Kaletra and Vfend Injection

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.

Using ritonavir and voriconazole is not recommended. Call your doctor if you notice that voriconazole is not working or if your infection worsens. 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.

CONTRAINDICATED: Coadministration with ritonavir may significantly decrease or increase the plasma concentrations of voriconazole. The proposed mechanism may involve ritonavir-mediated induction of voriconazole metabolism via the CYP450 isoenzymes 2C19 and 2C9. Voriconazole is primarily metabolized via CYP450 2C19, and to a lesser extent, by CYP450 2C9 and 3A4. In a randomized, placebo-controlled study in healthy adult male subjects (n=29), high-dose ritonavir (400 mg twice daily for 10 days) administered with oral voriconazole (400 mg twice daily for one day, then 200 mg twice daily for 9 days) decreased the mean steady-state voriconazole peak plasma concentration (Cmax) and systemic exposure (area under the concentration-time curve from 0 to 12 hours, or AUC (0-12)) by 68% and 83%, respectively. Low-dose ritonavir (100 mg every 12 hours for 10 days) administered with the same oral voriconazole regimen in healthy adult male subjects (n=17) decreased the mean steady-state Cmax and AUC (0-12) of voriconazole by 24% and 39%, respectively. However, the opposite effect may occur in patients who are poor metabolizers of CYP450 2C19. The net effect in these patients may be increased exposure to voriconazole via ritonavir-mediated inhibition of CYP450 3A4. In the high-dose ritonavir study above, one subject had an increased voriconazole exposure of 2.5-fold. In the low-dose ritonavir study, 4 subjects showed increased voriconazole exposure; three of these had slight increases (10% to 42%), but one subject had an approximately 3.5-fold increase in voriconazole exposure. Although voriconazole is also considered a strong inhibitor of CYP450 3A4 and an inhibitor of CYP450 2C19 and 2C9, the pharmacokinetics of high-dose ritonavir were not significantly affected by voriconazole; mean steady-state Cmax and AUC (0-12) of low-dose ritonavir decreased slightly by approximately 24% and 14%, respectively, during coadministration with oral voriconazole.

MANAGEMENT: The use of voriconazole in combination with high-dose ritonavir (400 mg or more every 12 hours) is considered contraindicated. Coadministration of voriconazole and low-dose ritonavir (100 mg every 12 hours) should also be avoided, unless the benefit justifies the risk.

Kaletra

Generic Name: lopinavir / ritonavir

Brand name: Kaletra

Synonyms: n.a.

What is Kaletra?

Vfend Injection

Generic Name: voriconazole

Brand name: Vfend, Vfend

Synonyms: Vfend

What is Vfend Injection?