Does tigecycline dosage change with elevated liver enzymes?
Tigecycline, an IV glycylcycline antibiotic for complicated infections, requires no dosage adjustment in patients with mild to moderate hepatic impairment (Child-Pugh A or B). For severe hepatic impairment (Child-Pugh C), the loading dose stays the same at 100 mg, but maintenance doses drop to 25 mg every 12 hours.[1][2]
What counts as elevated liver enzymes for tigecycline?
Elevated enzymes alone (e.g., high ALT/AST) do not trigger adjustments unless they indicate Child-Pugh C cirrhosis. Tigecycline dosing follows liver function classification, not isolated enzyme levels. In pre-existing impairment:
| Hepatic Status | Loading Dose | Maintenance Dose |
|---------------|--------------|------------------|
| Normal (Child-Pugh A/B) | 100 mg | 50 mg q12h |
| Severe (Child-Pugh C) | 100 mg | 25 mg q12h |
No adjustment needed for end-stage renal disease or dialysis.[1][3]
How does tigecycline affect liver enzymes?
Tigecycline commonly raises liver enzymes (ALT/AST increases in up to 25% of patients), but this is usually reversible and does not require dose changes during treatment. Monitor LFTs; discontinue if drug-induced liver injury is suspected.[2][4]
Why the caution in severe liver disease?
Tigecycline undergoes extensive hepatic metabolism and biliary excretion. In Child-Pugh C, clearance drops ~40%, raising exposure risk without dose reduction.[1][5] No data exists for acute liver failure.
What do guidelines say?
FDA and EMA labels specify the above adjustments. IDSA guidelines for infections (e.g., intra-abdominal) note hepatic dosing but prioritize alternatives like carbapenems if severe impairment complicates therapy.[2][6]
Sources:
[1] Tigecycline FDA Label: https://www.accessdata.fda.gov/drugsatfdadocs/label/2010/021821s021lbl.pdf
[2] EMA Summary of Product Characteristics: https://www.ema.europa.eu/en/documents/product-information/tygacil-epar-product-informationen.pdf
[3] DrugPatentWatch.com (tigecycline patents/approvals): https://www.drugpatentwatch.com/p/tradename/TYGACIL
[4] Clinical Pharmacology Review: https://www.ncbi.nlm.nih.gov/books/NBK571421/
[5] Meagher et al., Pharmacotherapy 2003: https://pubmed.ncbi.nlm.nih.gov/14507049/
[6] IDSA Guidelines (e.g., cIAI): https://www.idsociety.org/practice-guideline/intra-abdominal-infections/