Chloramphenicol is a broad-spectrum antibiotic that inhibits bacterial protein synthesis. It binds reversibly to the 50S subunit of bacterial ribosomes, blocking the formation of peptide bonds between amino acids. While effective against many gram-positive and gram-negative bacteria, its use is now reserved for life-threatening infections due to risks of bone marrow suppression and gray baby syndrome in neonates. Proper dosing and alternative antibiotics are preferred whenever possible due to these toxicities.
The document discusses various anthelmintic drugs, including their mechanisms of action, pharmacokinetics, therapeutic uses, and adverse effects. It focuses on commonly used drugs like albendazole, mebendazole, piperazine, diethylcarbamazine, ivermectin, praziquantel, and niclosamide which are used to treat infections caused by different types of intestinal worms and parasites. The document also provides an overview of the epidemiology and control of helminth infections.
Fluoroquinolones are a class of broad-spectrum antibacterial agents derived from nalidixic acid. They work by inhibiting bacterial DNA gyrase and topoisomerase IV, blocking DNA synthesis. Resistance can occur via mutations in the quinolone binding region of these target enzymes or changes in bacterial permeability. Fluoroquinolones are classified into generations based on spectrum of activity and are well-absorbed orally with varying tissue distribution and drug interactions. Adverse effects include gastrointestinal, central nervous system, and musculoskeletal issues. Ciprofloxacin and levofloxacin are two commonly used fluoroquinolones with activity against both gram-negative and gram-positive pathogens.
Tetracyclines are a class of broad-spectrum bacteriostatic antibiotics that work by binding to the 30S subunit of bacterial ribosomes and inhibiting protein synthesis. They are effective against many gram-positive and gram-negative bacteria, as well as anaerobes, rickettsiae, chlamydiae, mycoplasmas, and protozoa. Tetracyclines have a range of pharmacokinetic properties from short-acting to long-acting drugs. They are subject to resistance via efflux pumps, ribosomal protection proteins, and enzymatic inactivation. Common adverse effects include gastrointestinal issues, staining of teeth and bones, and photosensitivity.
Tetracyclines are Octahydro napthacene derivatives which are bacteriostatic potent broad spectrum antibiotics and are the most widely prescribed form of antibiotic after penicillins.
TETRA means = four
CYCL means = hydrocarbon rings
INE means = derivation.
Tetracyclines are introduced 50 years ago as potent broad spectrum antibiotics.
They are biosynthesized form acetic acid and propionic acid units in microorganisms.
Macrolides are a class of antibiotics derived from Saccharopolyspora erythraea (originally called Streptomyces erythreus), a type of soil-borne bacteria.
This document summarizes various anthelmintic drugs used to treat parasitic worm infections. It discusses the drug classes including benzimidazoles, quinolines, piperazine derivatives, vinyl pyrimidines, amides, natural products, and others. It provides details on specific drugs like albendazole, mebendazole, thiabendazole, oxamniquine, praziquantel, piperazine citrate, diethyl carbamazine, pyrantel pamoate, niclosamide, ivermectin, levamisole, metronidazole, and niridazole. It covers their mechanisms of action, structure-
The fixed dose combination of trimethoprim and sulfamethoxazole is called cotrimoxazole.
Adverse Drug Reaction, Spectrum, Resistance and Use of Cotrimoxazole.
The document discusses various anthelmintic drugs, including their mechanisms of action, pharmacokinetics, therapeutic uses, and adverse effects. It focuses on commonly used drugs like albendazole, mebendazole, piperazine, diethylcarbamazine, ivermectin, praziquantel, and niclosamide which are used to treat infections caused by different types of intestinal worms and parasites. The document also provides an overview of the epidemiology and control of helminth infections.
Fluoroquinolones are a class of broad-spectrum antibacterial agents derived from nalidixic acid. They work by inhibiting bacterial DNA gyrase and topoisomerase IV, blocking DNA synthesis. Resistance can occur via mutations in the quinolone binding region of these target enzymes or changes in bacterial permeability. Fluoroquinolones are classified into generations based on spectrum of activity and are well-absorbed orally with varying tissue distribution and drug interactions. Adverse effects include gastrointestinal, central nervous system, and musculoskeletal issues. Ciprofloxacin and levofloxacin are two commonly used fluoroquinolones with activity against both gram-negative and gram-positive pathogens.
Tetracyclines are a class of broad-spectrum bacteriostatic antibiotics that work by binding to the 30S subunit of bacterial ribosomes and inhibiting protein synthesis. They are effective against many gram-positive and gram-negative bacteria, as well as anaerobes, rickettsiae, chlamydiae, mycoplasmas, and protozoa. Tetracyclines have a range of pharmacokinetic properties from short-acting to long-acting drugs. They are subject to resistance via efflux pumps, ribosomal protection proteins, and enzymatic inactivation. Common adverse effects include gastrointestinal issues, staining of teeth and bones, and photosensitivity.
Tetracyclines are Octahydro napthacene derivatives which are bacteriostatic potent broad spectrum antibiotics and are the most widely prescribed form of antibiotic after penicillins.
TETRA means = four
CYCL means = hydrocarbon rings
INE means = derivation.
Tetracyclines are introduced 50 years ago as potent broad spectrum antibiotics.
They are biosynthesized form acetic acid and propionic acid units in microorganisms.
Macrolides are a class of antibiotics derived from Saccharopolyspora erythraea (originally called Streptomyces erythreus), a type of soil-borne bacteria.
This document summarizes various anthelmintic drugs used to treat parasitic worm infections. It discusses the drug classes including benzimidazoles, quinolines, piperazine derivatives, vinyl pyrimidines, amides, natural products, and others. It provides details on specific drugs like albendazole, mebendazole, thiabendazole, oxamniquine, praziquantel, piperazine citrate, diethyl carbamazine, pyrantel pamoate, niclosamide, ivermectin, levamisole, metronidazole, and niridazole. It covers their mechanisms of action, structure-
The fixed dose combination of trimethoprim and sulfamethoxazole is called cotrimoxazole.
Adverse Drug Reaction, Spectrum, Resistance and Use of Cotrimoxazole.
A Power point presentation on Betalactam antibiotics suitable for undergraduate medical students. This Ppt is already presented in theory class lectures to the students of NEIGRIHMS, Shillong, Meghalaya
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.
Ketoconazole was the first orally effective broad-spectrum antifungal but has been replaced by newer azoles. It acts by inhibiting ergosterol biosynthesis. Common side effects include nausea and loss of hair/libido. It interacts with many drugs by inhibiting CYP3A4. Fluconazole has a wider spectrum than ketoconazole and good CSF penetration. Itraconazole and voriconazole are broad-spectrum second-generation triazoles. Terbinafine inhibits squalene epoxidase and accumulates in the skin. Topical agents like clotrimazole, miconazole and econazole are used to treat superficial fung
Aminoglycosides are a class of antibiotics that bind to the 30S ribosomal subunit of bacteria, preventing proper initiation complex formation and causing misreading of the genetic code, which leads to bacterial death. They are administered parenterally due to poor oral absorption and distributed poorly outside of extracellular fluid. While effective against many gram-negative bacteria, aminoglycosides can cause nephrotoxicity, ototoxicity, and neuromuscular blockade as side effects if not properly dosed based on renal function.
This document provides information on beta-lactam antibiotics including penicillins, cephalosporins, and beta-lactamase inhibitors. It discusses the classes of penicillins such as phenoxymethylpenicillin, methicillin, cloxacillin, aminopenicillins, carboxypenicillins, and ureidopenicillins. It describes the structures, spectra of activity, pharmacokinetics, uses and adverse effects of various penicillin derivatives. The summary focuses on the key classes of beta-lactam antibiotics and their properties.
This document discusses two broad spectrum antibiotics - chloramphenicol and tetracyclines. It provides details on their mechanisms of action, resistance mechanisms, pharmacokinetics, therapeutic uses, and adverse effects. Chloramphenicol and tetracyclines are bacteriostatic and inhibit bacterial protein synthesis. Their widespread use led to many resistant bacterial strains. Recent interest in their clinical use has increased due to fewer resistant bacteria. The document reviews specifics on the properties and use of each antibiotic.
This document discusses fluoroquinolone antibiotics. It describes their spectrum of activity, mechanism of action, pharmacokinetics, uses, and adverse effects. Fluoroquinolones are broad-spectrum antibacterial drugs used commonly due to their oral availability and favorable pharmacokinetics. However, there is increasing concern about emerging resistance. Common fluoroquinolones discussed include norfloxacin, ciprofloxacin, ofloxacin, levofloxacin, and moxifloxacin.
This document discusses tetracycline antibiotics. It notes that tetracyclines suppress a wide range of gram-positive and gram-negative bacteria, as well as other microorganisms. They work by inhibiting protein synthesis by binding to the 30S subunit of bacterial ribosomes. Common side effects include gastrointestinal irritation. Tetracyclines are generally not recommended as first-line treatment but may be used for selected infections like rickettsial diseases. Newer tetracycline derivatives like doxycycline and minocycline have improved properties like better absorption and tissue penetration.
- Penicillins are a major class of antibiotics that were the first discovered from the mold Penicillium. They work by inhibiting the final step of bacterial cell wall synthesis through binding to penicillin-binding proteins. This disrupts cell wall formation and causes cell lysis.
- There are different generations/classes of penicillins that vary in their spectra of activity and resistance to bacterial beta-lactamases. Oral forms are absorbed from the gastrointestinal tract while injectable forms provide more sustained drug levels. Adverse effects include hypersensitivity reactions and gastrointestinal issues.
The document discusses three topics:
1. Fluoroquinolones are a class of antibiotics that work by inhibiting bacterial DNA gyrase and topoisomerase IV. Their use has contributed to the spread of antimicrobial resistance. Common examples include ciprofloxacin and levofloxacin.
2. Folate antagonists are antibiotics that inhibit bacterial folate synthesis. This includes sulfonamides, which block de novo folate synthesis, and trimethoprim, which prevents conversion of dihydrofolic acid to tetrahydrofolic acid.
3. Urinary tract antiseptics are briefly mentioned but not described.
Ciprofloxacin is a synthetic broad spectrum fluoroquinolone antibiotic that binds to and inhibits bacterial DNA gyrase, an enzyme essential for DNA replication. It is more active against Gram-negative bacteria. Ciprofloxacin lactate is manufactured by condensing Fluoroquinolonic Acid with piperazine and other compounds, then treating it with lactic acid to form Ciprofloxacin Lactate. The global market for ciprofloxacin hcl is growing due to its increasing use to treat infections in the urogenital, respiratory, and gastrointestinal systems as well as typhoid, bone and joint infections, and more.
This document discusses beta-lactam antibiotics, including penicillins. It describes how penicillins work by inhibiting bacterial cell wall synthesis through binding to penicillin-binding proteins. This prevents cross-linking of peptidoglycan and kills bacteria. It classifies penicillins as narrow spectrum (natural penicillins) or broad spectrum (aminopenicillins, antipseudomonal penicillins). Common adverse effects include allergic reactions and disruption of normal gut flora. Resistance can develop through plasmids transferring resistance genes.
- 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
Quinolones were first developed in the 1960s and can be classified into generations based on their antimicrobial activity. First generation quinolones were active against gram-negative bacteria but not Pseudomonas. Later generations showed increased activity against gram-positive pathogens and mycobacteria. Quinolones act by inhibiting bacterial DNA gyrase and topoisomerase IV, blocking DNA synthesis. They are potent against a variety of bacteria including E. coli, Salmonella, and Staphylococcus. However, resistance may develop via mutations in genes encoding DNA gyrase/topoisomerase IV or active drug transport.
This document discusses cephalosporins, a class of beta-lactam antibiotics. It describes their mechanism of action as inhibiting transpeptidases called penicillin binding proteins, disrupting the synthesis of bacterial cell walls. Cephalosporins are divided into five generations based on their spectrum of activity and resistance to beta-lactamases. Each newer generation has increased activity against gram-negative rods and decreased activity against gram-positive cocci. The document provides examples of therapeutic uses, dosages, and adverse effects for each generation of cephalosporins. It highlights that the fifth generation cephalosporin ceftarolinefosamil was approved in 2010 and is effective against methicillin
Antibiotics inhibiting protein synthesis 3 chloramphenicol and macrolides 03 ...Ravi Kant Agrawal
1. Chloramphenicol and macrolides like erythromycin inhibit protein synthesis in bacteria by binding to the 50S subunit of the bacterial ribosome, preventing proper alignment and peptide bond formation.
2. Chloramphenicol has broad-spectrum activity but is limited in clinical use due to potential bone marrow toxicity. It maintains activity against many gram-positive and gram-negative bacteria as well as some anaerobes.
3. Macrolides bind tightly to the P site of the bacterial ribosome, blocking translocation and translation. They are effective against a variety of bacteria and atypical pathogens.
Chloramphenicol is an antibiotic produced by Streptomyces venezuelae. It inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit, preventing binding of aminoacyl tRNA and inhibiting peptide bond formation. It can also inhibit mitochondrial protein synthesis. Chloramphenicol is administered orally or intravenously and is well absorbed. It is indicated for serious infections such as meningitis or typhoid fever. However, it carries risks of bone marrow suppression and aplastic anemia.
A Power point presentation on Betalactam antibiotics suitable for undergraduate medical students. This Ppt is already presented in theory class lectures to the students of NEIGRIHMS, Shillong, Meghalaya
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.
Ketoconazole was the first orally effective broad-spectrum antifungal but has been replaced by newer azoles. It acts by inhibiting ergosterol biosynthesis. Common side effects include nausea and loss of hair/libido. It interacts with many drugs by inhibiting CYP3A4. Fluconazole has a wider spectrum than ketoconazole and good CSF penetration. Itraconazole and voriconazole are broad-spectrum second-generation triazoles. Terbinafine inhibits squalene epoxidase and accumulates in the skin. Topical agents like clotrimazole, miconazole and econazole are used to treat superficial fung
Aminoglycosides are a class of antibiotics that bind to the 30S ribosomal subunit of bacteria, preventing proper initiation complex formation and causing misreading of the genetic code, which leads to bacterial death. They are administered parenterally due to poor oral absorption and distributed poorly outside of extracellular fluid. While effective against many gram-negative bacteria, aminoglycosides can cause nephrotoxicity, ototoxicity, and neuromuscular blockade as side effects if not properly dosed based on renal function.
This document provides information on beta-lactam antibiotics including penicillins, cephalosporins, and beta-lactamase inhibitors. It discusses the classes of penicillins such as phenoxymethylpenicillin, methicillin, cloxacillin, aminopenicillins, carboxypenicillins, and ureidopenicillins. It describes the structures, spectra of activity, pharmacokinetics, uses and adverse effects of various penicillin derivatives. The summary focuses on the key classes of beta-lactam antibiotics and their properties.
This document discusses two broad spectrum antibiotics - chloramphenicol and tetracyclines. It provides details on their mechanisms of action, resistance mechanisms, pharmacokinetics, therapeutic uses, and adverse effects. Chloramphenicol and tetracyclines are bacteriostatic and inhibit bacterial protein synthesis. Their widespread use led to many resistant bacterial strains. Recent interest in their clinical use has increased due to fewer resistant bacteria. The document reviews specifics on the properties and use of each antibiotic.
This document discusses fluoroquinolone antibiotics. It describes their spectrum of activity, mechanism of action, pharmacokinetics, uses, and adverse effects. Fluoroquinolones are broad-spectrum antibacterial drugs used commonly due to their oral availability and favorable pharmacokinetics. However, there is increasing concern about emerging resistance. Common fluoroquinolones discussed include norfloxacin, ciprofloxacin, ofloxacin, levofloxacin, and moxifloxacin.
This document discusses tetracycline antibiotics. It notes that tetracyclines suppress a wide range of gram-positive and gram-negative bacteria, as well as other microorganisms. They work by inhibiting protein synthesis by binding to the 30S subunit of bacterial ribosomes. Common side effects include gastrointestinal irritation. Tetracyclines are generally not recommended as first-line treatment but may be used for selected infections like rickettsial diseases. Newer tetracycline derivatives like doxycycline and minocycline have improved properties like better absorption and tissue penetration.
- Penicillins are a major class of antibiotics that were the first discovered from the mold Penicillium. They work by inhibiting the final step of bacterial cell wall synthesis through binding to penicillin-binding proteins. This disrupts cell wall formation and causes cell lysis.
- There are different generations/classes of penicillins that vary in their spectra of activity and resistance to bacterial beta-lactamases. Oral forms are absorbed from the gastrointestinal tract while injectable forms provide more sustained drug levels. Adverse effects include hypersensitivity reactions and gastrointestinal issues.
The document discusses three topics:
1. Fluoroquinolones are a class of antibiotics that work by inhibiting bacterial DNA gyrase and topoisomerase IV. Their use has contributed to the spread of antimicrobial resistance. Common examples include ciprofloxacin and levofloxacin.
2. Folate antagonists are antibiotics that inhibit bacterial folate synthesis. This includes sulfonamides, which block de novo folate synthesis, and trimethoprim, which prevents conversion of dihydrofolic acid to tetrahydrofolic acid.
3. Urinary tract antiseptics are briefly mentioned but not described.
Ciprofloxacin is a synthetic broad spectrum fluoroquinolone antibiotic that binds to and inhibits bacterial DNA gyrase, an enzyme essential for DNA replication. It is more active against Gram-negative bacteria. Ciprofloxacin lactate is manufactured by condensing Fluoroquinolonic Acid with piperazine and other compounds, then treating it with lactic acid to form Ciprofloxacin Lactate. The global market for ciprofloxacin hcl is growing due to its increasing use to treat infections in the urogenital, respiratory, and gastrointestinal systems as well as typhoid, bone and joint infections, and more.
This document discusses beta-lactam antibiotics, including penicillins. It describes how penicillins work by inhibiting bacterial cell wall synthesis through binding to penicillin-binding proteins. This prevents cross-linking of peptidoglycan and kills bacteria. It classifies penicillins as narrow spectrum (natural penicillins) or broad spectrum (aminopenicillins, antipseudomonal penicillins). Common adverse effects include allergic reactions and disruption of normal gut flora. Resistance can develop through plasmids transferring resistance genes.
- 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
Quinolones were first developed in the 1960s and can be classified into generations based on their antimicrobial activity. First generation quinolones were active against gram-negative bacteria but not Pseudomonas. Later generations showed increased activity against gram-positive pathogens and mycobacteria. Quinolones act by inhibiting bacterial DNA gyrase and topoisomerase IV, blocking DNA synthesis. They are potent against a variety of bacteria including E. coli, Salmonella, and Staphylococcus. However, resistance may develop via mutations in genes encoding DNA gyrase/topoisomerase IV or active drug transport.
This document discusses cephalosporins, a class of beta-lactam antibiotics. It describes their mechanism of action as inhibiting transpeptidases called penicillin binding proteins, disrupting the synthesis of bacterial cell walls. Cephalosporins are divided into five generations based on their spectrum of activity and resistance to beta-lactamases. Each newer generation has increased activity against gram-negative rods and decreased activity against gram-positive cocci. The document provides examples of therapeutic uses, dosages, and adverse effects for each generation of cephalosporins. It highlights that the fifth generation cephalosporin ceftarolinefosamil was approved in 2010 and is effective against methicillin
Antibiotics inhibiting protein synthesis 3 chloramphenicol and macrolides 03 ...Ravi Kant Agrawal
1. Chloramphenicol and macrolides like erythromycin inhibit protein synthesis in bacteria by binding to the 50S subunit of the bacterial ribosome, preventing proper alignment and peptide bond formation.
2. Chloramphenicol has broad-spectrum activity but is limited in clinical use due to potential bone marrow toxicity. It maintains activity against many gram-positive and gram-negative bacteria as well as some anaerobes.
3. Macrolides bind tightly to the P site of the bacterial ribosome, blocking translocation and translation. They are effective against a variety of bacteria and atypical pathogens.
Chloramphenicol is an antibiotic produced by Streptomyces venezuelae. It inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit, preventing binding of aminoacyl tRNA and inhibiting peptide bond formation. It can also inhibit mitochondrial protein synthesis. Chloramphenicol is administered orally or intravenously and is well absorbed. It is indicated for serious infections such as meningitis or typhoid fever. However, it carries risks of bone marrow suppression and aplastic anemia.
Chloramphenicol Pharmacology-
Topics covered:-
1. Introduction
2. Structure
3. Mechanism Of Action
4. Bacterial Resistance to Chloramphenicol
5. Antimicrobial Spectrum
6. Pharmacokinetics
7. Adverse Effects
8. Drug Interactions
9. Therapeutic Uses
Chloramphenicol, a potent and versatile antibiotic, has played a significant role in the field of medicine since its discovery in the late 1940s. This broad-spectrum antibiotic is highly effective against a wide range of bacteria, making it a valuable tool in the fight against infectious diseases. However, its history is marked by controversies and challenges, which have influenced its usage and regulation.
Chloramphenicol was first isolated from the bacterium Streptomyces venezuelae in 1947, marking a significant milestone in the development of antibiotics. Its ability to inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit distinguishes it as a bacteriostatic agent. This mode of action makes chloramphenicol effective against various Gram-positive and Gram-negative bacteria, including some drug-resistant strains.
Despite its efficacy, chloramphenicol's history is marred by concerns about its safety. In the 1950s and 1960s, it was widely used as a broad-spectrum antibiotic for various infections. However, it was later associated with a potentially life-threatening condition known as "gray baby syndrome" in neonates, leading to restrictions on its use in children and pregnant women. Additionally, it has been linked to aplastic anemia, a rare but serious side effect, which led to further restrictions on its use in many countries.
The complex history of chloramphenicol extends to its current status in the medical field. While it is still used in some cases, it is typically reserved for situations where other antibiotics have failed, and safer alternatives are unavailable. The availability and regulation of chloramphenicol vary from country to country due to these concerns.
In recent years, research has focused on understanding the molecular mechanisms of chloramphenicol's action and the development of more targeted antibiotics with improved safety profiles. Its unique characteristics and historical significance continue to make it a subject of interest in the ongoing battle against bacterial infections.
In conclusion, chloramphenicol is a potent broad-spectrum antibiotic with a rich and complex history. Its discovery revolutionized the treatment of infectious diseases, but safety concerns have led to restricted use. Ongoing research seeks to balance its efficacy with safety, highlighting the ongoing importance of this antibiotic in the field of medicine.
Chloramphenicol is an antibiotic produced by Streptomyces venezuelae that was first isolated in 1947. It inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit, preventing peptide bond formation. While effective against a variety of bacteria, chloramphenicol can also inhibit mitochondrial protein synthesis in mammalian cells, causing toxicity issues like bone marrow suppression and the rare but serious gray baby syndrome in neonates. As such, it is reserved for treating serious infections when other antibiotics cannot be used.
This document discusses various topics related to antimicrobial agents including classification, mechanisms of action, uses, and adverse effects. It describes different classes of antibiotics such as beta-lactams, sulfonamides, fluoroquinolones, and their characteristics. It provides information on classification based on source and mechanism of action. Common uses and adverse effects of these antibiotics are also summarized. The document also includes several multiple choice questions related to antimicrobial therapy.
The document discusses fluoroquinolone antibiotics including their mechanism of action, categories, spectrum of activity, and adverse effects. It notes that ciprofloxacin is effective against many gram-negative bacteria and atypical pathogens. Newer fluoroquinolones like levofloxacin and moxifloxacin have expanded activity against some gram-positive bacteria. Common adverse effects include gastrointestinal issues and central nervous system problems. Prolonged use may cause tendon damage or arrhythmias. The document also covers how sulfonamides and trimethoprim work by inhibiting bacterial folate synthesis.
Chloramphenicol is a broad-spectrum antibiotic that was first obtained from Streptomyces venezuelae in 1947. It inhibits bacterial protein synthesis by interfering with the transfer of the elongating peptide chain during translation at the ribosome. Chloramphenicol is active against both gram-positive and gram-negative bacteria. While it is effective orally and inexpensive, extensive use led to high resistance among many bacteria. Chloramphenicol can cause serious bone marrow toxicity like aplastic anemia and is not recommended for minor infections. It requires careful dosage monitoring, especially in newborns, to avoid the potentially lethal "gray baby syndrome."
This document discusses two broad-spectrum antibiotics - tetracycline and chloramphenicol. It provides details on their structure, mechanisms of action, pharmacokinetics, antimicrobial spectrum, resistance, clinical uses and doses, contraindications, and adverse effects. Tetracycline is obtained from soil actinomycetes and has a four-cyclic-anthracyclin ring structure. It inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. Chloramphenicol is a naturally occurring antibiotic isolated from Streptomyces venezuelae that possesses a nitro group and inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. Both antibiotics have become less used due to increasing bacterial resistance.
This document discusses the antibiotic chloramphenicol. It begins by stating that chloramphenicol is isolated from Streptomyces cultures and inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. It has broad-spectrum activity against gram-positive and gram-negative bacteria as well as rickettsiae. Resistance is caused by plasmid-mediated chloramphenicol acetyltransferase. It is absorbed rapidly after oral administration, widely distributed in tissues, and metabolized in the liver. While it can treat serious infections, it carries risks like bone marrow suppression and grey baby syndrome in newborns.
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.
Quinolones and Fluoroquinolone MOA,ADME,Spectrum of activity of Quinolones.FahimAnwarRizwi
This document provides an overview of quinolones, including their mechanism of action, therapeutic uses, and adverse effects. Key points:
- Quinolones target bacterial DNA gyrase and topoisomerase IV, inhibiting their activity and blocking bacterial DNA synthesis.
- They have broad-spectrum activity against many gram-positive and gram-negative bacteria. Common therapeutic uses include UTIs, respiratory infections, and abdominal/GI infections.
- While generally well-absorbed and effective, quinolones can cause gastrointestinal side effects and tendon/joint problems. Neurological and phototoxic adverse reactions led to the withdrawal of some quinolones from the market.
This document discusses two classes of protein synthesis inhibitors - tetracyclines and chloramphenicol. It provides details on their mechanisms of action, classifications, spectra of activity, pharmacokinetics, clinical uses, resistance, side effects and interactions. Tetracyclines are classified based on source and duration of action. They inhibit bacterial protein synthesis by binding to the 30S ribosomal subunit. Chloramphenicol also inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. Both classes have broad-spectrum activity and are associated with various side effects.
This document provides an overview of quinolones and fluoroquinolones antibiotics. It discusses their mechanism of action, spectrum, dosage, side effects and interactions. Specific drugs like ciprofloxacin, norfloxacin and levofloxacin are explained in detail. The uses of fluoroquinolones in treating various infections like UTIs, sexually transmitted diseases, respiratory infections and travelers diarrhea are outlined. Practical tips for administration and a rapid review with self-test questions are also provided.
The document summarizes key information about the phenicol class of antibiotics. It describes the discovery and production of chloramphenicol as the first broad-spectrum phenicol antibiotic. It discusses the absorption, distribution, metabolism and excretion of chloramphenicol and other phenicols like florfenicol and thiamphenicol. The mechanism of action involves binding to the bacterial ribosome. Phenicols are used to treat various infections in animals and humans, though chloramphenicol use is restricted in food animals due to human health concerns. Bacteria can develop resistance through several mechanisms.
This document discusses various protein synthesis inhibitors including tetracyclines, chloramphenicol, and macrolides. It provides details on their mechanisms of action, pharmacokinetics, clinical uses, and resistance. Tetracyclines like doxycycline are bacteriostatic and bind to the 30S ribosomal subunit. Chloramphenicol inhibits bacterial protein synthesis by interfering with peptide bond formation. Macrolides like erythromycin bind to the 50S ribosomal subunit and inhibit translocation. These antibiotics are used for treating various bacterial infections.
Chloramphenicol was the first antibiotic to be manufactured synthetically for clinical use. It inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. While broad-spectrum, it carries risks of bone marrow toxicity in humans. Safer derivatives like thiamphenicol and florfenicol were later developed.
Chloramphenicol is a broad-spectrum antibiotic produced by Streptomyces venezuele that was introduced in 1948. It works by binding to the 50s ribosomal subunit and inhibiting protein synthesis in bacteria. However, it can also interfere with mitochondrial protein synthesis in mammalian cells, causing serious and potentially fatal blood disorders. For this reason, chloramphenicol is now reserved for life-threatening infections like meningitis or rickettsial infections when safer alternatives cannot be used due to resistance or allergies. While effective against a wide range of bacteria, chloramphenicol's use is limited by its risk of toxicities like aplastic anemia and gray baby syndrome in neonates.
This document discusses chloramphenicol, an antibiotic produced by Streptomyces venezuelae. It was the first antibiotic manufactured synthetically on a large scale. Chloramphenicol inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit, preventing peptide bond formation. It is absorbed orally and distributed widely throughout the body. While effective against many infections, it can cause potentially fatal bone marrow suppression and aplastic anemia. As a result, chloramphenicol is reserved for serious infections where other antibiotics cannot be used.
Fluoroquinolones are a class of broad-spectrum antibiotics that include ciprofloxacin, moxifloxacin, and norfloxacin. They work by inhibiting bacterial DNA synthesis through effects on DNA gyrase and topoisomerase IV. Ciprofloxacin is an example that is administered orally or intravenously to treat various bacterial infections. However, bacterial resistance to fluoroquinolones has been increasing worldwide. Ciprofloxacin specifically has good oral absorption and bioavailability but can interact with various other drugs if not taken correctly. It is also important to monitor for potential side effects like gastrointestinal issues, rashes, and neurotoxicity with ciprofloxacin use.
This document provides an overview of quinolones, a class of antibacterial agents. It discusses the discovery of nalidixic acid, the first quinolone, and the subsequent development of fluoroquinolones. The mechanisms of action and mechanisms of resistance are described. Various generations of fluoroquinolones are classified and their spectra of activity, pharmacokinetics, uses, and adverse effects are summarized. Newer quinolone agents such as finalafloxacin and delafloxacin are also briefly mentioned.
This presentation discusses Contoso's goals for the next quarter, including synergizing scalable e-commerce, disseminating standardized metrics, coordinating e-business applications, and deploying strategic networks. The presentation outlines Contoso's areas of growth in B2B supply chain, ROI, and e-commerce. It then provides a timeline for the product launch plan and areas of focus on B2B market scenarios and cloud-based opportunities.
This PowerPoint presentation covers various topics and includes an agenda, introduction, topic one with a chart and table, quotes, a team page, timeline, tips on using PowerPoint, and a concluding thank you slide. The presentation teaches how to create and share presentations using PowerPoint across devices by adding text, images, videos and saving to OneDrive for access on a computer, tablet or phone.
The document contains an agenda for a presentation with topics on charts and tables showing various data, quotes on getting started, and sections on the team, timeline, and how to use presentation features in PowerPoint like starting the slide show, presenter view, notes pane, and navigating between slides. It concludes with a summary and thank you.
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2. Introduction
•Chloramphenicol is a broad-spectrum
antibiotic.
•Chloramphenicol is a bacteriostatic antimicrobial
•With the drug's wide use, it became evident
that chloramphenicol could cause serious and
fatal blood dyscrasias. For this reason,
chloramphenicol is now reserved for treatment
of life-threatening infections (e.g., meningitis,
rickettsial infections) in patients who cannot take
safer alternatives because of resistance or
allergies
3. Source
• Originally derived from the bacterium
called Streptomyces Venezuelae,
isolated by David Gottlieb,in 1947.
• But nowa days it is produced
synthetically.
4. Description:
Chloramphenicol is a white crystalline compound
that is soluble in alcohal but slightly soluble in
water and it is bitter in taste. So sometimes we need to
increase its solubility when it is intended to be
administered by IV route and sometimes we need to
mask its taste when it administered in the form of
suspension. Thus chloramphenicol palmitate is
Tasteless but insoluble in water and is used in
suspension while chloramphenicol succinate is soluble
in water but bitter in taste and is used for injections.
5.
6.
7. PK
The usual dosage of chloramphenicol is 50-100
mg/kg/d. Chloramphenicol palmitate is a prodrug that
is hydrolyzed in the intestine to yield free
chloramphenicol. The parenteral formulation is a
prodrug, chloramphenicol succinate, which hydrolyzes
to yield free chloramphenicol, giving blood levels
somewhat lower than those achieved with orally
administered drug. Chloramphenicol is widely
distributed to virtually all tissues and body fluids,
including the central nervous system and cerebrospinal
fluid, such that the concentration of chloramphenicol
in brain tissue may be equal to that in serum.
9. The drug penetrates cell membranes readily.
Most of the drug is inactivated either by conjugation
with glucuronic acid (principally in the liver) or by
reduction to inactive aryl amines. Active
chloramphenicol (about 10% of the total dose
administered) and its inactive degradation products
(about 90% of the total) are eliminated in the urine. A
small amount of active drug is excreted into bile and
feces. The systemic dosage of chloramphenicol need
not be altered in renal insufficiency, but it must be
reduced markedly in hepatic failure. Newborns less
than a week old and premature infants also clear
10. chloramphenicol less well, and the dosage should be
reduced to 25 mg/kg/d.
N)
Parenteral administration of Chloramphenicol is
generally reserved for situations in which oral therapy
is contraindicated, as in the treatment of meningitis
and septicemia or when vomiting prohibits oral
administration.
11. Antimicrobial Spectrum:
Chloramphenicol is a bacteriostatic broad-spectrum
antibiotic that is active against both aerobic and
anaerobic gram-positive and gram-negative organisms.
It is active also against rickettsiae but not chlamydiae.
H influenzae, S. Typhi, N meningitidis, and some
strains of bacteroides are highly susceptible.
It is not active against Pseudomonas aeruginosa or
Enterobacter species.
13. Therapeutic Uses
Therapy with chloramphenicol must be
limited to infections for which the benefits of
the drug outweigh the risks of the potential
toxicities. When other antimicrobial drugs
are available that are equally effective and
potentially less toxic than chloramphenicol,
they should be used
14. Chloramphenicol has a wide range
activity that includes gram+, gram-
, aerobic and anaerobic bacteria
Typhoid Fever
Bacterial Meningitis
Anaerobic Infections
Rickettsial Diseases
Brucellosis
15. Chloramphenicol
Clinical uses
Limited because of potential toxicities
(a plastic anaemia &)
1. Typhoid fever- s. typhi ( quinolones are
preffered)
2. Meningitis –
H.influenzae,N.meningitidis,S.pneumoniae
( Ceftriaxone is preffered )
3. Anaerobic infections- B. fragilis
(Metronidazole is the drug
of choice)
4. Rickettsial infections – Doxycycline is preffered
5. Bacterial conjunctivitis ( topical )
16.
17. Exp
Cloramphenicol is not DOC b/c of its adverse effects,
bacterial resistance and availability of better agents.
1.Chloramphenicol is very effective against
H.influenzae meningitis. It is an alternative to a β
lactam antibiotic for treatment of meningococcal
meningitis occurring in patients who have major
hypersensitivity reactions to penicillin or bacterial
meningitis caused by penicillin resistant strains of
pneumococci. The dosage is 50-100 mg/kg/d in four
divided doses.
2. Severe rickettsial infections
18. 3. As drops or ointment, it is used for eye or ear
infections.
4. Chloramphenicol was the DOC for enteric fever but
now it is on reserve list due to availability of safer
drugs (Ciprofloxacin).
5. Since effective CSF levels are obtained, it used
to be a choice for treatment of specific bacterial causes
of meningitis: Haemophilus influenzae, Neisseria
meningitidis, and Strepcoccus pneumoniae.
19. Mechanism of Action
Chloramphenicol inhibits protein synthesis in
bacteria and, to a lesser extent, in eukaryotic cells.
The drug readily penetrates bacterial cells, probably
by facilitated diffusion.
20. Chloramphenicol is a potent inhibitor of microbial
protein synthesis. It binds reversibly to the 50S subunit
of the bacterial ribosome and inhibits the peptidyl
transferase thus inhibiting the peptide bond formation
b/w peptide chain at P site and amino acid at site A
(protein synthesis)
21. Fig.
Steps in bacterial protein synthesis and targets of
several antibiotics. Amino acids are shown as
numbered circles. The 70S ribosomal mRNA complex
is shown with its 50S and 30S subunits. In step 1, the
charged tRNA unit carrying amino acid 8 binds to the
acceptor site A on the 70S ribosome. The peptidyl
tRNA at the donor site, with amino acids 1 through 7,
then binds the growing amino acid chain to amino acid
8 (transpeptidation, step 2). The uncharged tRNA left
at the donor site is released (step 3), and the new
22. 8-amino acid chain with its tRNA shifts to
the peptidyl site (translocation, step 4). The antibiotic
binding sites are shown schematically as triangles.
Chloramphenicol (C) and macrolides (M) bind to the
50S subunit and block transpeptidation (step 2). The
tetracyclines (T) bind to the 30S subunit and prevent
binding of the incoming charged tRNA unit (step 1).
Note
Chloramphenicol and the macrolide class of
antibiotics both interact with the 50S ribosomal
subunit, chloramphenicol is not a macrolide.
Furthermore, their mechanisms are slightly different.
While chloramphenicol directly interferes with
substrate binding, macrolides sterically block the progression of the growing
peptide
23. MOA (S) (I)
It acts by inhibiting protein synthesis in bacteria by
binding reversibly to 50 S subunit and preventing the
binding of amino aceyl tRNA to the acceptor site on
the 50 S subunit. It interferes with the interaction b/w
peptidyl transferase and amino acid, thereby
preventing peptide bond formation.
24. MOA (L) (i)
Chloramphenicol (Chloromycetin) is a nitrobenzene
derivative that affects protein synthesis by binding to
the 50S ribosomal subunit and preventing peptide
Bond formation. It prevents the attachment of the
amino acid end of aminoacyl-tRNA to the A site,
hence the association of peptidyltransferase with the
amino acid substrate.
25. Resistance:
Bacterial ribosome develops resistance to
chloramphenicol either
1.Decreasing its permeability into the bacterial cell.
2.Inactivation of the drug by acetyl transferase enzyme
produced by resistant organisms which causes
acetylation at 1 and 3 positions.
26. Interaction with other drugs
Chloramphenicol inhibits hepatic microsomal
enzymes that metabolize several drugs. Half-lives are
prolonged, and the serum concentrations of phenytoin,
tolbutamide, chlorpropamide, Cyclophosphamide and
warfarin are increased. Some drugs like chronic administration of
phenobarbitone or acute administration of rifampicin
may increase the elimination of chloramphenicol by
enzyme induction. Like other bacteriostatic inhibitors
of microbial protein synthesis, chloramphenicol can antagonize
bactericidal drugs such as penicillins or aminoglycosides.
28. Adverse Reactions----------------------------------
1. Gastrointestinal disturbances
These include Nausea, vomiting, and diarrhea. The
chances of intestinal superinfection (unlike
tetracycline) are rare b/c it is completely absorbed
from GIT.
2. Bone marrow depression (Aplastic anemia) when
used for 1-2 weeks or more.
3. Toxicity for newborn infants (Neonates)
Newborn infants lack an effective glucuronic acid
conjugation mechanism for the degradation and
29. detoxification of chloramphenicol. Consequently,
when infants are given dosages above 50 mg/kg/d, the
drug may accumulate, resulting in the gray baby
syndrome, with vomiting, flaccidity, hypothermia,
gray color, shock, and collapse. To avoid this toxic
effect, chloramphenicol should be used with caution in
infants and the dosage limited to 50 mg/kg/d or less
(during the first week of life) in full-term infants more
than 1 week old and 25 mg/kg/d in premature infants.
30. Toxicity in neonates;
If neonates, specially premature babies, are exposed to
75mg/kg/day or more more of chloramphenicol,
chloramphenicol toxicity, commonly called gray baby
syndrome may develop wihin two to three days of
administration of the drug.It starts with vomiting,
refusal to suck, irregular and rapid respiration,
abdominal distension, periods of cynosis, with loose
green stool. Within another twenty four hours they
become flaccid, develop hypothermia and turns ashes
gray. Metabolic acidosis may appear and death occurs
in 40% of the patients.
31. The mechanisms responsible for he gray syndrome are
1.Failure of the drug to be conjugated with glucuronic
acid due to in adequate activity of glucuronyl
transferase in the liver in the neonate period
2.Inadequate renal excretion of unconjugated drug in
neonate.
32. Preparations available:
1. Chloromax by Pharmedic
Inj. 1 gm chloramphenicol (As sodium succinate)
2. Chloromycetin by parke-Davis/Pfizer
Cap- 250 mg Chloramphenicol base
Susp: Per 5 mL: Chloramphenicol palmitate equiv. to
125 mg chloramphenicol base.
3. Neo-Phenicol by PDH
Susp: Per 5 mL: Chloramphenicol palmitate equiv. to
125 mg chloramphenicol base.
33. Dosage (I)
The usual dose is 50 mg/kg/day in four divided doses:
the usual dose in an adult male is therefore around
750 mg four times daily; this dose is doubled in severe
illness. Half the dose is used in premature babies or
neonates, because they do not metabolise the drug as
effectively.
chloramphenicol is sold as chloramphenicol palmitate
ester. Chloramphenicol palmitate ester is inactive, and
is hydrolysed to active chloramphenicol in the small
intestine. There is no difference in bioavailability
between chloramphenicol and chloramphenicol
34. palmitate.
The intravenous (IV) preparation of chloramphenicol
is the succinate ester, because pure chloramphenicol
does not dissolve in water. This creates a problem:
chloramphenicol succinate ester is an inactive prodrug
and must first be hydrolysed to chloramphenicol; the
hydrolysis process is incomplete and 30% of the dose
is lost unchanged in the urine, therefore serum
concentrations of chloramphenicol are only 70% of
those achieved when chloramphenicol is given orally.
For this reason, the chloramphenicol dose needs to be
increased to 75 mg/kg/day when administered IV in
35. order to achieve levels equivalent to the oral dose. The
oral route is therefore preferred to the intravenous
route.
Chloramphenicol and the liver
Chloramphenicol is metabolised by the liver to
chloramphenicol glucuronate (which is inactive). In
liver impairment, the dose of chloramphenicol must
therefore be reduced. There is no standard dose
reduction for chloramphenicol in liver impairment,
and the dose should be adjusted according to measured
plasma concentrations. Chloramphenicol is also noted
for its cause of "Gray Baby Syndrome" because of infants lack of the enzyme
glucoronyl transferase
which is the main pathway.
36. Clinical features
Toxic levels of chloramphenicol after 2–9 days result
in:
1.Vomiting
2. Ashen gray color of the skin
3. Limp body tone
4. Hypotension (low blood pressure)
5. Cyanosis blue discolouration of lips and skin.
5. Hypothermia
6. Cardiovascular collapse
37. Treatment
Chloramphenicol therapy is discontinued immediately;
exchange transfusion may be required to remove the
drug.
Prevention
The condition can be prevented by using
chloramphenicol at the recommended doses and
monitoring blood levels, or alternatively, third
generation cephalosporins can be effectively
substituted for the drug, without the associated toxicity
38. Cynosis:
Bluish coloration of the skin due to low level of
oxygen in blood.
Hemolytic anemia:
It is characterized by rupture of RBC’s.
Agranulocytosis:
Decrease in no. of granulocytes.
Pancytopenia
The decrease in the number of RBC’s , WBCs and
Platelets.