Fosamprenavir Tablets and Kaletra Oral Solution

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.

Ask your doctor before using lopinavir together with fosamprenavir. Using these medications together may cause either drug to be less effective. Contact your doctor if your condition worsens. If your doctor prescribes these medications together, you may need a dose adjustment or special tests to safely use both medications. 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.

GENERALLY AVOID: Coadministration of fosamprenavir (prodrug of amprenavir) and lopinavir-ritonavir may result in decreased plasma concentrations of both amprenavir and lopinavir. The exact mechanism of interaction is unknown but apparently not mediated by ritonavir. In one study, 15 HIV patients given the combination had mean steady-state amprenavir and lopinavir plasma concentrations at 12 hours post-dose that were 31% and 39%, respectively, of those observed in 8 patients given amprenavir plus ritonavir (700 mg/100 mg twice a day) and 8 patients given lopinavir-ritonavir (400 mg-100 mg twice a day). The 12-hour systemic exposure (AUC) of amprenavir and lopinavir in combination was 36% and 52%, respectively, relative to that of the individual treatments. Dosage adjustments have been studied as a means to overcome the interaction. In 18 subjects, coadministration of lopinavir-ritonavir (533 mg-133 mg twice a day) and fosamprenavir (1400 mg twice a day) for 2 weeks resulted in acceptable lopinavir pharmacokinetics but amprenavir peak plasma concentration (Cmax), AUC, and trough plasma concentration (Cmin) that were still 13%, 26%, and 42% lower, respectively, than fosamprenavir plus ritonavir alone. When lopinavir-ritonavir (400 mg-100 mg twice a day) and fosamprenavir-ritonavir (700 mg-100 mg twice a day) were coadministered for 2 weeks, amprenavir Cmax, AUC and Cmin were lower by 58%, 63% and 65%, respectively, while lopinavir Cmax, AUC and Cmin were increased by 30%, 37% and 52%, respectively. Separating the fosamprenavir and lopinavir-ritonavir doses by 4 to 12 hours also has not been shown to eliminate the interaction.

MANAGEMENT: Appropriate dosages of the combination with respect to safety and efficacy have not been established. Given the risk of reduced viral susceptibility and resistance development associated with subtherapeutic antiretroviral drug levels, the combination of fosamprenavir and lopinavir-ritonavir should be avoided if possible.

Fosamprenavir Tablets

Generic Name: fosamprenavir

Brand name: Lexiva, Telzir

Synonyms: Fosamprenavir

What is Fosamprenavir Tablets?

Kaletra Oral Solution

Generic Name: lopinavir / ritonavir

Brand name: Kaletra

Synonyms: Kaletra

What is Kaletra Oral Solution?