Proper Use

Drug information provided by: Merative, Micromedex®

Take this medicine exactly as directed by your doctor. Do not take it more often, and do not take it for a longer time than your doctor ordered.

Do not change the dose or stop using this medicine without checking first with your doctor. When your supply of this medicine is running low, contact your doctor or pharmacist ahead of time. Do not allow yourself to run out of this medicine.

This medicine comes with a patient information leaflet and patient instructions. Read and follow the instructions carefully. Ask your doctor if you have any questions. Read it again each time you refill your prescription in case there is new information. You should talk to your doctor if you have any questions.

Keep taking efavirenz for the full time of treatment, even if you begin to feel better. It is also important that you continue taking all other medicines for HIV infection your doctor has instructed you to take. Efavirenz will not work if it is taken alone. It must be taken with other HIV medicines.

This medicine works best when there is a constant amount in the blood. To help keep blood levels constant, do not miss any doses. Also, it is best to take the doses at evenly spaced times during the day. For example, if you or your child are taking one dose per day, try to take it at the same time each day. If you need help planning the best times to take your medicine, check with your doctor.

Take this medicine on an empty stomach at bedtime.

Swallow the capsule or tablet whole with water. Do not break, crush, or chew the tablet.

If you or your child are unable to swallow the capsule whole:

  • Wash and dry your hands well.
  • Gather a teaspoon, a spoon for stirring, and a small clean container such as a small cup or bowl.
  • Open the capsule and pour the contents into 1 to 2 teaspoons of soft food (including applesauce, grape jelly, or yogurt) in the container. You may instead mix the medicine into infant formula in the container.
  • Using the small spoon, gently mix the capsule contents and food together. It will not completely dissolve. Mixture will look grainy but should not be lumpy.
  • The mixture should be taken or given within 30 minutes. Use the small spoon to give or take the mixture. If you use the oral syringe, place the tip into the container. Slowly pull back on the plunger and draw up the mixture.
  • Place the tip of the syringe in your baby's mouth along the inner cheek. Slowly push on the plunger to give your baby all of the mixture.
  • Add another 2 teaspoons of the soft food into the empty container and gently stir with the small spoon to mix any remaining capsule contents. Give or take the mixture with the spoon or syringe as above.
  • Do not eat anything else for 2 hours after taking this medicine mixed with food or formula.

Tell your doctor if you take rifampin (Rifadin®, Rifamate®, Rifater®) or voriconazole (Vfend®). Your dose may need to be changed.


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For HIV infection:
    • For oral dosage form (capsules):
      • Adults and children 3 months of age and older or weighing 40 kilograms or more—600 milligrams (mg) once a day.
      • Children 3 months of age and older weighing less than 40 kg—Dose is base on body weight and must be determined by your doctor.
        • Weighing 32.5 kg to less than 40 kg—400 mg (two 200 mg capsules) once a day.
        • Weighing 25 kg to less than 32.5 kg—350 mg (one 200 mg and three 50 mg capsules) once a day.
        • Weighing 20 kg to less than 25 kg—300 mg (one 200 mg and two 50 mg capsules) once a day.
        • Weighing 15 kg to less than 20 kg—250 mg (one 200 mg and one 50 mg capsules) once a day.
        • Weighing 7.5 kg to less than 15 kg—200 mg once a day.
        • Weighing 5 kg to less than 7.5 kg—150 mg (three 50 mg capsules) once a day.
        • Weighing 3.5 kg to less than 5 kg—100 mg (two 50 mg capsules) once a day.
      • Children younger than 3 months of age and weighing less than 3.5 kg—Use is not recommended.
    • For oral dosage form (tablets):
      • Adults and children weighing 40 kilograms (kg) or more—600 milligrams (mg) once a day, taken with other medicines.
      • Children weighing less than 40 kg—Use of capsule is recommended.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.