Does Tigecycline Raise Transaminase Levels?
Yes, tigecycline, an intravenous glycylcycline antibiotic used for complicated skin infections and intra-abdominal infections, can elevate transaminase levels (ALT and AST). This is a recognized adverse effect in its prescribing information and clinical data.[1]
How Common Is This Side Effect?
Elevated liver enzymes occur in 1-10% of patients. In clinical trials, AST increases >2x upper limit of normal (ULN) affected up to 15% of tigecycline-treated patients, compared to 10% on comparators; ALT elevations >2x ULN reached 9-15%.[1][2] Most cases are mild and resolve after stopping treatment.
Why Does Tigecycline Affect the Liver?
Tigecycline inhibits bacterial protein synthesis but can cause direct hepatotoxicity, possibly via mitochondrial dysfunction or immune-mediated mechanisms. Risk rises with higher doses, prolonged use (>14 days), or underlying liver disease.[1][3]
Who Is at Higher Risk?
Patients with pre-existing liver impairment (Child-Pugh B/C), biliary obstruction, or concurrent hepatotoxic drugs face greater risk. Dosage adjustment is recommended for severe hepatic dysfunction: 100 mg loading dose, then 25 mg every 12 hours.[1]
What Do Doctors Monitor and Do?
Baseline and periodic liver function tests (LFTs) are standard. Discontinue if transaminases exceed 5-10x ULN or symptoms like jaundice appear. No specific antidote exists; supportive care resolves most cases.[1][2]
How Does It Compare to Other Antibiotics?
Tigecycline shows higher transaminase elevations than beta-lactams (e.g., piperacillin-tazobactam: <5%) but similar to some tetracyclines. Versus vancomycin, hepatic risk is comparable, though tigecycline has more GI side effects overall.[2][3]
[1]: Tygacil (tigecycline) Prescribing Information, Pfizer
[2]: ClinicalTrials.gov summaries for tigecycline trials (e.g., NCT00079599)
[3]: UpToDate: Tigecycline drug information