Clindamycin
Clindamycin. Lincosamide antibiotic — binds 50S ribosomal subunit (overlapping macrolide site) blocking translocation. Anaerobic + gram-positive… Oral half-life 2.3 h.
Lincosamide antibiotic — binds 50S ribosomal subunit (overlapping macrolide site) blocking translocation. Anaerobic + gram-positive coverage. Highest C. difficile infection signal among antibiotics. CYP3A4 substrate.
PK: F 0.9 WAS A RELATIVE BIOAVAILABILITY READ AS AN ABSOLUTE ONE — "Mean relative bioavailability (point estimate) was 93% for AUC and 91% for Cmax", a comparison between two ORAL products. A new shape for the taxonomy. The only verified absolute figure in healthy humans is 0.53 (PMID:8517703), from the one study giving both an intravenous infusion and oral capsules in crossover; that paper also supplies a true steady-state volume of 0.79 L/kg. Its 0.75 belongs to the AIDS subgroup and is not stored. The intravenous row previously hung on a study with no intravenous arm at all. Half-life corrected 3 -> 2.3 h and shared across routes, which is legitimate here because absorption is not rate-limiting. PRODRUG CAVEAT: the intramuscular citation used clindamycin PHOSPHATE, an ester, so its absorption phase is hydrolysis-limited appearance of active drug rather than membrane transfer. The transdermal route is removed — it had no parameters and no citation, and the nearest published non-parenteral data are intravaginal at about 4% systemic.
Pharmacokinetics
- Oral — t½ 2.3 h · F 53% · Vd 55.3 L
- IV — t½ 2.3 h · F 100% · Vd 55.3 L
- Intramuscular — t½ 2.3 h · F 100% · Vd 55.3 L
Sources: PMID:10475141, PMID:8517703