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What is efavirenz?

Efavirenz (also called Sustiva® or DMP-266) is used to treat infection caused by the human immunodeficiency virus (HIV). This medicine is one of a group called non-nucleoside reverse transcriptase inhibitors (NNRTIs). Efavirenz can slow down how soon you will see symptoms or slow the damage caused by HIV, but it cannot cure HIV infection. This medicine is offered as 50-mg, 100-mg, and 200-mg capsules. A liquid form of efavirenz may also be used.

How to give efavirenz

  • This medicine is taken once a day, usually at bedtime. It must be taken every day.
  • Efavirenz can be taken with or without food. Taking the medicine right after you have eaten a meal may help prevent upset stomach.

Possible side effects of efavirenz

  • Headache
  • Unusual dreams
  • Feeling dizzy or drowsy
  • Trouble concentrating
  • Diarrhea
  • Rash

These are the most common side effects, but there may be others. Please report all side effects to the doctor or nurse.

In case of a severe side effect or reaction, call the doctor, nurse or pharmacist at 595-3300. If you are outside the Memphis area, dial toll-free 1-866-2STJUDE (1-866-278-5833), and press 0 once the call is connected.

Special instructions for efavirenz

  • Store efavirenz capsules and liquid at room temperature.
  • Women must not become pregnant while they are taking efavirenz. Women who are old enough to become pregnant should talk to their doctor, nurse, or pharmacist about methods of birth control that work well. If you use pills for birth control, you should use a second method of birth control (such as a condom) while taking efavirenz.
  • Efavirenz may affect the way other medicines work. These medicines include:
    • Clarithromycin
    • Indinavir
    • Oral contraceptives (birth control pills)
    • Rifabutin
    • Saquinavir.
  • Some medicines can affect the way efavirenz works. These medicines include:
    • Rifampin
    • St. John’s wort
  • Always tell the doctor if you are taking these medicines, or if you start taking any new medicines while you are taking efavirenz.


This document is not intended to take the place of the care and attention of your personal physician or other professional medical services. Our aim is to promote active participation in your care and treatment by providing information and education. Questions about individual health concerns or specific treatment options should be discussed with your physician.

St. Jude complies with health care-related federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, or sex.

ATTENTION: If you speak another language, assistance services, free of charge, are available to you. Call 1-866-278-5833 (TTY: 1-901-595-1040).

ATENCIÓN: si habla español, tiene a su disposición servicios gratuitos de asistencia lingüística. Llame al 1-866-278-5833 (TTY: 1-901-595-1040).

تنبيه: إذا كنت تتحدث باللغة العربية فيمكنك الاستعانة بخدمات المساعدة اللغوية المتوفرة لك مجانا. .يرجى الاتصال بالرقم. 5833-278-866-1  (الهاتف النصي: 1040-595-901-1).