase enzyme accelerate
the hydrolysis. The hydrolysis produces penicilloic acid which is
decarboxylated to form penilloic acid.
• Penicillins also undergo acid catalyzed hydrolysis. The main end
products of acid catalyzed hydrolysis are penicillamine, penilloic
acid and penalloaldehyde.
15. Prevention of Degradation of Penicillins
• In-vitro degradation of penicillins can be retarded by keeping pH
of solutions 6-6.8 and by refrigerating them.
• Metal ions such as Hg, Zn and Cu catalyze the degradation, and
should be avoided as packing materials.
16. Structure Activity Relationship
• The chemical constituents attached to penicillin nucleus can
greatly influence the stability of the penicillins and spectrum
of activity.
18. Structure Activity Relationship
• Substitution of side chain R with an electron-withdrawing group
decreases the electron-density on the side chain carbonyl and
protects penicillins from acid degradation.
• This property has clinical implication because these compounds
survive passage through the stomach and can be given orally for
systemic activity.
19. Structure Activity Relationship
• The more lipophilic chain attached to the side chain, the more
protein bound is the antibiotic.
• It prevents the enzymatic degradation of penicillins and
increases the half life.
• However, it reduces the effective bactericidal concentration of
penicillins.
21. Structure Activity Relationship
If acyl amino chain is attached with a bulkier group, penicillins
become stable towards penicillinase enzyme.
Methicillin
22. Structure Activity Relationship
The introduction of an ionized or polar group into the -position of the
side chain benzyl carbon atom of penicillin G confers activity against
Gram-negative bacilli. Hence, derivatives with an ionized -amino
group, such as ampicillin and amoxicillin, are generally effective
against such Gram-negative genera as Escherichia, Klebsiella,
Haemophilus, Salmonella, Shigella, and non–indole-producing
Proteus.
23. Structure Activity Relationship
Furthermore, activity against penicillin G–sensitive, Gram-positive
species is largely retained. The introduction of an -amino group in
ampicillin (or amoxicillin) creates an additional chiral center.
Extension of the antibacterial spectrum brought about by the
substituent applies only to the D-isomer, which is 2 to 8 times more
active than either the L-isomer or benzylpenicillin (which are
equiactive) against various species of the aforementioned genera of
Gram-negative bacilli.
24. Mechanism of Action-Cell Wall Functions
The bacterial cells are covered by an outer most layer called cell
wall which serves the following functions;
• Semipermeable barrier for the selective passage of substances.
• Strong barrier to protect the bacterial cell changes in osmotic
pressure.
• To prevent bacterial cell from digestion by host enzymes.
25. Mechanism of Action-Cell Wall Composition
• The cell wall is a spongy gel forming layer consisting of
alternating sugars N-acetyl glucosamine (NAG) and N-acetyl
muramic acid (NAM) linked in a polymer chain.
• A complex polymeric sheet is formed by many such
peptidoglycan chains.
• The polymeric sheets are crossed linked to form a thick cell wall.
• A small peptide chain consisting of L-alanyl-D-glutamyl-L-lysyl-
D-alanin is attached to NAM unit by a peptide bond.
27. Mechanism of Action-Cell Wall Composition
• The protruding peptide chain cross links the two polymeric sheets
through a peptide bond between the terminal D-alanyl unit and of
one peptide chain to lysyl unit of an adjacent tetrapeptide strand
through a pentaglycine unit.
• Cross linking is catalyzed by enzyme called transpeptidase found
in the inner part of cell membrane.
• Penicillins bind to this enzyme and hence are also called as
penicillin binding proteins (PBP).
28. Mechanism of Action
• There are many types of PBPs (PBP-1a, PBP-1b, PBP-2, PBP-2a,
PBP-3) which are involved in construction and repair of cell wall.
• Penicillins bind to PBPs and inhibit their enzymatic properties
and prevent the construction and repair of cell wall.
• Prevention of cell wall synthesis exposes the dividing and young
bacteria to survive, resulting in killing of bacterial cells.
• As a result, penicillins act as bactericidal antibiotics.
30. Allergic Reactions to Penicillins
• The origin of allergy is hepatic reaction which involves formation
of antigenic penicilloyl proteins due to reaction of nucleophilic
group of β-lactam ring with host proteins.
• Hence, this side effect is caused by the pharmacophore and is
unlikely to overcome with the molecular manipulations.
• Allergy to penicillins is expressed as mild drug rash or itching and
is of delayed onset.
• Topical wheal-and-flare test may be performed.
31. Allergic reactions to Penicillins
• Occasionally the reaction is immediate and profound.
• It may include the cardiovascular collapse and shock.
• Erythromycin and clindamycin are useful alternatives for therapy
in many cases of penicillin allergy.
• Penicillins are prepared in facilities separate from those used to
prepare other drugs to prevent cross-contamination and possible
sensitization.
32. Resistance to Penicillins
• The first mode of resistance is due to enzymatic hydrolysis of the
beta-lactam ring.
• If the bacterium produces the enzymes beta-lactamase or
penicillinase, these enzymes will break open the beta lactam ring
rendering the antibiotic ineffective.
• 2nd mode of beta-lactam resistance is due to possession of altered
penicillin-binding-proteins (PBPs).
33. Resistance to Penicillins
• Beta-lactams cannot bind effectively to these PBPs as a result these
antibiotics become less effective in disrupting the cell wall.
• Resistance to beta lactamase can be reduced by carrying out some
structural modifications in the parent compound.
34. Classification of Penicillins
• Penicillins can be classified based on their sources, chemistry,
pharmacokinetic properties, resistance to enzymatic spectrum of
activity, and clinical uses.
• Penicillins may be biosynthetic, semisynthetic, or synthetic; acid-
resistant or not; orally or (only) parenterally active; and resistant to
lactamases (penicillinases) or not.
• They may have a narrow, intermediate, broad, or extended spectrum
of antibacterial activity and may be intended for multipurpose or
limited clinical use.
38. Benzylpenicillin (Penicillin G)
• Penicillin G is unstable under acidic conditions of stomach
• Parenteral route of administration.
• Self destructive mechanism in its structure because of influence of
acyl side chain.
• Effective mainly against Gram positive cocci such as streptococci
and staphylococci.
• It is also effective against Neisseria gonorrhoeae and
Haemophilus influenza
• Many once sensitive bacteria are now resistant.
• Used in upper and lower RTIs, genitourinary tract infections
40. Phenoxymethyl penicillin (Penicillin V)
• Produced by fungus in a medium rich in phenoxy acetic acid
• Can also be prepared by semi-synthesis and is comparatively more
stable than penicillin G
• Stability is due to electronegative oxygen atom at C-7 amide side
chain inhibiting participation in beta-lactam bond hydrolysis
• It was the first oral penicillin
• Antimicrobial spectrum is roughly same as that of penicillin G.
• Same sensitivity to beta-lactamases as penicillin G and almost same
allergenicity.
42. Methicillin
• Although it is not used today but methicillin was first penicillinase
resistant penicillin used clinically.
• Unstable is gastric acid (half life = 5 min at pH = 2)
• Increased bulk resulting from the addition of dimethoxy benzoyl
group to 6-APA leads to methicillin (beta-lactamase resistant)
• Methicillin has significantly narrower antimicrobial spectrum so it
was limited to use clinically only for infections caused by beta-
lactamase producing Staphylococcus aureus and few other infections
43. Methicillin
• MRSA refers to methicillin resistant staphylococcus aureus.
• Resistance mechanism includes altered PBPs.
• Methicillin is also an effective inducer of penicillinases.
44. Ampicillin
• Ampicillin is an amino benzylpenicillin and is a semisynthetic
penicillin.
• D-Ampicillin, is significantly more active than L-ampicillin.
45. Ampicillin
• Antibacterial spectrum broader than that of penicillin G.
• This product is active against the same Gram-positive organisms
that are susceptible to other penicillins, and it is more active
against some Gram-negative bacteria and enterococci than are
other penicillins.
• Amino group plays an important role in the broader activity.
• Amino group confers an ability to cross cell wall barriers that are
impenetrable to other penicillins.
46. Amoxicillin
• Amoxicillin, is the p-hydroxy analog of ampicillin.
• Amoxicillin is a fine, white to off-white, crystalline powder that is
sparingly soluble in water.
• It is available in various oral dosage forms
47. Amoxicillin
• Its antibacterial spectrum is nearly identical with that of
ampicillin.
• It is resistant to acid, susceptible to alkaline and lactamase
hydrolysis, and weakly protein bound.
• Orally administered amoxicillin possesses significant advantages
over ampicillin, including more complete GI absorption to give
higher plasma and urine levels, less diarrhea, and little or no effect
of food on absorption.
48. Amoxicillin
• Thus, amoxicillin has largely replaced ampicillin for the
treatment of certain systemic and urinary tract infections for
which oral administration is desirable.
• However, amoxicillin is less effective than ampicillin in the
treatment of dysentery, presumably because of its greater GI
absorption.
• Oral absorption of amino benzyl penicillins (e.g., ampicillin and
amoxicillin) and cephalosporins is carrier mediated thus
explaining their generally superior oral activity.
49. Oxacillin
• Oxacillin sodium, (5-methyl3-phenyl-4-isoxazolyl) penicillin
sodium monohydrate, is the salt of a semisynthetic penicillin
that is highly resistant to inactivation by penicillinase.
• The steric effects of the 3-phenyl and 5-methyl groups of the
isoxazolyl ring prevent the binding of this penicillin to the
lactamase active site and, thereby, protect the lactam ring from
degradation in much the same way as has been suggested for
methicillin.
50. Cloxacillin
• It is also relatively resistant to acid hydrolysis and, therefore,
may be administered orally with good effect.
• The chlorine atom ortho to the position of attachment of the
phenyl ring to the isoxazole ring enhances the activity of
cloxacillin sodium over that of oxacillin, not by increasing its
intrinsic antibacterial activity but by enhancing its oral
absorption, leading to higher plasma levels.
• In almost all other respects, it resembles oxacillin.
51. Dicloxacillin
• The substitution of chlorine atoms on both
carbons ortho to the position of attachment of
the phenyl ring to the isoxazole ring further enhance the stability of
dicloxacillin sodium and produce high plasma concentrations.
• Progressive halogen substitution, however, also increases the
fraction bound to protein in the plasma, potentially reducing the
concentration of free antibiotic in plasma and tissues.
• Its medicinal properties and use are the same as those of
cloxacillin sodium.