Antibiotics Pharmacology PDF

Pharmacology of Antibiotics Overview ANTIMICROBIAL drugs/agents Antimicrobial drugs/agents are drugs that are designed to act selectively on foreign organisms that have invaded and infected the body  ANTIMICROBIAL drugs AntiMICROBIAL drugs - range from Antibacterial...

Pharmacology of Antibiotics Overview ANTIMICROBIAL drugs/agents Antimicrobial drugs/agents are drugs that are designed to act selectively on foreign organisms that have invaded and infected the body  ANTIMICROBIAL drugs AntiMICROBIAL drugs - range from Antibacterials Antifungals Antivirals CLASSIFICATION OF ANTIBIOTICS  BASED ON : SPECTRUM OF ACTIVITY MODE OF ACTION  Spectrum of Activity : Narrow spectrum antibiotics Broad-spectrum antibiotics  NARROW SPECTRUM NARROW SPECTRUM Antibiotics affect only a few bacterial types Examples cloxacillin and rifampicin  BROAD-SPECTRUM Antibiotics affect many bacteria types. Meropenem (Meronem) is an example.  NOTE: Because Narrow spectrum antibiotics are selective, they are more active against single organisms than the broad spectrum antibiotics. Classification on Mode of Antibiotics action  2 Categories based on mode of action Bactericidal Bacteriostatic BACTERIOSTATIC antibiotics Antibiotics that interfere with the ability of the cell to reproduce/replicate without killing them are called BACTERIOSTATIC drugs.  BACTERICIDAL antibiotics Antibiotics that can aggressively cause bacterial death are called BACTERICIDAL.  BROAD VRS NARROW SPECTRUM Broad-spectrum antibiotics are versatile but can cause more damage to the body's normal flora, while narrow-spectrum antibiotics are more targeted but require precise identification of the infectious agent  HOW ANTIBIOTICS ARE INITIATED Empiric Antibiotic treatment Evidence based antibiotic treatment CULTURE AND SENSITIVITY Culture and sensitivity test  General Mechanisms of Action of Antibiotics agents: Inhibition the biosynthesis of bacterial cell WALL or destroy the cell wall Some destroy the cell membrane by changing its permeability Some inhibit DNA synthesis or replication Common Adverse Reactions to Antibiotics Therapy The most common adverse effects are due to the direct action of the drugs in the following organ system- Neuro, nephro and GI system Common Adverse Reactions to Antibiotics Therapy 1. Nephrotoxicity Antibiotics that are metabolized and excreted in the kidney most frequently cause kidney damage.. Common Adverse Reactions to Antibiotics Therapy 2. Gastro-intestinal toxicity Direct toxic effect to the cells of the GI tract can cause nausea, vomiting, stomach pain and diarrhea. Some drugs are toxic to liver cells and can cause hepatitis or liver failure. Common Adverse Reactions to Antibiotics Therapy 3. CNS toxicity When drugs can pass through the brain barrier and accumulate in the nervous tissues, they can interfere with neuronal function. Common Adverse Reactions to Antibiotics Therapy 4. Hypersensitivity Most protein antibiotics can induce the body’s immune system to produce allergic responses. Drugs are considered foreign substances and when taken by the individual, it encounters the body’s immune cells. Common Adverse Reactions to Antibiotics Therapy 5. Super-infections Opportunistic infections that develop during the course of antibiotic therapy are called SUPERINFECTIONS. As occurs in C. diff (Clostridium difficile) ANTIMICROBIAL RESISTANCE MECHANISM OF ANTIBIOTIC RESISTANCE Efflux pump Enzyme production by bacteria to destroy drug Thickening of cell wall  Factors that lead to antibiotic resistance Prescription of antibiotics when not needed Non compliance to antibiotics regimen ANTIMICROBIAL STEWARDSHIP  ANTIMICROBIAL STEWARDSHIP Antimicrobial stewardship is a coordinated effort aimed at improving and optimizing the use of antimicrobial medications, such as antibiotics, antifungals, and antivirals. The primary goals are to: Enhance Patient Outcomes**: Ensure that patients receive the most appropriate antimicrobial treatment, including the right drug, dose, and duration, which can improve treatment outcomes and reduce the risk of adverse effects. IMPORTANTLY TO USE ANTIBIOTICS ONLY WHEN NEEDED AND PRESCRIBED THANK YOU