It is very important that your doctor check the progress of you or your child at regular visits, to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.
Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. You should not become pregnant while you are taking this medicine and for 12 weeks after stopping it. If you think you have become pregnant while using the medicine, tell your doctor right away. Your doctor may want you to join a pregnancy registry for patients taking an anti-HIV medicine.
Do not use this medicine if you or your child are also using Atripla®, bepridil (Vascor®), cisapride (Propulsid®), ergot medicines (e.g., dihydroergotamine, ergonovine, ergotamine, methylergonovine, Bellergal-S®, Cafergot®, DHE 45®, Ergostat®, Sansert®, or Wigraine®), midazolam (Versed®), pimozide (Orap®), triazolam (Halcion®), or voriconazole (Vfend®).
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (e.g., St. John's wort) or vitamin supplements.
This medicine may cause some people to become dizzy, lightheaded, drowsy, or less alert than they are normally. Even if taken at bedtime, it may cause some people to feel drowsy or less alert on arising. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert.
Check with your doctor before taking efavirenz with alcohol or other medicines that affect the central nervous system (CNS). The use of alcohol or other medicines that affect the CNS with efavirenz may worsen the side effects of this medicine, such as dizziness, poor concentration, drowsiness, unusual dreams, and trouble with sleeping. Some examples of medicines that affect the CNS are antihistamines or medicine for allergies or colds; sedatives, tranquilizers, or sleeping medicine; medicine for depression; medicine for anxiety; prescription pain medicine or narcotics; medicine for attention deficit and hyperactivity disorder; medicine for seizures or barbiturates; muscle relaxants; or anesthetics, including some dental anesthetics.
This medicine may increase your risk of having serious mental or behavioral problems. Tell your doctor if you or your child develop any mood changes, strange thoughts, or any unusual behavior while you are using this medicine.
Liver problems may occur while you are using this medicine. Stop using this medicine and check with your doctor right away if you or your child are having more than one of these symptoms: abdominal pain or tenderness; clay-colored stools; dark urine; a fever; a headache; itching; loss of appetite; nausea and vomiting; skin rash; swelling of the feet or lower legs; unusual tiredness or weakness; or yellow eyes or skin.
This medicine may increase the level of cholesterol and fats in your blood. If this condition occurs, your doctor may give you a medicine to lower the cholesterol and fats. Talk to your doctor if you have concerns.
When you or your child start taking HIV medicines, your immune system may get stronger. If or your child you have certain infections, such as pneumonia or tuberculosis, you may notice new symptoms when your body tries to fight them. If this occurs, be sure to tell your doctor right away.
Efavirenz may cause you or your child to have excess body fat. Tell your doctor if you or your child notice changes in your body shape, such as an increased amount of fat in the upper back and neck, or around the chest and stomach area. You might also lose fat from the legs, arms, and face.
This medicine will not keep you from giving HIV to your partner during sex. Make sure you understand this and practice safe sex, even if your partner also has HIV, by using a latex condom or other barrier method. This medicine will also not keep you from giving HIV to other people if they are exposed to your blood. Do not re-use or share needles with anyone.
Birth control pills may not work as well while you are using efavirenz. Use an additional form of birth control along with your pills while you are taking this medicine and for 12 weeks after stopping it to keep from getting pregnant. Other forms of birth control include condoms, diaphragms, or contraceptive foams or jellies.
Stop using this medicine and check with your doctor right away if you or your child develop a skin rash; blistering, peeling, or loosening of the skin; red skin lesions; sores or ulcers on the skin; or fever or chills while you or your child are using this medicine.
Tell the doctor in charge that you or your child are taking this medicine before you have any medical tests. The results of some tests may be affected by this medicine.