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.
Severe. These medicines may interact and cause very harmful effects and are usually not taken together. 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 voriconazole. Voriconazole may slow down how quickly your liver processes efavirenz.
What might happen:
Your voriconazole may not work as well at treating your infection. You may have more side effects than normal from your efavirenz.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know right away that you are taking these medicines together. Your doctor may want to change your medicines. Let your doctor know if you experience any drowsiness, dizziness, or trouble sleeping.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 March, 2015.
2.Vfend (voriconazole) US prescribing information. Pfizer Inc. February, 2015.
3.Atripla (efavirenz/emtricitabine/tenofovir disoproxil fumarate) UK summary of product characteristics. Gilead Sciences Ltd September 11, 2008.
4.Atripla (efavirenz/emtricitabine/tenofovir disoproxil fumarate) US prescribing information. Gilead Sciences, Inc. February, 2016.