Atovaquone Suspension and Sustiva

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.

Efavirenz may significantly reduce the blood levels of atovaquone, which may make the medication less effective in treating your condition. Talk to your doctor if you have any questions or concerns. Your doctor may already be aware of the interaction, but has determined that this is the best course of treatment for you and has taken appropriate precautions and is monitoring you closely for any potential complications. 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 with efavirenz may significantly decrease the plasma concentrations of atovaquone and proguanil. The mechanism of interaction has not been established, but may involve induction of the glucuronidation of atovaquone and the CYP450 2C19-mediated metabolism of proguanil. According to an open-label study from the Netherlands, HIV patients stabilized on antiretroviral regimens containing efavirenz (600 mg once daily; n=20) had significantly lower plasma concentrations of atovaquone and proguanil compared to healthy volunteers (n=18) following a single 250 mg/100 mg dose of atovaquone/proguanil. Specifically, atovaquone systemic exposure (AUC) was 75% lower and proguanil AUC was 43% lower in the efavirenz group than in the control group. In another study, 10 HIV-infected patients taking efavirenz-containing antiretroviral regimens had atovaquone AUC that was approximately 47% lower when given atovaquone 750 mg twice daily for 14 days and 44% lower when given atovaquone 1500 mg twice daily for 14 days compared to 10 HIV-infected controls not taking antiretroviral therapy given the same dosages of atovaquone. Only half of the subjects receiving efavirenz and atovaquone 750 mg twice daily had an average atovaquone concentration greater than 15 mcg/mL, which has previously been associated with successful treatment of Pneumocystis jiroveci pneumonia, compared to all subjects in the control group. Moreover, just 2 of 10 subjects receiving efavirenz with atovaquone 750 mg twice daily achieved an average atovaquone concentration greater than 18.5 mcg/mL, a concentration that has previously been associated with successful treatment of Toxoplasma encephalitis, compared to 9 of 10 controls.

MANAGEMENT: Given the potential for treatment failure when atovaquone or atovaquone/proguanil is administered with efavirenz, concomitant use is not recommended.

Atovaquone Suspension

Generic Name: atovaquone

Brand name: Mepron

Synonyms: Atovaquone

What is Atovaquone Suspension?

Sustiva

Generic Name: efavirenz

Brand name: Sustiva

Synonyms: n.a.

What is Sustiva?