Antibiotics and antimicrobial agents can be classified based on their chemical structure, mechanism of action, spectrum of activity, and source. Beta-lactams like penicillins, cephalosporins, carbapenems, and monobactams as well as glycopeptides inhibit bacterial cell wall synthesis. Aminoglycosides, macrolides, lincosamides, streptogramins, tetracyclines, phenicols, and oxazolidinones inhibit protein synthesis in bacteria. Odontogenic infections are usually mixed aerobic-anaerobic infections involving streptococci and require broad spectrum antibiotics like amoxicillin that cover both gram-positive and gram-negative organisms
Sulfonamide (also called sulphonamide, sulfa drugs or sulpha drugs) is the basis of several groups of drugs. The original antibacterial sulfonamides are synthetic antimicrobial agents that contain the sulfonamide group.
Respiratory stimulants are drugs that stimulate respiration and can restore consciousness in coma or fainting. They work by directly activating the respiratory center or through reflex action. At low doses, they stimulate respiration, but the margin of safety is narrow, and high doses can cause convulsions. Their role in therapeutics is limited, as they may be used in conditions like overdose with sedatives until mechanical ventilation, suffocation from drowning, or respiratory depression after anesthesia or in premature infants. Respiratory stimulants are classified as those acting directly on the respiratory center, those acting through reflex action, or those with mixed mechanisms of action. Doxapram, for example, promotes excitation of central neurons controlling
This document discusses amoebiasis, also known as amoebic dysentery, which is an intestinal infection caused by the protozoan Entamoeba histolytica. It is transmitted through contaminated food, water, or feces and causes symptoms ranging from mild diarrhea to severe dysentery. Drugs used to treat amoebiasis are classified as luminal, systemic, or mixed depending on where in the body they act. Metronidazole is a commonly used mixed amebicide that kills E. histolytica trophozoites throughout the body. It is activated by anaerobic bacteria and damages parasite DNA. Other discussed drugs include chloroquine for liver abscesses and
Aminoglycosides are a class of antibiotics that are produced by soil bacteria. They are primarily used to treat infections caused by aerobic gram-negative bacteria and some are used for mycobacterial infections. Aminoglycosides work by binding to bacterial ribosomes which interferes with protein synthesis. They have concentration-dependent bactericidal activity against many gram-negative organisms but limited activity against gram-positive bacteria. Common adverse effects include ototoxicity and nephrotoxicity. Therapeutic drug monitoring is important when using aminoglycosides to minimize toxicity risks.
ANTI-TB AND ANTI LEPROTIC DRUGS [MEDICINAL CHEMISTRY] BY P.RAVISANKAR.Dr. Ravi Sankar
This document provides information about anti-tubercular drugs. It discusses various drugs used to treat tuberculosis (TB) including isoniazid, rifampicin, ethambutol, and pyrazinamide. It describes the mechanisms of action, side effects, dosages, and importance of combination therapy to prevent development of drug resistance in TB treatment.
The document discusses expectorants and antitussives. It defines expectorants as drugs that increase bronchial secretion or reduce viscosity, facilitating removal by coughing. Only guaiphenesin is approved as an expectorant in the U.S. Expectorants are classified as bronchial secretion enhancers or mucolytics. Antitussives act in the CNS to suppress cough or act peripherally in the respiratory tract. Antitussives are classified as opioids, nonopioids, antihistamines, or peripherally acting drugs. The document provides examples and doses of expectorants and antitussives and discusses some combination antitussive-expectorant formulations.
This document provides an overview of cephalosporins, a class of beta-lactam antibiotics. It describes their classification into four generations based on their spectrum of activity and other properties. Key points include: Cephalosporins are derived from the fungus Cephalosporium and are bactericidal by inhibiting bacterial cell wall synthesis. Their classification is based on their spectrum of activity, with later generations having increased activity against gram-negative bacteria. Common examples from each generation like cefazolin, cefuroxime, cefotaxime, and cefepime are described along with their indications, dosages, and adverse effects.
Sulfonamide (also called sulphonamide, sulfa drugs or sulpha drugs) is the basis of several groups of drugs. The original antibacterial sulfonamides are synthetic antimicrobial agents that contain the sulfonamide group.
Respiratory stimulants are drugs that stimulate respiration and can restore consciousness in coma or fainting. They work by directly activating the respiratory center or through reflex action. At low doses, they stimulate respiration, but the margin of safety is narrow, and high doses can cause convulsions. Their role in therapeutics is limited, as they may be used in conditions like overdose with sedatives until mechanical ventilation, suffocation from drowning, or respiratory depression after anesthesia or in premature infants. Respiratory stimulants are classified as those acting directly on the respiratory center, those acting through reflex action, or those with mixed mechanisms of action. Doxapram, for example, promotes excitation of central neurons controlling
This document discusses amoebiasis, also known as amoebic dysentery, which is an intestinal infection caused by the protozoan Entamoeba histolytica. It is transmitted through contaminated food, water, or feces and causes symptoms ranging from mild diarrhea to severe dysentery. Drugs used to treat amoebiasis are classified as luminal, systemic, or mixed depending on where in the body they act. Metronidazole is a commonly used mixed amebicide that kills E. histolytica trophozoites throughout the body. It is activated by anaerobic bacteria and damages parasite DNA. Other discussed drugs include chloroquine for liver abscesses and
Aminoglycosides are a class of antibiotics that are produced by soil bacteria. They are primarily used to treat infections caused by aerobic gram-negative bacteria and some are used for mycobacterial infections. Aminoglycosides work by binding to bacterial ribosomes which interferes with protein synthesis. They have concentration-dependent bactericidal activity against many gram-negative organisms but limited activity against gram-positive bacteria. Common adverse effects include ototoxicity and nephrotoxicity. Therapeutic drug monitoring is important when using aminoglycosides to minimize toxicity risks.
ANTI-TB AND ANTI LEPROTIC DRUGS [MEDICINAL CHEMISTRY] BY P.RAVISANKAR.Dr. Ravi Sankar
This document provides information about anti-tubercular drugs. It discusses various drugs used to treat tuberculosis (TB) including isoniazid, rifampicin, ethambutol, and pyrazinamide. It describes the mechanisms of action, side effects, dosages, and importance of combination therapy to prevent development of drug resistance in TB treatment.
The document discusses expectorants and antitussives. It defines expectorants as drugs that increase bronchial secretion or reduce viscosity, facilitating removal by coughing. Only guaiphenesin is approved as an expectorant in the U.S. Expectorants are classified as bronchial secretion enhancers or mucolytics. Antitussives act in the CNS to suppress cough or act peripherally in the respiratory tract. Antitussives are classified as opioids, nonopioids, antihistamines, or peripherally acting drugs. The document provides examples and doses of expectorants and antitussives and discusses some combination antitussive-expectorant formulations.
This document provides an overview of cephalosporins, a class of beta-lactam antibiotics. It describes their classification into four generations based on their spectrum of activity and other properties. Key points include: Cephalosporins are derived from the fungus Cephalosporium and are bactericidal by inhibiting bacterial cell wall synthesis. Their classification is based on their spectrum of activity, with later generations having increased activity against gram-negative bacteria. Common examples from each generation like cefazolin, cefuroxime, cefotaxime, and cefepime are described along with their indications, dosages, and adverse effects.
This document discusses the anti-tuberculosis drug ethionamide. It is a second-line drug that is an analogue of isonicotinamide but contains sulfur instead of oxygen. It is less active in vitro but more active in vivo due to increased lipophilicity from its ethyl group. Its mechanism of action involves conversion to its active metabolite ethionamide sulfoxide via oxidation, which then inactivates the inhA enoyl reductase enzyme. Less than 1% is excreted unchanged in urine with the rest excreted as metabolites.
Isoniazid, Rifampicin, Pyrazinamide and EthambutolFahad Ullah
This document provides information on anti-tubercular drugs used to treat tuberculosis. It discusses the first and second line drugs, including isoniazid, rifampicin, pyrazinamide, and ethambutol. For each drug, it describes the mechanism of action, synthesis, structure-activity relationships, side effects, dosing, and brands. The recommended treatment regimen for tuberculosis is a combination of drugs over 6 months, with an intensive initial phase using multiple first line drugs, followed by a continuation phase typically using rifampin and isoniazid.
The document summarizes the quinolones, a class of synthetic antibacterial agents. It describes their history, chemistry, generations, mechanisms of action, resistance, pharmacokinetics, clinical uses, drug interactions, and adverse effects. Quinolones work by inhibiting bacterial DNA gyrase and topoisomerase enzymes. Later generations have broader spectra of activity against both gram-positive and gram-negative bacteria. Common side effects include nausea and potential cartilage damage in children.
This document discusses local anti-infective agents and was presented by Swathi Kencha from Bangalore. It defines antiseptics as chemicals that kill or prevent growth of microorganisms on living tissue, and disinfectants as preventing transmission of infection on inanimate objects. Common local anti-infective agents are discussed, including alcohols, phenols, oxidizing agents, halogens, surfactants, dyes, nitrofurans, and mercury compounds. Their ideal properties and mechanisms of action are described.
This document discusses sulfonamides, which were the first effective chemotherapeutic agents used to treat bacterial infections. Sulfonamides work by inhibiting the bacterial synthesis of folic acid, which is essential for bacterial growth. They do this by competing with para-amino benzoic acid (PABA) for the folic acid synthetase enzyme. Common side effects include bone marrow suppression, allergic reactions, and crystalluria. Sulfonamides are often used in combination with other drugs to treat infections like typhoid, UTIs, and meningococcal meningitis.
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.
This document provides an overview of asthma, including its definition, characteristics, classification, pathophysiology, symptoms, diagnosis, treatment approaches, and medications. Asthma is defined as a chronic inflammatory airway disorder characterized by bronchial hyperresponsiveness and reversible airway obstruction. It is classified as extrinsic, intrinsic, or mixed. Diagnosis involves assessing history, symptoms, and lung function tests. Treatment follows a stepwise approach starting with short-acting bronchodilators and inhaled corticosteroids, adding additional controllers as needed. Status asthmaticus refers to an acute, severe exacerbation unresponsive to usual treatment.
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.
Cephalosporins are a class of antibiotics derived from the fungus Cephalosporium acremonium. They were first isolated in 1948 and are chemically related to penicillins. There are several generations of cephalosporins that have been developed with expanded spectra of activity. First generation cephalosporins such as cefazolin and cephalexin are effective against gram-positive bacteria. Later generations have activity against more gram-negative bacteria with third generation drugs like cefotaxime and ceftriaxone used to treat serious infections. Cephalosporins are generally well-tolerated but can cause adverse effects like diarrhea, rash, bleeding and hypersensitivity reactions in some
synthetic antimicrobials having a quinolone structure that are active primarily against gram-negative bacteria, though newer fluorinated compounds also inhibit gram-positive ones.
Lincosamides are a class of antibiotics that include lincomycin, clindamycin, and pirlimycin. They are derived from the fermentation of Streptomyces bacteria and contain a sugar moiety linked to a pyrrolidine carboxylic acid. Clindamycin is a semi-synthetic derivative of lincomycin created by replacing the 7-hydroxy group with chlorine. Lincosamides inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit. They are primarily effective against Gram-positive bacteria and anaerobes but not most Gram-negatives.
The document discusses prodrugs, which are pharmacologically inactive derivatives of active drugs designed to improve drug properties like solubility, absorption, and site-specific delivery. It covers basic prodrug concepts and classifications like carrier-linked prodrugs and bioprecursors. Approaches for prodrug design include using carriers, linkers, and multi-drug systems. Applications of prodrugs include improving patient acceptability by modifying taste, odor or irritation, enhancing solubility and dissolution for better absorption, and enabling site-specific or sustained drug delivery. The document provides examples of prodrug linkages and enzymes involved in their hydrolysis.
Macrolides are a class of antibiotics derived from Saccharopolyspora erythraea (originally called Streptomyces erythreus), a type of soil-borne bacteria.
This document provides an overview of antineoplastic agents (chemotherapies) used to treat cancer. It begins by defining a neoplasm or tumor and describing the causes and types of cancer. It then discusses factors that affect cancer incidence and classifies antineoplastic drugs. The main classes described are alkylating agents, antimetabolites, antibiotics, plant products, and miscellaneous drugs. For each drug class and some individual drugs, the document provides details on mechanisms of action and specific uses to treat different cancer types. It concludes by covering the synthesis of some example antineoplastic agents including mechlorethamine, methotrexate, and mercaptopurine.
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.
1) Peptic ulcers are caused by an imbalance between aggressive factors like gastric acid and protective factors in the stomach and duodenum.
2) Anti-ulcer drugs work by decreasing gastric acid secretion, enhancing mucosal protection, or eradicating the H. pylori bacteria responsible for many ulcers.
3) Common classes of anti-ulcer medications include H2 receptor antagonists, proton pump inhibitors, antacids, and anti-H. pylori drugs. H2 receptor antagonists and proton pump inhibitors reduce acid by blocking histamine and the proton pump, while antacids neutralize existing acid.
Antibiotics are natural compounds produced by microorganisms that inhibit the growth of other microorganisms. They can be classified as bactericidal, killing bacteria, or bacteriostatic, preventing bacterial multiplication. Antibiotics exhibit selective toxicity by targeting microbes without harming host cells. Common mechanisms of action include inhibition of cell wall synthesis, alteration of cell membranes, inhibition of protein synthesis, and inhibition of nucleic acid synthesis.
Antimicrobials include antibacterials, antivirals, antifungals, and antiparasitic agents that inhibit or kill microorganisms. The document discusses various classes of antibiotics including their mechanisms of action and production sources. It describes how antibiotics can be bacteriostatic or bactericidal and covers antibiotic resistance mechanisms like changes to permeability, enzyme production, or target sites. Methods for determining antibiotic sensitivity are outlined, including disk diffusion assays and dilution tests to categorize organisms as resistant, intermediate, or sensitive.
This document discusses the anti-tuberculosis drug ethionamide. It is a second-line drug that is an analogue of isonicotinamide but contains sulfur instead of oxygen. It is less active in vitro but more active in vivo due to increased lipophilicity from its ethyl group. Its mechanism of action involves conversion to its active metabolite ethionamide sulfoxide via oxidation, which then inactivates the inhA enoyl reductase enzyme. Less than 1% is excreted unchanged in urine with the rest excreted as metabolites.
Isoniazid, Rifampicin, Pyrazinamide and EthambutolFahad Ullah
This document provides information on anti-tubercular drugs used to treat tuberculosis. It discusses the first and second line drugs, including isoniazid, rifampicin, pyrazinamide, and ethambutol. For each drug, it describes the mechanism of action, synthesis, structure-activity relationships, side effects, dosing, and brands. The recommended treatment regimen for tuberculosis is a combination of drugs over 6 months, with an intensive initial phase using multiple first line drugs, followed by a continuation phase typically using rifampin and isoniazid.
The document summarizes the quinolones, a class of synthetic antibacterial agents. It describes their history, chemistry, generations, mechanisms of action, resistance, pharmacokinetics, clinical uses, drug interactions, and adverse effects. Quinolones work by inhibiting bacterial DNA gyrase and topoisomerase enzymes. Later generations have broader spectra of activity against both gram-positive and gram-negative bacteria. Common side effects include nausea and potential cartilage damage in children.
This document discusses local anti-infective agents and was presented by Swathi Kencha from Bangalore. It defines antiseptics as chemicals that kill or prevent growth of microorganisms on living tissue, and disinfectants as preventing transmission of infection on inanimate objects. Common local anti-infective agents are discussed, including alcohols, phenols, oxidizing agents, halogens, surfactants, dyes, nitrofurans, and mercury compounds. Their ideal properties and mechanisms of action are described.
This document discusses sulfonamides, which were the first effective chemotherapeutic agents used to treat bacterial infections. Sulfonamides work by inhibiting the bacterial synthesis of folic acid, which is essential for bacterial growth. They do this by competing with para-amino benzoic acid (PABA) for the folic acid synthetase enzyme. Common side effects include bone marrow suppression, allergic reactions, and crystalluria. Sulfonamides are often used in combination with other drugs to treat infections like typhoid, UTIs, and meningococcal meningitis.
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.
This document provides an overview of asthma, including its definition, characteristics, classification, pathophysiology, symptoms, diagnosis, treatment approaches, and medications. Asthma is defined as a chronic inflammatory airway disorder characterized by bronchial hyperresponsiveness and reversible airway obstruction. It is classified as extrinsic, intrinsic, or mixed. Diagnosis involves assessing history, symptoms, and lung function tests. Treatment follows a stepwise approach starting with short-acting bronchodilators and inhaled corticosteroids, adding additional controllers as needed. Status asthmaticus refers to an acute, severe exacerbation unresponsive to usual treatment.
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.
Cephalosporins are a class of antibiotics derived from the fungus Cephalosporium acremonium. They were first isolated in 1948 and are chemically related to penicillins. There are several generations of cephalosporins that have been developed with expanded spectra of activity. First generation cephalosporins such as cefazolin and cephalexin are effective against gram-positive bacteria. Later generations have activity against more gram-negative bacteria with third generation drugs like cefotaxime and ceftriaxone used to treat serious infections. Cephalosporins are generally well-tolerated but can cause adverse effects like diarrhea, rash, bleeding and hypersensitivity reactions in some
synthetic antimicrobials having a quinolone structure that are active primarily against gram-negative bacteria, though newer fluorinated compounds also inhibit gram-positive ones.
Lincosamides are a class of antibiotics that include lincomycin, clindamycin, and pirlimycin. They are derived from the fermentation of Streptomyces bacteria and contain a sugar moiety linked to a pyrrolidine carboxylic acid. Clindamycin is a semi-synthetic derivative of lincomycin created by replacing the 7-hydroxy group with chlorine. Lincosamides inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit. They are primarily effective against Gram-positive bacteria and anaerobes but not most Gram-negatives.
The document discusses prodrugs, which are pharmacologically inactive derivatives of active drugs designed to improve drug properties like solubility, absorption, and site-specific delivery. It covers basic prodrug concepts and classifications like carrier-linked prodrugs and bioprecursors. Approaches for prodrug design include using carriers, linkers, and multi-drug systems. Applications of prodrugs include improving patient acceptability by modifying taste, odor or irritation, enhancing solubility and dissolution for better absorption, and enabling site-specific or sustained drug delivery. The document provides examples of prodrug linkages and enzymes involved in their hydrolysis.
Macrolides are a class of antibiotics derived from Saccharopolyspora erythraea (originally called Streptomyces erythreus), a type of soil-borne bacteria.
This document provides an overview of antineoplastic agents (chemotherapies) used to treat cancer. It begins by defining a neoplasm or tumor and describing the causes and types of cancer. It then discusses factors that affect cancer incidence and classifies antineoplastic drugs. The main classes described are alkylating agents, antimetabolites, antibiotics, plant products, and miscellaneous drugs. For each drug class and some individual drugs, the document provides details on mechanisms of action and specific uses to treat different cancer types. It concludes by covering the synthesis of some example antineoplastic agents including mechlorethamine, methotrexate, and mercaptopurine.
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.
1) Peptic ulcers are caused by an imbalance between aggressive factors like gastric acid and protective factors in the stomach and duodenum.
2) Anti-ulcer drugs work by decreasing gastric acid secretion, enhancing mucosal protection, or eradicating the H. pylori bacteria responsible for many ulcers.
3) Common classes of anti-ulcer medications include H2 receptor antagonists, proton pump inhibitors, antacids, and anti-H. pylori drugs. H2 receptor antagonists and proton pump inhibitors reduce acid by blocking histamine and the proton pump, while antacids neutralize existing acid.
Antibiotics are natural compounds produced by microorganisms that inhibit the growth of other microorganisms. They can be classified as bactericidal, killing bacteria, or bacteriostatic, preventing bacterial multiplication. Antibiotics exhibit selective toxicity by targeting microbes without harming host cells. Common mechanisms of action include inhibition of cell wall synthesis, alteration of cell membranes, inhibition of protein synthesis, and inhibition of nucleic acid synthesis.
Antimicrobials include antibacterials, antivirals, antifungals, and antiparasitic agents that inhibit or kill microorganisms. The document discusses various classes of antibiotics including their mechanisms of action and production sources. It describes how antibiotics can be bacteriostatic or bactericidal and covers antibiotic resistance mechanisms like changes to permeability, enzyme production, or target sites. Methods for determining antibiotic sensitivity are outlined, including disk diffusion assays and dilution tests to categorize organisms as resistant, intermediate, or sensitive.
This document provides information about different classes of antibiotics, including their mechanisms of action, examples within each class, and how bacteria can develop resistance. It discusses six classes: penicillins and cephalosporins which act on the bacterial cell wall; macrolides, aminoglycosides, tetracyclines, and others which inhibit bacterial protein synthesis; metronidazole and fluoroquinolones which act on bacterial DNA; and trimethoprim/sulfamethoxazole which inhibit bacterial folic acid synthesis. It also outlines several mechanisms by which bacteria develop resistance, such as genetic mutations, acquisition of resistance genes from other bacteria, and destruction or inactivation of antibiotics.
The document discusses various aspects of antimicrobial drugs and antibiotic resistance. It defines key terms like antimicrobials, antibiotics, and describes different classes of antibiotics including their mechanisms of action and examples. It discusses factors that influence the effectiveness of antibiotics like spectrum of activity, toxicity and resistance development. It differentiates between acquired and intrinsic antibiotic resistance, and lists factors like overuse/misuse of drugs, poor infection control and inappropriate antibiotic usage as major causes of acquired antibiotic resistance.
This document provides an overview of antimicrobials (also known as antibiotics). It defines antimicrobials and discusses their classification as bactericidal or bacteriostatic. The document outlines the history of antimicrobial discovery and discusses their sources, selective toxicity, and modes of action. Key topics covered include the classification of antibiotics based on chemical structure and mechanism of action, as well as details on specific classes of antibiotics like penicillins, cephalosporins, carbapenems, and others.
The document discusses antimicrobial agents and their properties and mechanisms of action. It defines antimicrobials as agents that kill or inhibit microorganisms with little host damage. Antimicrobials include antibiotics, which are low molecular substances produced by microorganisms that inhibit or kill other microorganisms. Antimicrobials act through various mechanisms including inhibiting cell wall synthesis, disrupting cell membranes, inhibiting protein synthesis, and interfering with nucleic acid synthesis. They can cause side effects like toxicity, allergies, and disruption of normal microflora. Microorganisms can develop resistance to antimicrobials through genetic or non-genetic changes.
1. The Kirbybauer method is a disc diffusion test used to determine antibiotic sensitivity. Filter paper discs loaded with antibiotics are placed on inoculated agar and allowed to diffuse. The zone of inhibition around each disc indicates sensitivity.
2. Antibiotics can inhibit bacterial cell wall, protein, or nucleic acid synthesis. Examples are penicillins blocking cell wall synthesis and rifampicin inhibiting bacterial transcription.
3. Antimicrobial resistance arises via mutations altering drug targets, enzymatic drug inactivation, or preventing drug uptake. It spreads between bacteria horizontally via plasmids encoding resistance genes. Prudent antibiotic use helps slow resistance development.
This document provides a summary of key points from a lecture on antibiotics and antimicrobial agents. It defines important terms like antibiotic, chemotherapy, and therapeutic index. It describes how antibiotics can be bactericidal or bacteriostatic. It also explains the mechanisms of action and classes of major antimicrobial agents that act on the cell wall, membrane, protein synthesis, or nucleic acids. Resistance mechanisms and principles of antimicrobial therapy are discussed.
Human: Thank you for the summary. Summarize the following document in 3 sentences or less:
[DOCUMENT]
Antibiotics are medications that fight bacterial infections. Some common types of antibiotics include penicillins, cephalosporins, and fluoroquinolones
Microbiology is the study of microorganisms.
The overall theme of the Microbiology course is to study the relationship between microbes and our lives.
Microorganisms (microbes) are organisms that are too small to be seen with the unaided eye, and usually require a microscope to be seen.
This relationship involves harmful effects such as diseases and food spoilage as well as many beneficial effects.
This document discusses the antimicrobial therapy of neonates. It begins by defining antibiotics and classifying them based on their mode of action, spectrum of activity, and mechanism of action. Common bacterial diseases of neonates include neonatal diarrhea, joint ill, and pneumonia. For neonatal diarrhea, enrofloxacin is the drug of choice. For coccidiosis, sulfonamides are used. Metronidazole treats giardiasis. Penicillin and streptomycin are effective against joint ill. Macrolides like erythromycin and tylosin are useful to treat pneumonia. The document provides market drugs available in Pakistan for the different conditions.
Anti-infective agents are drugs designed to selectively target and kill invading microorganisms without harming the host's cells. Paul Ehrlich was the first scientist to develop a synthetic chemical with this property in the 1920s. Anti-infectives work by interfering with microbial cell walls, protein synthesis, DNA synthesis, or cell membranes. Their goal is to reduce microbial populations to levels the immune system can handle. Microbes can develop resistance by modifying drug targets or transport mechanisms. Careful dosing and limiting inappropriate use can help prevent resistance.
This document discusses antibiotics, including their definition, history, classification, mechanisms of action, uses, and complications. Antibiotics are medications that kill or inhibit the growth of bacteria and were first discovered by Alexander Fleming in 1928. They are classified based on their mechanism of action (inhibiting cell wall, protein, or nucleic acid synthesis), spectrum of activity (narrow or broad), and mode of action (bacteriostatic or bactericidal). While antibiotics have reduced mortality from bacterial infections, their overuse and misuse has led to increased antibiotic resistance in bacteria.
This document summarizes the salient features of β-lactam antibiotics and their mode of action, classification, spectrum of activity, and common adverse effects. It discusses penicillins, cephalosporins, and their subclasses. Penicillins inhibit bacterial cell wall synthesis by binding to penicillin binding proteins. They are more active against gram-positive bacteria. Cephalosporins have a similar mode of action but their activity spectrum varies between generations from gram-positive to broad-spectrum. Common adverse effects for both classes include hypersensitivity reactions and dysbiosis.
Antibiotics lecture- 13- medical rev.pptAhmedKasem39
This document provides an overview of antibiotics and antimicrobial agents presented by Prof Hanan Habib and Dr. Ali Somily. The objectives are to define key antibiotic concepts, recognize antibiotic classes and their mechanisms of action, spectrum of activity, and side effects. It discusses various classes of antibiotics that inhibit cell wall synthesis, alter cell membranes, inhibit protein synthesis, or act on nucleic acids. Ideal antibiotic criteria and principles of antimicrobial therapy are also reviewed. Mechanisms of antibiotic resistance and criteria for an ideal antimicrobial are presented. References for further information include the textbook Sherries Medical Microbiology.
The document provides information on antibiotics used in pediatric dentistry. It discusses the classification of bacteria and antibiotics, the mechanisms of action of antibiotics including inhibition of cell wall synthesis, cell membrane function, protein synthesis and nucleic acid synthesis. It also covers principles for choosing the appropriate antibiotic, maximum dosage, and commonly used antibiotics like penicillin, erythromycin, clindamycin, amoxicillin, cephalosporins, tetracyclines and metronidazole. Calculations for pediatric antibiotic dosages and classifications of various antibiotics are also summarized.
The document discusses antimicrobial drugs and antibiotics. It begins by noting that the modern era of antibiotics started with Fleming. It then defines antimicrobial drugs as chemicals that interfere with microbial growth within a host, including antibacterial, antiviral, antiparasitic and antifungal drugs. Antibiotics are natural products produced by bacteria and fungi that kill or inhibit other microorganisms. Antimicrobial drugs are further classified based on their spectrum of action, source, chemical nature and mode of action. The document also discusses mechanisms of action, resistance, and ideal properties of antimicrobial drugs.
Lecture 6 protein synthesis inhibiting antibioticsana munir
This document discusses several classes of antibiotics that inhibit protein synthesis in bacteria. It focuses on chloramphenicol, aminoglycosides, and tetracyclines. Chloramphenicol inhibits peptide bond formation on bacterial ribosomes. Aminoglycosides interfere with protein initiation by causing incorrect mRNA reading. Tetracyclines prevent amino acid attachment to bacterial ribosomes. All three classes bind to different sites on the bacterial ribosome to inhibit protein synthesis and treat various bacterial infections, but have potential toxic side effects when used.
The document discusses the history and development of antibiotics and antimicrobial chemotherapy. It begins with the discovery of sulphonamides in 1935 and penicillin in 1928. It describes the types of antibiotics including bactericidal drugs that kill pathogens and bacteriostatic drugs that inhibit growth. The document also covers the mechanisms of action, targets, and development of resistance to antibiotics.
This document discusses various classes of antimicrobial agents used to treat bacterial, viral, and fungal infections. It describes the mechanisms of action and examples of drugs that inhibit cell wall synthesis, cell membrane function, protein synthesis, nucleic acid synthesis, and other metabolic processes in bacteria. It also discusses mechanisms of drug resistance in bacteria and summarizes treatment approaches for herpes virus infections and HIV/AIDS.
Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
DECLARATION OF HELSINKI - History and principlesanaghabharat01
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In some case, your chronic prostatitis may be related to over-masturbation. Generally, natural medicine Diuretic and Anti-inflammatory Pill can help mee get a cure.
The skin is the largest organ and its health plays a vital role among the other sense organs. The skin concerns like acne breakout, psoriasis, or anything similar along the lines, finding a qualified and experienced dermatologist becomes paramount.
share - Lions, tigers, AI and health misinformation, oh my!.pptxTina Purnat
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Travel vaccination in Manchester offers comprehensive immunization services for individuals planning international trips. Expert healthcare providers administer vaccines tailored to your destination, ensuring you stay protected against various diseases. Conveniently located clinics and flexible appointment options make it easy to get the necessary shots before your journey. Stay healthy and travel with confidence by getting vaccinated in Manchester. Visit us: www.nxhealthcare.co.uk
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2. WHAT IS AN
ANTIBIOTIC?
Antibiotics a chemical substance produced by
a microorganism that inhibits the growth of or
kills other microorganisms.
Antimicrobial agents a chemical substance
derived from a biological source or produced
by chemical synthesis that kills or inhibits the
growth of microorganisms.
4. SOURCE OF
ANTIBACTERIAL AGENTS
Organisms develop resistance faster to the natural antimicrobials
Natural antibiotics are often more toxic than synthetic antibiotics
Benzylpenicillin and Gentamicin are natural antibiotics
Ampicillin and Amikacin are semi-synthetic antibiotics
Moxifloxacin and Norfloxacin are synthetic antibiotics
5. ROLE OF ANTIBIOTIC
To inhibit multiplication
Antibiotics have a bacteriostatic effect.
At which drug concentration is the bacterial
population inhibited?
Minimal Inhibitory Concentration = MIC
To destroy the bacterial population
Antibiotics have a bactericidal effect.
At which drug concentration is the bacterial
population killed?
Minimal Bactericidal Concentration = MBC
6.
7. CHOOSING THE RIGHT
ANTI-INFECTIVE
Is an antibiotic indicated?
Use empirical therapy routinely
Narrow spectrum
Avoid toxicity and side effects
Bactericidal vs bacteriostatic
Cost
Avoid allergies
8. MAIN DIFFERENCE
BETWEEN HUMAN CELL
AND MICROBIAL CELL
Human cellMicrobial cell
It is dependent on other cells .Cell is isolated and Independent.
The wall is absentThick protective cell wall is present .
Cytoplasmic bridges are present which
help in inter-cellular transport in
between neighboring cells.
Cell membrane : No cytoplasmic
bridges as there is only one cell.
Absent mostly. Except for ciliated cells
in respiratory tract & gut.
Flagella for movement, pili for sexual
reproduction.
Prominent nucleus with nuclear
membrane. So called as an eukaryote
type.
Nucleus is Absent. Instead nuclear
content like DNA are present in
cytoplasm. No distinct nucleus, so
called as prokaryote
80 s type with 60 s and 40 s sub units.RNA : 70 s type with 50s and 30s type
sub units.
9.
10. ODONTOGENIC
INFECTIONS
are caused by oral pathogens that
inhabit the surface of the teeth and
oral mucous membranes and are
also found in the gingival sulcus
and saliva
12% of antibiotics in the outpatient
setting are given for odontogenic
infections
12. WHAT PATHOGENS ARE WE
DEALING WITH?
Gram Positive?
Gram Negative?
Mixed Infection?
Aerobes?
Facultative?
Anaerobes?
13.
14. ODONTOGENIC
INFECTIONS
300-700 species of which more than 50%
cannot be cultured
Aerobic - anaerobic infections
Aerobes only (7%)
Mixed (60%)
Anaerobes only (33%)
Average isolates per specimen - 4
Gram + Aerobic & Facultative Streptococci
Common pathogen and most numerous
Produce hyaluronidase and streptokinase
15.
16.
17.
18. WHAT TYPE OF
ANTIBIOTIC SHOULD WE
USE?
Bacteriostatic?
Bactericidal ?
Narrow Spectrum?
Broad Spectrum?
19. BACTERIOSTATIC VS
BACTERICIDAL
Bactericidal action necessary in endocarditis,
meningitis, osteomyelitis,neutropenia
Disadvantage of bactericidal: rapid bacterial lysis in
meningitis with overwhelming inflammatory
response with increased mortality
Advantage of bacteriostatic: clindamycin in staph
TSS( toxic shock syndrome) effective in inhibiting
TSST-1( toxic shock syndrome toxin) production
without excessive inflammatory response
Cidal and static should not uses together
20. STRUCTURES OF
BACTERIAL CELL
MEMBRANE
Natural Resistance
Enterococcus- PBP’s are different from other Gram-positives (also higher
lipid content in cell wall), which causes a low level resistance to penicillins
and resistance to C1G.
21.
22. STRUCTURES OF BACTERIAL
CELL MEMBRANE
Natural Resistance- Many Gram-negative organisms are naturally
resistant to penicillin G and oxacillin because the drug is
prevented from entering the cell by the LPS which blocks the
porins.
Gram-negatives are naturally resistant to vancomycin.
23.
24.
25. WHAT TYPE OF
ANTIBIOTIC SHOULD WE
USE?
Bactericidal ?
Bacteriostatic?
Narrow Spectrum?
Broad Spectrum?
29. BETA-LACTAMS
There are about 50 different Beta (ß)-lactams.
They are all bactericidal.
They are non-toxic.
They are relatively inexpensive.
organic acids and most are soluble in water.
inactivation by beta-lactamases
• Some more common Beta-lactamase enzymes include:
• Penicillinases
• Cephalosporinases
• ESBL’s
• Cephamycinases
• Carbapenemases
30. BETA-LACTAMASE
INHIBITORS(BLI)
have a beta(ß)-lactam ring, but have weak or poor
antibacterial activity.
They have a very high affinity for ß-lactamases
They act as a trap, and are hydrolyzed in preference
to the ß-lactam drug.
The drug is left intact to act on the bacteria (cell
wall)
Should be called penicillinase inhibitors, because
they are active against: ƒStaph penicillinase,
Penicillinase of K. pneumoniae
31. BETA-LACTAMASE
INHIBITORS(BLI)
ESBL (to a greater or lesser degree)- if the
penicillinase is being overproduced, the
inhibitor effect may be diluted (Inoculum
Effect)
Inhibitors are active against all penicillinase
but never on cephalosporinase
NEW ISSUE- BLI can act as inducers and actually
stimulate enzyme (betalactamase) production. It
ispossible to see the following:
Pseudo monas Ticarcillin = S Ticarcillin/Clavulanic = R
Enterobacteriaceae Piperacillin = S Piperacillin/Tazobactam =
R
40. aztreonam differs from those of other β-lactam
antibiotics and more closely resembles that of an
aminoglycoside.
Aztreonam has activity only against gram-negative
bacteria
42. Aminoglycosides:
Spectrum of Action
Rapid bactericidal effect
Broad spectrum of action
Gram-negative infections
Gram-positives, except Streptococus and
Enterococcus. Must combine an aminoglycoside
(Gentamicin or Streptomycin) with a penicillin,
ampicillin or vancomycin for severe enterococcal
infections (Synergy Testing).
In serious infection, used in association with beta-
lactams or fluoroquinolone
Nephrotoxic and toxic for ears
43. AMINOGLYCOSIDE
Mode of action:
• Target = Ribosome in cytoplasm
• Aminoglycosides are positively charged molecules
• The negative charge of bacteria is due to LPS in
the outer membrane and the peptidoglycan
(notably the teichoic acid).
• The drugs cross the cytoplasmic membrane via
respiratory enzymes(involved in aerobic
respiration).
44. AMINOGLYCOSIDE
Aminoglycosides bind to the RNA of the
30S ribosomal sub-unit.
Release of incomplete, toxic proteins
The bactericidal activity of aminoglycosides
ultimately stops protein synthesis and
dramatically damages the cytoplasmic
membrane.
45.
46.
47. Bacteriostatic
Their spectrum of activity is limited to Gram-positive
cocci such as Streptococci and Staphylococci. These
antibiotics are also active against anaerobes.
Clindamycin used in osteomyelitis of the jaws.
Clindamycin dose not in routine of odontogenic infection
48. The drugs enter a Gram-positive cell without any problem.
In Gram-negative bacteria there is no entry because MLSK are lipophilic
molecules.
They cannot cross the outer membrane which is hydrophilic. “Oil and
water don’t mix”.
MLSK are also large molecules that cannot pass through the porins (which
are also aqueous channels) – impermeability.
Most Gram-negatives are naturally resistant to MLSK Antibiotics
MLSK group are structurally distinct but have a similar mode of action by
binding the 50S ribosomal subunit
52. Tetracyclines:
Spectrum of Action: Broad spectrum,
resistance is common
Primarily for treatment of genital infections (chlamydiae) and atypicals
(Rickettsiae, Mycoplasma).Growth promotor in animal husbandry.
Toxicity:
Diffuse well in cells and bones.
Not recommended for pregnant women and children (less than 2 years old)
because of the toxicity on bones and teeth of the fetus.
53. TETRACYCLIN
Tetracycline = Short acting
Minocycline and Doxycycline = Long acting
Minocycline and Doxycycline are more
active than Tetracycline.
Used extensivly in periodontitis and
periodontal disease
tetracycline exists as a mixture of two forms
- lipophillic and hydrophillic, Helps the
antibiotic gain entry in to the Gram-pos and
neg cel
54. TETRACYCLIN
it’s target - the 30s ribosome
Gram-positives have no natural resistance to the
tetracyclines.
Of the Gram-negative organisms only Proteus mirabilis is
naturally resistant
55. 1st Generation Quinolones: Only for Gram-negatives,
used to treat urinary tract infections
Fluoroquinolones: Ciprofloxacin,Levofloxacin, Norfloxacin,
Ofloxacin)More effective (lower MIC values).
Spectrum extended to cover Staphylococci, Streptococci and
Pneumococci(sparfloxacin).
62. IMPORTANT
NOTES
• In culture and sensitivity testing on 94 patients with odontogenic
abscesses, penicillin V was the least effective antibiotic for
eradicating bacterial isolates. Despite this, more than 95% of
patients treated with surgical incision and drainage in conjunction
with penicillin V recovered satisfactorily.
• Amoxicillin has a broader spectrum of activity than penicillin V, but
does not provide any better coverage in treating odontogenic
infections. Its dosing schedule and ability to be taken with food may
make it more acceptable for patients, resulting in better compliance.
• Cephalosporins are not a first-line treatment in the management
of odontogenic infections.
63. IMPORTANT
NOTES
• Clindamycin: Clindamycin inhibits bacterial protein synthesis and
is bactericidal at high dosages. Its use has increased in recent
years due to increasing concern over penicillin resistance. For
example, it has replaced penicillin as the recommended
antibiotic for the management of odontogenic infections
• Clindamycin has excellent coverage of gram positive cocci and
anaerobic bacteria. Eikenellais inherently resistant to clindamycin
and alternative antibiotics should be considered if this species is
found to be the causative organism.
64. IMPORTANT
NOTES
Fluoroquinolones: The broad-spectrum antibiotic has excellent
bacterial coverage in the setting of an odontogenic infection. It is
effective against Eikenella and most strains of bacteria that produce
beta lactamase.
It has the highest rate of bacterial susceptibility among all antibiotics
including penicillin and clindamycin for odontogenic infections.
However, given its broad spectrum and high cost, it should be
considered as a secondl ine therapy to penicillin V, metronidazole
and clindamycin.
Penicillin in conjunction with metronidazole provides excellent
bacterial coverage for most odontogenic infections and should be
considered the antibiotic of choice.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76. DO IT , OVERCOME
THE PROBLEM
Bacteria never die
Be happy