Clindamycin
Cleocin
Lincosamide protein-synthesis inhibitor
Binds 50S ribosomal subunit, blocks peptide-bond formation. Bacteriostatic against most organisms; bactericidal against susceptible streptococci. Excellent activity against anaerobes and gram-positive cocci including community-acquired MRSA.
Indications
- •Surgical prophylaxis in patients with severe penicillin/cephalosporin allergy (alternative to cefazolin)
- •Anaerobic infections (abscess, aspiration pneumonia, clostridial myonecrosis)
- •Toxin-suppression in necrotizing fasciitis or toxic shock syndrome
- •Endocarditis prophylaxis in PCN-allergic patients (when indicated)
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Surgical prophylaxis | 900 mg IV within 60 min before incision; redose at 6 h or after >1500 mL blood loss | 10 mg/kg IV (max 900 mg) |
| Severe infection | 600–900 mg IV q8 h | — |
Pharmacokinetics
Onset minutes IV. Peak 45 min. Half-life 2–3 h. Hepatic metabolism + biliary excretion. Penetrates bone, abscess, lung, soft tissue well; poor CSF penetration.
Hemodynamic effects
Minimal at standard dose. Rapid IV bolus can cause hypotension and cardiopulmonary arrest — infuse over 30 min minimum.
Respiratory effects
Minimal direct effect.
Side effects
- !C. difficile colitis — historically the highest-risk antibiotic for CDI (10× baseline)
- !Diarrhea (15–20%)
- !Allergic reactions / rash
- !Hepatotoxicity (rare)
Contraindications
- ×Hypersensitivity to clindamycin or lincomycin
Clinical pearls
- ★PROPHYLAXIS NICHE: when patient has SEVERE beta-lactam allergy (anaphylaxis, SJS), clindamycin is the cefazolin alternative. For most 'PCN-allergic' patients, a cephalosporin is still safe (cross-reactivity 1–2%).
- ★SLOW INFUSION: 900 mg over 30 min minimum. Rapid IV push has caused cardiac arrest; never push as a bolus.
- ★TIME WINDOW: give within 60 min of incision (120 min for vancomycin and fluoroquinolones). Joint Commission core measure.
- ★C. DIFF RISK: highest of any prophylactic antibiotic. Single-dose prophylaxis carries less risk than chronic dosing — but not a routine choice when cefazolin is an option.
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Other drugs in Antibiotics
- Cefazolin
β-lactam — inhibits bacterial cell wall PBPs.
- Vancomycin
Inhibits cell wall synthesis (binds D-Ala-D-Ala). Active against MRSA + gram-positives.
- Gentamicin
Binds 30S ribosomal subunit, causes misreading of mRNA → defective bacterial protein synthesis. Bactericidal, concentration-dependent killing. Synergy with cell-wall agents (β-lactams, vancomycin) for gram-positive endocarditis.
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