Important changes to US prescribing information for efavirenz
5 February 2007. Related: Antiretrovirals.
The efavirenz (Sustiva) package insert in the US has been updated to include drug-drug interaction information regarding coadministration of efavirenz with rifampin, diltiazem, itraconazole, voriconazole, atorvastatin, pravastatin, simvastatin, pimozide and bepridil.
The Clinical Pharmacology section (Tables 1 and 2) were revised to include the results of drug-drug interactions studies with diltiazem, itraconazole, voriconazole, atorvastatin, pravastatin, and simvastatin.
The CONTRAINIDCATION section was revised to state Sustiva should not be administered concurrently with bepridil, pimozide and standard doses of voriconazole.
The PRECAUTION: Drug Interaction section (Tables 5 and 6) were updated to include information regarding coadministration of efavirenz with rifampin, diltiazem (and other calcium channel blockers), itraconazole, ketoconazole, voriconazole, pimozide and bepridil.
The Dosing and Administration section was updated to include dosing information for the co administration of efavirenz and voriconazole. Specifically, if efavirenz is coadministered with voriconazole, the voriconazole maintenance dose should be increased to 400 mg every 12 hours and the efavirenz dose should be decreased to 300 mg once daily using the capsule formulation (three 100-mg capsules or one 200-mg and one 100-mg capsule). Efavirenz tablets should not be broken.
For further details including reference table please see the full article:
http://www.fda.gov/oashi/aids/listserve/listserve2007.html#13107
Source: Food and Drug Administration
An archive of past list serve announcements is available on the FDA web site:
http://www.fda.gov/oashi/aids/listserve/archive.html