Is a slight liver enzyme increase common with tigecycline?
Yes, slight increases in liver enzymes like ALT and AST occur in about 15-25% of patients on tigecycline, based on clinical trial data and post-marketing reports. These elevations are typically mild (1-3 times upper limit of normal), asymptomatic, and resolve after stopping the drug.[1][2]
What do clinical trials show for tigecycline liver effects?
In phase 3 trials for complicated skin/skin structure infections and intra-abdominal infections, elevated ALT happened in 19-26% of tigecycline patients versus 15-20% on comparators like vancomycin or imipenem. AST elevations were similar at 15-20% versus 10-15%. Serious hepatotoxicity was rare (<1%).[1][3]
How severe are these elevations usually?
Most cases stay grade 1-2 (mild to moderate) per NCI criteria. Grade 3-4 events (severe) occurred in <3% of tigecycline users, often with confounding factors like sepsis or other drugs. No tigecycline-specific liver failure signals emerged in large databases.[2][4]
Who is at higher risk for liver enzyme changes?
Patients with baseline liver issues, alcohol use, or concurrent hepatotoxins (e.g., acetaminophen) see higher rates. Obesity and longer tigecycline courses (>14 days) also correlate with elevations. Monitor closely in these groups.[2][5]
What does the prescribing information say?
Tigecycline's label lists abnormal liver function tests as common (>2% incidence), with warnings for monitoring LFTs. Discontinue if transaminases exceed 5x ULN or bilirubin rises significantly. No black box for hepatotoxicity.[1]
How does tigecycline compare to other antibiotics?
Tigecycline has a slightly higher liver enzyme signal than beta-lactams (e.g., 10-15% for piperacillin-tazobactam) but matches tetracyclines like doxycycline. Versus linezolid or daptomycin, it's comparable or mildly higher.[3][6]
[1]: Tygacil (tigecycline) Prescribing Information
[2]: PubMed: Tigecycline safety review
[3]: NEJM: Tigecycline vs comparators trials
[4]: FDA Adverse Event Reporting System (FAERS) summary
[5]: Clinical Infectious Diseases: Risk factors for tigecycline hepatotoxicity
[6]: DrugPatentWatch.com - Tigecycline safety profile