Pifeltro and Rifabutin

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Rifabutin may significantly reduce the blood levels of doravirine, which may make the medication less effective in treating HIV infection. Additionally, it may lead to development of viral resistance to this and various other HIV medications that are currently used for treatment. Doravirine should not be started until at least 4 weeks after discontinuing rifabutin. If they are used together, a dosage increase of doravirine is normally recommended. Talk to your doctor if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

ADJUST DOSE: Coadministration with rifabutin may significantly decrease the plasma concentrations of doravirine. The mechanism is rifabutin induction of doravirine metabolism via CYP450 3A4. When a single 100 mg dose of doravirine was administered with rifabutin 300 mg once daily in 12 study subjects, doravirine peak plasma concentration (Cmax) did not change, but systemic exposure (AUC) and trough plasma concentration (C24hr) decreased by an average of 50% and 68%, respectively, compared to doravirine administered alone. Reduced efficacy of doravirine may occur.

MANAGEMENT: When used with rifabutin, doravirine dosage should be increased to 100 mg twice daily (approximately 12 hours apart) for the duration of rifabutin coadministration. Otherwise, doravirine should not be initiated until at least 4 weeks after cessation of rifabutin.

Pifeltro

Generic Name: doravirine

Brand name: Pifeltro

Synonyms: n.a.

What is Pifeltro?

Rifabutin

Generic Name: rifabutin

Brand name: Mycobutin

Synonyms: n.a.

What is Rifabutin?