Does probenecid affect tigecycline dosing?
No, tigecycline's dosage does not need alteration when used with probenecid. Tigecycline, a glycylcycline antibiotic, is primarily eliminated via biliary/fecal excretion (about 59% unchanged), with minimal renal clearance (about 33% total, <15% unchanged).[1][2] Probenecid inhibits renal tubular secretion of drugs like penicillins and cephalosporins but has no clinically significant interaction with tigecycline due to its low dependence on active renal secretion.[1]
How tigecycline pharmacokinetics work
Tigecycline achieves high tissue penetration with a large volume of distribution (7-10 L/kg). Its half-life is 42 hours, supporting once- or twice-daily dosing without accumulation in hepatic impairment. Renal impairment studies show no dose adjustment needed for creatinine clearance above 10 mL/min, as clearance changes are minor (20-30% decrease in severe cases).[1][3]
Evidence from drug interaction data
Tigecycline's prescribing information lists no probenecid interaction among 15+ studied combinations (e.g., warfarin, digoxin, CYP3A4 drugs). In vitro and clinical data confirm probenecid does not alter tigecycline's AUC or Cmax.[1] No case reports or post-marketing data indicate issues.
When tigecycline dose adjustments are required
Adjust for hepatic impairment only:
- Child-Pugh B/C: 50 mg once daily after 100 mg load.
No changes for renal impairment, dialysis, or obesity.[1]
| Condition | Dose Adjustment |
|-----------|-----------------|
| Mild-moderate hepatic (Child-Pugh A/B) | None |
| Severe hepatic (Child-Pugh C) | 50 mg q24h after load |
| Any renal impairment | None |
| Probenecid co-use | None |
Alternatives if renal interactions matter
For infections where probenecid boosts beta-lactam levels (e.g., high-dose penicillin), tigecycline remains unaffected. Consider eravacycline (similar glycylcycline, biliary elimination) or standard tetracyclines if tigecycline unavailable.[4]
[1]: Tygacil (tigecycline) Prescribing Information
[2]: Tigecycline Pharmacokinetics Review
[3]: FDA Label Section 8.6 Renal Impairment
[4]: Eravacycline vs Tigecycline Comparison