Clindamycin (Cleocin)

Surgical antibiotic prophylaxis - 900 mg IV over 30 min before incision in beta-lactam-allergic patients; redose every 6 hr or after blood loss greater than 1.5 L. Pediatric prophylaxis 10 mg/kg IV (max 900 mg).

Neuromuscular blockade potentiation - Clinically significant prolongation of vecuronium, rocuronium, and other non-depolarizing NMBs; use train-of-four (TOF) monitoring and have neostigmine or sugammadex ready.

Always infuse over 30–60 min - Rapid bolus has caused hypotension and cardiac arrest; do not push.

C. difficile risk - Highest among common surgical antibiotics; reserve for true beta-lactam allergy or specific anti-toxin indications.

Toxic shock and necrotizing soft tissue infection - Add to a beta-lactam in streptococcal or staphylococcal toxic shock syndrome and in necrotizing fasciitis for anti-toxin (anti-exotoxin) effect.

Endocarditis prophylaxis - Per the 2021 American Heart Association update, 600 mg IV or PO is no longer first-line because of resistance and adverse-event concerns; cefazolin or azithromycin preferred where appropriate.

Group B Streptococcus prophylaxis in obstetrics - Use only with documented clindamycin susceptibility because resistance now exceeds 20–40% in many regions; cefazolin is preferred in non-anaphylactic penicillin allergy.

Management of excessive effect - Stop the drug and treat C. difficile per Infectious Diseases Society of America (IDSA) guideline (oral fidaxomicin or vancomycin); residual NMB is reversed with sugammadex or neostigmine guided by TOF.

Drug Interactions - Potentiates non-depolarizing NMB; antagonistic with macrolides (do not co-administer); minor effect on warfarin.

Pediatric Implications - 10–13 mg/kg IV every 6–8 hr (max 40 mg/kg/day for IV). Avoid rapid bolus; surgical prophylaxis dose 10 mg/kg.

Obstetric Implications - Pregnancy category B; safe in pregnancy and lactation. Used for GBS prophylaxis only with proven susceptibility, otherwise cefazolin is preferred.

Absolute: history of pseudomembranous colitis or prior C. difficile infection.

Relative: severe hepatic impairment, history of inflammatory bowel disease, concurrent macrolide therapy.

Caution: critically ill patients receiving non-depolarizing neuromuscular blockers, elderly (higher C. difficile risk), Group B Streptococcus prophylaxis without documented susceptibility.

Surgical prophylaxis: 900 mg IV over 30 min before incision; redose every 6 hr or after greater than 1.5 L blood loss.

Treatment of serious infection: 600–900 mg IV every 8 hr (max 4.8 g/day).

Pediatric prophylaxis: 10 mg/kg IV (max 900 mg).

Pediatric treatment: 10–13 mg/kg IV every 6–8 hr.

600 mg IM as a single dose; rarely used and painful.

Binds the 50S ribosomal subunit and inhibits bacterial peptidyl transferase activity; bacteriostatic at usual doses and bactericidal at high concentrations against susceptible organisms; suppresses bacterial exotoxin synthesis.

Hepatic (CYP3A4, CYP3A5).

Biliary and renal.

Always infuse IV in 50 mL or more of saline or D5W over 30–60 min; rapid bolus has caused cardiac arrest.

Highest C. difficile risk of common surgical antibiotics — use only when truly indicated.

Excellent bone, lung, and abscess penetration; useful adjunct in necrotizing soft tissue infection.

GBS resistance is rising — only use for GBS prophylaxis with documented clindamycin susceptibility.

Reconstitute IV in saline or D5W to a maximum of about 18 mg/mL; final infusion concentration 6–12 mg/mL.