The recommended dosing frequency for tigecycline, an antibiotic used to treat various bacterial infections, is twice daily [1]. The typical dosage for adults is 100 mg intravenously (IV) every 12 hours [1].

For patients with severe hepatic impairment, a reduced dosage is recommended. The first dose should be 100 mg IV, followed by 50 mg every 12 hours [1].

It is important to note that tigecycline has a long half-life, which allows for less frequent dosing [2]. However, the efficacy of tigecycline may be lower compared to other antibiotics for certain types of infections [3].

Sources:
[1] "Tigecycline." Lexicomp Online, Wolters Kluwer Health, 2021, online.drugs.com/monograph/tigecycline/intravenous/main.
[2] "Tigecycline: a review of its use in the treatment of complicated skin and soft tissue infections and complicated intra-abdominal infections." Drugs, U.S. National Library of Medicine, Aug. 2006, www.ncbi.nlm.nih.gov/pubmed/16907495.
[3] "Tigecycline." DrugPatentWatch, 2021, drugpatentwatch.com/drugs/tigecycline.