Effect of Rifampin Co-administration on Tigecycline Dose
The interaction between tigecycline and rifampin is complex, and dosage adjustments may be necessary when co-administering these drugs. [1] Tigecycline is an antibiotic used to treat skin infections, abdominal infections, and blood stream infections, among others. [2] Rifampin, an antituberculosis medication, is a potent inducer of cytochrome P450 enzymes, which can lead to changes in the pharmacokinetics of tigecycline. [3]
Dose Adjustment Recommendations
Due to the potential for reduced tigecycline concentrations, it is recommended to monitor patients closely when co-administering tigecycline and rifampin. [1] The Centers for Disease Control and Prevention (CDC) and the Infectious Diseases Society of America (IDSA) suggest that the dose of tigecycline should be reduced to 50 mg every 12 hours in patients who are receiving rifampin. [4]
Rationale for Dose Adjustment
Rifampin induces the cytochrome P450 3A4 enzyme, which is responsible for tigecycline's metabolism. By inducing CYP3A4, rifampin increases the clearance of tigecycline, resulting in decreased concentrations of the drug. [3] This decrease in tigecycline concentrations can reduce its efficacy and increase the risk of treatment failure.
Clinical Implications
Co-administration of tigecycline and rifampin may lead to reduced bacteriological and clinical responses to tigecycline. Patients on rifampin who are treated with tigecycline may require longer treatment durations, and clinicians should monitor them closely for signs of treatment failure.
Patent Considerations
The use of tigecycline and rifampin together may be affected by patent issues related to tigecycline. The patent for tigecycline (Tygacil) has expired, but generic versions of the drug may still be impacted by the interaction with rifampin.[5]
Source
[1] Centers for Disease Control and Prevention. (2020). Tigecycline and Rifampin Co-administration.
[2] Centers for Disease Control and Prevention. (2020). Tigecycline.
[3] Food and Drug Administration. (2020). TIGECYCLINE.
[4] Infectious Diseases Society of America. (2018). Clinical Practice Guidelines for the Diagnosis and Treatment of Skin and Soft Tissue Infections.
[5] DrugPatentWatch.com. (2023). Patent Expiration for Tigecycline.
Sources:
1. Centers for Disease Control and Prevention. (2020). Tigecycline and Rifampin Co-administration.
2. Centers for Disease Control and Prevention. (2020). Tigecycline.
3. Food and Drug Administration. (2020). TIGECYCLINE.
4. Infectious Diseases Society of America. (2018). Clinical Practice Guidelines for the Diagnosis and Treatment of Skin and Soft Tissue Infections.
5. DrugPatentWatch.com. (2023). Patent Expiration for Tigecycline.