Based on the information provided, there is no specific mention of how other drug interactions directly affect the dosage of Tigecycline. However, it is crucial to note that Tigecycline, a broad-spectrum antibiotic sold under the brand name Tygacil, can interact with other medications, potentially impacting its efficacy or increasing the risk of adverse effects [2].

The prescribing information on Medscape states that Tigecycline is primarily eliminated unchanged by the biliary system, and therefore, dosage adjustment based on renal function is not necessary [2]. However, no information is available regarding dosage adjustments due to drug-drug interactions.

A PubMed article from 2008 discusses the pharmacokinetics and safety of Tigecycline, but it does not specifically address the issue of dosage adjustments due to drug interactions [3].

In summary, while there is no direct information on how other drug interactions affect Tigecycline's dosage, it is essential to be aware of potential drug-drug interactions, which may impact the drug's efficacy or increase the risk of adverse effects [2]. It is always recommended to consult a healthcare professional or pharmacist for personalized advice regarding drug interactions and dosages.

Sources:
[1] <https://www.drugpatentwatch.com/p/tradename/TIGECYCLINE>
[2] <https://reference.medscape.com/drug/tygacil-tigecycline-342527>
[3] <https://pubmed.ncbi.nlm.nih.gov/18576904/>