Itraconazole; Ketoconazole; Posaconazole/Efavirenz
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
Efavirenz may speed up how quickly your liver processes your antifungal medicine.
What might happen:
Your antifungal may not work as well.
What you should do about this interaction:
Make sure your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Your doctor may want to change your medicine.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Sustiva (efavirenz) US prescribing information. Bristol-Myers Squibb Company August, 2012.
2.Sustiva (efavirenz) Canadian prescribing information. Bristol-Myers Squibb January 8, 2007.
3.Sustiva (efavirenz) UK summary of product characteristics. Bristol-Myers Squibb Pharmaceuticals Ltd January 26, 2007.
4.Atripla (efavirenz/emtricitabine/tenofovir disoproxil fumarate) US prescribing information. Gilead Sciences, Inc. October, 2013.
5.Sriwiriyajan S, Mahatthanatrakul W, Ridtitid W, Jaruratanasirikul S. Effect of efavirenz on the pharmacokinetics of ketoconazole in HIV-infected patients. Eur J Clin Pharmacol 2007 May;63(5):479-83.
6.Noxafil (posaconazole) US prescribing information. Merck & Co. Inc March, 2014.