Based on the available information, it is possible for long-term usage of Tigecycline to lead to liver issues.

Tigecycline is an antibiotic, used to treat a variety of bacterial infections, and is sold under the brand name Tygacil. According to the drug's official FDA label, liver function abnormalities have been reported in patients receiving Tigecycline [1]. These abnormalities include increases in liver enzymes, which can indicate liver damage or inflammation.

A study published by the National Institutes of Health (NIH) states that Tigecycline has been associated with a higher risk of liver enzyme elevations compared to other antibiotics [2]. The study also notes that the risk of liver enzyme elevations increases with longer durations of therapy.

Furthermore, Medscape's drug reference for Tigecycline states that liver function tests should be obtained at baseline and periodically during treatment, and dosage adjustments may be necessary in patients with hepatic impairment [3].

In summary, based on the available information, long-term usage of Tigecycline may increase the risk of liver issues, as indicated by elevated liver enzymes. It is important for healthcare providers to monitor liver function in patients receiving Tigecycline, especially during long-term therapy.

Sources:

1. <https://www.drugpatentwatch.com/p/tradename/TIGECYCLINE>
2. <https://www.ncbi.nlm.nih.gov/books/NBK547888/>
3. <https://reference.medscape.com/drug/tygacil-tigecycline-342527>