Tigecycline for MRSA Infections
Tigecycline is FDA-approved for complicated skin and soft tissue infections (cSSTI) caused by MRSA, but it should NOT be used as first-line therapy and is specifically NOT recommended for bloodstream infections or pneumonia. 1
Critical FDA Black Box Warning
- Tigecycline carries an increased all-cause mortality risk (0.6% absolute increase, 95% CI 0.1-1.2%) compared to other antibiotics and should be reserved only for situations when alternative treatments are not suitable 1
- The drug is specifically contraindicated for hospital-acquired or ventilator-associated pneumonia due to greater mortality and decreased efficacy in clinical trials 1
When Tigecycline May Be Considered for MRSA
FDA-Approved Indication
- Tigecycline is approved for complicated skin and skin structure infections caused by MRSA (both methicillin-susceptible and -resistant S. aureus) in patients ≥18 years old 1
- Dosing: 100 mg IV initial dose, followed by 50 mg IV every 12 hours for 5-14 days 1
Specific Restrictions and Contraindications
- Do NOT use tigecycline for MRSA bloodstream infections (bacteremia) - no evidence supports this indication 2
- Do NOT use tigecycline for MRSA pneumonia (HAP/VAP) - associated with increased mortality 2, 1
- Avoid tigecycline for diabetic foot infections - clinical trial failed to demonstrate non-inferiority 1
- For complicated intra-abdominal infections, tigecycline showed inferior clinical cure rates and higher mortality (OR 1.33,95% CI 1.03-1.72) compared to other antibiotics 2
Preferred First-Line Alternatives for MRSA
For Skin and Soft Tissue Infections
- Vancomycin or linezolid are recommended as first-line IV options for MRSA cSSTI, with daptomycin, ceftaroline, dalbavancin, and tedizolid as additional alternatives 2, 3
- For oral therapy: trimethoprim-sulfamethoxazole (1-2 double-strength tablets twice daily), doxycycline (100 mg twice daily), clindamycin (300-450 mg three times daily), or linezolid (600 mg twice daily) 2, 4, 5
For Pneumonia
- Vancomycin or linezolid are the recommended options for suspected or confirmed MRSA pneumonia 2
- Linezolid may have advantages in hospital-acquired MRSA pneumonia 6
Clinical Evidence for Tigecycline in MRSA
- In a Phase 3 trial comparing tigecycline to vancomycin for MRSA infections, clinical cure rates were similar: 81.4% vs 83.9% in microbiologically evaluable patients, and 75.0% vs 81.8% in modified intent-to-treat populations 7
- Tigecycline caused significantly more nausea/vomiting (41.0%) compared to vancomycin (17.9%), though most cases were mild 7
- A German observational study showed 94% clinical success with tigecycline monotherapy for documented MRSA infections, but this was in a non-comparative setting 8
Key Clinical Pitfalls
- Never use tigecycline as empiric first-line therapy for severe MRSA infections - reserve for situations where all other options have failed or are contraindicated 1
- Tigecycline is bacteriostatic against most organisms (though bactericidal against S. pneumoniae), making it less ideal for severe infections requiring rapid bacterial killing 1
- Monitor closely for treatment failure, especially in Acinetobacter infections where resistance can develop during therapy via MDR efflux pumps 1
- The drug should only be used when culture and susceptibility data confirm MRSA and document tigecycline susceptibility 1