Tigecycline is a broad-spectrum antibiotic, used to treat various bacterial infections, including skin and abdominal infections, and community-acquired pneumonia [1]. Its metabolism plays a significant role in determining the appropriate dosage for patients.

Tigecycline undergoes hepatic metabolism through glucuronidation and dehydrogenation [2]. This metabolic pathway results in minimal renal clearance of the drug, making dosage adjustments unnecessary for patients with renal impairment [2]. However, patients with hepatic impairment may require dose adjustments due to the drug's primary metabolic route [2].

The FDA-approved dosage for tigecycline is 100 mg intravenously as an initial dose, followed by 50 mg every 12 hours [3]. However, for patients with severe hepatic impairment, a lower dosage of 25 mg every 12 hours is recommended [3].

In summary, tigecycline's hepatic metabolism significantly impacts its dosing. While renal impairment does not necessitate dose adjustments, patients with hepatic impairment may require lower dosages due to the drug's primary metabolic route.

Sources:
[1] "Tigecycline." National Library of Medicine, <https://medlineplus.gov/druginfo/meds/a607045.html>.
[2] "Tigecycline." DrugPatentWatch.com, <https://www.drugpatentwatch.com/drugs/tigecycline>.
[3] "TIGECYCLINE injection, for intravenous use." Food and Drug Administration, <https://www.accessdata.fda.gov/drugsatfda_docs/label/2010/021867s013s014lbl.pdf>.