Antibiotic Mechanisms and Uses

These flashcards cover the mechanisms of action, examples, uses, and key nursing considerations for various classes of antibiotics.

Aminoglycosides

A class of antibiotics that inhibit bacterial protein synthesis by binding to the 30S ribosomal subunit.

Example Drugs (Aminoglycosides)

Gentamicin and Neomycin

pharmacokinetics (aminoglycosides)

Why did they distributed throughout the body, crossing the placenta and entering breastmilk

Common Uses (Aminoglycosides)

Severe gram-negative infections (e.g., sepsis, peritonitis).

Key Adverse Effects (Aminoglycosides)

Ototoxicity, nephrotoxicity; monitor BUN/Cr and hearing; peak/trough levels required.

Cephalosporins

A class of antibiotics that inhibit bacterial cell wall synthesis (β-lactam).

Example Drug (Cephalosporins)

Ceftriaxone.

Common Uses (Cephalosporins)

Respiratory, skin, urinary infections.

Key Adverse Effects (Cephalosporins)

Cross-sensitivity with penicillin; avoid alcohol (disulfiram reaction).

pharmacokinetics (cephalosporins)

cross the placenta and enter breastmilk

contraindications (cephalosporins)

allergies to cephalosporins or penicillin, hepatic or renal impairment

Fluoroquinolones

A class of antibiotics that inhibit DNA gyrase and topoisomerase IV.

Example Drugs (Fluoroquinolones)

Ciprofloxacin & Levofloxacin

Common Uses (Fluoroquinolones)

treating infections caused by susceptible strains of gram-negative, bacteria. (UTIs, respiratory, and skin infections)

Key Adverse Effects (Fluoroquinolones)

depression

pharmacokinetics (fluroquinolones)

absorbed in G.I. tract, metabolized in the liver, excreted in urine and feces and cross the placenta and enter breastmilk

contraindications (fluroquinolones)

known allergy, pregnancy, or lactating women and renal dysfunction

Penicillins

first anabiotic introduced for clinical use. Penicillin is only effective against gram-positive bacteria.

Example Drug (Penicillins)

Amoxicillin.

Common Uses (Penicillins)

Gram-positive infections, strep throat, ear infections.

pharmacokinetics (penicillins)

rapidly absorbed from the G.I. tract, reaching peak levels in 1 hour. Excreted unchanged in the urine and enter breastmilk.

contraindications (penicillins)

allergies to penicillin or cephalosporins, renal disease, use cautiously with patients who are pregnant or lactating

Sulfonamides

A class of antibiotics that inhibit folic acid synthesis (bacteriostatic).

• well absorbed from GI tract

• metabolized and liver, excreted in urine and our teratogenic

Example Drug (Sulfonamides)

cortimoxazole (Septra, Bactrim)

Common Uses (Sulfonamides)

UTIs, bronchitis, otitis media.

Tetracyclines

A class of antibiotics that bind to the 30S ribosome, blocking tRNA binding and protein synthesis.

Example Drug (Tetracyclines)

Doxycycline (Doryx, Acticlate)

Minocycline (Minocin)

Common Uses (Tetracyclines)

Acne, Lyme disease, respiratory infections.

Key Adverse Effects (Tetracyclines)

Tooth discoloration; photosensitivity; avoid dairy, antacids; not for pregnancy/children, take on empty stomach.

Macrolides

A class of antibiotics that inhibit protein synthesis by binding to the 50S ribosomal subunit.

Example Drug (Macrolides)

Azithromycin.

Antimycobacterials

A class of antibiotics that inhibit mycolic acid synthesis; affect RNA polymerase.

Example Drugs (Antimycobacterials)

Rifampin (Rifadin)

INH

Common Uses (Antimycobacterials)

Tuberculosis, leprosy.

Key Adverse Effects (Antimycobacterials)

Liver toxicity