ANTIMICROBIALS AND ANTI-INFECTIVE PHARMACOTHERAPY
Classification and Actions of Anti-Infective Drugs
Mechanisms of Anti-Infective Drugs
Anti-infective drugs affect the target organism's structure, metabolism, or life cycle.
Antibiotics are natural substances produced by bacteria to kill other bacteria.
Bactericidal agents kill bacteria, while bacteriostatic agents slow their growth.
Selection of Effective Antibiotics
Culture and Sensitivity (C & S) Testing involves examining specimens for
microorganisms, identifying them, and testing their sensitivity to different antibiotics.
Broad-spectrum antibiotics may be initiated before lab culture completion.
Superinfections are secondary infections that occur when host flora are excessively killed
by antibiotics.
Antibacterial Drugs
Classes of antibiotics include Penicillin, Cephalosporins, Tetracyclines, Macrolides,
Aminoglycosides, Fluoroquinolones, and Sulfonamides.
Penicillins work by disrupting bacterial cell walls, most effective against gram-positive
bacteria.
Examples of penicillins include Penicillin G, which is administered intravenously or
intramuscularly.
Pharmacotherapy with Penicillins
Mechanism of Action
Penicillins kill bacteria by disrupting their cell walls, allowing water to enter.
They are most effective against gram-positive bacteria.
, Prototype Drug: Penicillin G
Therapeutic Class: Antibacterial
Pharmacologic Class: Cell wall inhibitor; natural penicillin
Uses: Effective against Streptococci, Pneumococci, and Staphylococci.
Administration and Adverse Effects
Only 15–30% of an oral dose of Penicillin G is absorbed.
Adverse effects include anaphylaxis, diarrhea, nausea, and vomiting.
Pharmacotherapy with Cephalosporins
Mechanism of Action
Cephalosporins bind to bacterial cell walls, inhibiting cell-wall synthesis.
They have broad-spectrum activity against gram-negative organisms.
Prototype Drug: Cefazolin (Ancef, Kefzol)
Therapeutic Class: Antibacterial
Pharmacologic Class: First-generation cephalosporin
Actions and Uses: Commonly used for respiratory, urinary, bone, and joint infections.
Administration and Adverse Effects
Administer IM injections deep into a large muscle mass to prevent tissue injury.
Adverse effects may include rash and diarrhea, with a lower likelihood of allergic
reactions.
Pharmacotherapy with Tetracyclines
Actions and Uses
Tetracyclines inhibit protein synthesis and are effective against a broad spectrum of
bacteria.
Classification and Actions of Anti-Infective Drugs
Mechanisms of Anti-Infective Drugs
Anti-infective drugs affect the target organism's structure, metabolism, or life cycle.
Antibiotics are natural substances produced by bacteria to kill other bacteria.
Bactericidal agents kill bacteria, while bacteriostatic agents slow their growth.
Selection of Effective Antibiotics
Culture and Sensitivity (C & S) Testing involves examining specimens for
microorganisms, identifying them, and testing their sensitivity to different antibiotics.
Broad-spectrum antibiotics may be initiated before lab culture completion.
Superinfections are secondary infections that occur when host flora are excessively killed
by antibiotics.
Antibacterial Drugs
Classes of antibiotics include Penicillin, Cephalosporins, Tetracyclines, Macrolides,
Aminoglycosides, Fluoroquinolones, and Sulfonamides.
Penicillins work by disrupting bacterial cell walls, most effective against gram-positive
bacteria.
Examples of penicillins include Penicillin G, which is administered intravenously or
intramuscularly.
Pharmacotherapy with Penicillins
Mechanism of Action
Penicillins kill bacteria by disrupting their cell walls, allowing water to enter.
They are most effective against gram-positive bacteria.
, Prototype Drug: Penicillin G
Therapeutic Class: Antibacterial
Pharmacologic Class: Cell wall inhibitor; natural penicillin
Uses: Effective against Streptococci, Pneumococci, and Staphylococci.
Administration and Adverse Effects
Only 15–30% of an oral dose of Penicillin G is absorbed.
Adverse effects include anaphylaxis, diarrhea, nausea, and vomiting.
Pharmacotherapy with Cephalosporins
Mechanism of Action
Cephalosporins bind to bacterial cell walls, inhibiting cell-wall synthesis.
They have broad-spectrum activity against gram-negative organisms.
Prototype Drug: Cefazolin (Ancef, Kefzol)
Therapeutic Class: Antibacterial
Pharmacologic Class: First-generation cephalosporin
Actions and Uses: Commonly used for respiratory, urinary, bone, and joint infections.
Administration and Adverse Effects
Administer IM injections deep into a large muscle mass to prevent tissue injury.
Adverse effects may include rash and diarrhea, with a lower likelihood of allergic
reactions.
Pharmacotherapy with Tetracyclines
Actions and Uses
Tetracyclines inhibit protein synthesis and are effective against a broad spectrum of
bacteria.
