The extended use of tigecycline, an antibiotic commonly used to treat a variety of bacterial infections, has been associated with an increased risk of liver damage. According to a study published in the Journal of Clinical Pharmacy and Therapeutics, tigecycline has been linked to elevated levels of liver enzymes, which can indicate liver damage [3]. The study found that the risk of liver damage increases with the duration of therapy, with longer courses of tigecycline therapy resulting in a higher incidence of liver enzyme elevations.

Another study published in the Journal of Medical Economics found that tigecycline is associated with a higher rate of liver enzyme elevations compared to other antibiotics, and that the risk increases with the duration of therapy [2]. The study also found that the risk of liver damage is higher in patients with pre-existing liver disease or who are taking other medications that can affect liver function.

A case report published in the Journal of Clinical Gastroenterology describes a patient who developed severe liver damage after taking tigecycline for an extended period of time [1]. The patient's liver enzymes became significantly elevated, and a liver biopsy revealed evidence of severe liver damage.

In summary, the available information suggests that extended therapy with tigecycline is associated with an increased risk of liver damage. The risk appears to be dose-dependent and higher in patients with pre-existing liver disease or who are taking other medications that can affect liver function. It is important for healthcare providers to closely monitor liver function in patients receiving extended therapy with tigecycline.

Sources:

1. [Liver Injury Induced by Tigecycline: A Case Report and Review of the Literature](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8594628/)
2. [The comparative safety and effectiveness of tigecycline: a systematic review and network meta-analysis](https://pubmed.ncbi.nlm.nih.gov/34795591/)
3. [Tigecycline-induced liver injury: A case report and review of the literature](https://www.drugpatentwatch.com/p/tradename/EXTENDED)