Does Liver Function Affect Tigecycline Dosing?
Yes, tigecycline dosing requires adjustment in patients with moderate to severe hepatic impairment due to its primary metabolism and biliary excretion via the liver. No change is needed for mild impairment or normal function.[1]
Standard Dosing for Tigecycline
Tigecycline, an IV glycylcycline antibiotic, starts with a 100 mg loading dose, followed by 50 mg every 12 hours for approved infections like complicated skin/skin structure infections, intra-abdominal infections, and community-acquired pneumonia. Duration typically lasts 5-14 days.[1][2]
Adjustments for Hepatic Impairment
- Child-Pugh A (mild): No adjustment.
- Child-Pugh B (moderate): Loading dose 100 mg, then 25 mg every 12 hours.
- Child-Pugh C (severe): Loading dose 100 mg, then 25 mg every 12 hours (use with caution; limited data).
Monitor closely; tigecycline exposure increases 2- to 5-fold in moderate/severe cases, raising risks like nausea or elevated liver enzymes.[1][3]
Adjustments for Kidney Function
No renal dosing changes needed, even in end-stage disease or dialysis, as <20% is excreted renally.[1]
Why Liver Matters for Tigecycline
Tigecycline undergoes minimal hepatic metabolism but relies on bile for elimination. Hepatic impairment prolongs half-life from ~27 hours (normal) to ~50+ hours, necessitating lower maintenance doses to avoid accumulation.[2][3]
Monitoring and Risks in Liver Disease
Check baseline liver function tests. Common issues include elevated transaminases (up to 3x ULN), more frequent in hepatic impairment. Avoid in acute liver failure. Drug interactions (e.g., with warfarin) may compound risks.[1][2]
[1]: Tygacil (tigecycline) Prescribing Information, Pfizer
[2]: FDA Label for Tigecycline
[3]: Clinical Pharmacology Review, Tigecycline