Clindamycin Dosing for Bacterial Infections
For most serious bacterial infections requiring parenteral therapy in adults, clindamycin should be dosed at 600 mg IV every 8 hours, with escalation to 600-900 mg IV every 8 hours for severe infections including necrotizing fasciitis, intra-abdominal infections, and proven or suspected Bacteroides fragilis. 1, 2, 3
Adult Intravenous Dosing
Standard Serious Infections
- 600 mg IV every 8 hours is the recommended dose for:
Severe/Life-Threatening Infections
- 600-900 mg IV every 8 hours for:
Pelvic Inflammatory Disease
- 900 mg IV every 8 hours in combination with gentamicin (loading dose 2 mg/kg, then 1.5 mg/kg every 8 hours) 4, 5
- Continue IV therapy for at least 48 hours after clinical improvement, then transition to oral 4
Adult Oral Dosing
Moderate Infections
- 300-450 mg PO three to four times daily for:
Severe Infections (Oral Route)
- 300-450 mg PO every 6 hours (equivalent to four times daily) for more severe infections when oral route is appropriate 3, 6
Critical caveat: Single IM injections should not exceed 600 mg 3. IV infusion rates should not exceed 30 mg per minute, and concentrations should not exceed 18 mg/mL 3.
Pediatric Dosing
Intravenous Dosing (Children ≥1 month to 16 years)
- 25-40 mg/kg/day divided into 3-4 doses (or 10-13 mg/kg/dose every 6-8 hours, not exceeding 40 mg/kg/day total) 1, 4
- Higher end of dosing range (40 mg/kg/day) for:
Oral Dosing (Children able to swallow capsules)
- Serious infections: 8-16 mg/kg/day divided into 3-4 equal doses 6
- Severe infections: 16-20 mg/kg/day divided into 3-4 equal doses 6
- MRSA infections (susceptible strains): 30-40 mg/kg/day in 3-4 divided doses 4
Neonates (<1 month)
- 15-20 mg/kg/day in 3-4 equal doses 3
- For post-menstrual age (PMA) ≤32 weeks: 5 mg/kg every 8 hours 3
- For PMA >32 to ≤40 weeks: 7 mg/kg every 8 hours 3
Important pediatric consideration: Clindamycin should NOT be used if there is concern for infective endocarditis or endovascular source of infection, but may be considered in children whose bacteremia rapidly clears and is not related to an endovascular focus 1.
Duration of Therapy
Infection-Specific Durations
- Skin and soft tissue infections: 7 days for most cases, up to 14 days depending on clinical response 1, 4
- Pneumonia: 7-21 days depending on extent of infection 1, 4
- Osteomyelitis: Minimum 8 weeks, with possible additional 1-3 months of oral rifampin-based combination therapy 1, 4
- Septic arthritis: 3-4 weeks 1
- Bacteremia/endocarditis: 2-6 weeks depending on source and metastatic foci 1, 4
- β-hemolytic streptococcal infections: At least 10 days 3, 6
Combination Therapy Considerations
When to Add Gram-Negative Coverage
- Clindamycin lacks activity against aerobic gram-negative rods (E. coli, Pseudomonas) 5, 7
- For mixed infections or intra-abdominal infections, combine with:
Rifampin Addition for Bone Infections
- Consider adding rifampin 600 mg daily or 300-450 mg PO twice daily for osteomyelitis after clearance of bacteremia 1, 4
Critical Resistance and Susceptibility Issues
Clindamycin should only be used for MRSA infections if local clindamycin resistance rates are <10% 4. There is potential for cross-resistance and emergence of resistance in erythromycin-resistant strains, with inducible resistance possible in MRSA 1.
Monitoring and Clinical Response
- Assess clinical response within 48-72 hours of initiating therapy 2, 4
- If no improvement occurs, consider inadequate source control (drainage) or deeper infection requiring imaging 4
- For abscess-associated cellulitis, incision and drainage is the cornerstone of treatment and may be sufficient alone for simple abscesses 4
Major Adverse Effect Warning
If significant diarrhea occurs during therapy, clindamycin must be discontinued immediately due to risk of Clostridioides difficile-associated diarrhea and pseudomembranous colitis 3, 6. This is an uncommon but serious complication that responds to discontinuation and treatment with vancomycin or metronidazole 5.