Protein synthesis Inhibitors: 3

Broad-spectrum antibiotics – Tetracyclines

MOA: Tetracyclines binds to the 30S subunit and prevent attachment of aminoacyl tRNA to the A site. They also inhibit the attachment of N-formyl methionine tRNA to the 30S subunit. Bacteriostatic.

Spectrum: First-line treatment of infection from Brucellae, Mima, and Bacteroides. G(+,-) coverage.

Resistance: Develops gradually. Mediated by R factor in G(-) bacteria.

Pharmacokinetics: Tetracyclines chelate calcium, magnesium, and aluminum. The various tetracyclines are cleared by glomerular filtration (except doxycycline).

Toxicity: Hypersensitivity; irritation of GI tract; superinfection; photosensitivity; liver damage; renal damage (due to outdated tetracyclinesFanconi syndrome); vestibular reactions; damage to teeth, bones, and nails (don’t give to pregnant women or small children).

Therapeutic place: Broad spectrum, oddball-organisms.

Tetracycline – UTIs.

Minocycline – Lower renal clearance.

Category: Pharmacology Notes