It is very important that your doctor check the progress of you or your child at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.
This medicine may cause a severe allergic reaction in some patients. This reaction usually occurs within 6 weeks after the medicine is started but may occur at any time. If untreated, it can lead to severe low blood pressure and even death. Stop taking this medicine and check with your doctor immediately if you or your child notice sudden fever, skin rash, diarrhea, nausea, stomach pain, vomiting, or a feeling of unusual tiredness or illness, cough, shortness of breath, or sore throat.
When you begin taking this medicine, you or your child will be given a warning card which describes symptoms of severe allergic reactions that may be caused by abacavir. The warning card also provides information about how to treat these allergic reactions. For your safety, you should carry the warning card with you at all times.
Do not stop using this medicine unless your doctor tells you to do so. If you stop using this medicine for any reason, do not start taking it again without talking first to your doctor.
If you must stop using abacavir because of an allergic reaction, you should never use the medicine again. Return the unused medicine to your doctor or pharmacist. A worse reaction, possibly even death, can occur if you use the medicine again. Tell your doctor right away if you or your child have ever taken abacavir, especially if you have experienced an allergic reaction to it in the past.
Two rare but serious reactions to this medicine are lactic acidosis (too much acid in the blood) and liver toxicity, which includes an enlarged liver. These are more common if you are female, very overweight (obese), or have been taking anti-HIV medicines for a long time. Call your doctor right away if you or your child have more than one of these symptoms: stomach discomfort or cramping; dark urine; decreased appetite; diarrhea; general feeling of discomfort; light-colored stools; muscle cramping or pain; nausea; unusual tiredness or weakness; trouble breathing; vomiting; or yellow eyes or skin.
When you start taking HIV medicines, your immune system may get stronger. If you or your child have certain infections that are hidden in your body, such as pneumonia or tuberculosis, you may notice new symptoms when your body tries to fight them. If this occurs, tell your doctor right away.
This medicine will not keep you from giving HIV to your partner during sex. Make sure you understand and practice safe sex, such as using latex condoms, even if your partner also has HIV. Do not share needles, toothbrushes, and razor blades with anyone.
This medicine may cause you 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; or a loss of fat from the legs, arms, and face.
This medicine may increase your risk of having a heart attack. This is more likely to occur if you smoke or already have heart disease, high blood pressure, or high cholesterol or fats in the blood. Call your doctor right away if you have chest pain or discomfort; nausea; pain or discomfort in the arms, jaw, back or neck; shortness of breath; sweating; or vomiting. These could be symptoms of a heart attack.
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 or vitamin supplements.