SIDE EFFECTS: Headache and trouble sleeping may occur. If these effects persist or worsen, notify your doctor. Very unlikely but report promptly: dark urine, yellowing of the eyes or skin, rapid breathing, change in amount of urine. Changes in body fat may occur while you are taking this medication (e.g., increased fat in the upper back and stomach areas, decreased fat in the arms and legs). The cause and long-term effects of these changes are unknown. Discuss the risks and benefits of therapy with your doctor, as well as the possible role of exercise to reduce this side effect. In the unlikely event you have an allergic reaction to this drug, seek immediate medical attention. Symptoms of an allergic reaction to this drug include: fever, nausea, vomiting, diarrhea, skin rash, extreme tiredness, achiness, stomach pain, swelling, trouble breathing, cough, sore throat. If you notice other effects not listed above, contact your doctor or pharmacist.

PRECAUTIONS: Tell your doctor your medical history, including: allergies (especially drug allergies), liver disease, alcohol dependence, diabetes. Limit alcohol intake, as it may intensify side effects of this drug. If you must stop using this drug due to an allergic reaction, never use the drug again or death could result. Consult MD and read the "Warning Card" for more details. If you stop using abacavir (e.g., forget to order a refill) even for a short time and then restart the drug, you have an increased chance of developing the very serious (possibly fatal) allergic reaction. Do not stop treatment unless specifically instructed to do so. Know the symptoms of this allergic reaction (see side effects section). Consult your doctor or pharmacist before restarting abacavir, and be sure you have easy access to medical care if you are restarting treatment. This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor. It is not known whether this drug is excreted into breast milk. Avoid breast-feeding because breast milk can transmit HIV. Consult your doctor or pharmacist before breast-feeding.

DRUG INTERACTIONS: Tell your doctor of all nonprescription and prescription medication you may use, especially of: drugs that cause liver problems (e.g., isoniazid)., lamivudine and tenofovir. Do not start or stop any medicine without doctor or pharmacist approval.