See also Warning and How to Use sections.
Headache, nausea, diarrhea, dizziness, tiredness, or trouble sleeping may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
As your immune system gets stronger, it can begin to fight off infections you already had, possibly causing disease symptoms to come back. You could also have symptoms if your immune system becomes overactive. This reaction may happen at any time (soon after starting HIV treatment or many months later). Get medical help right away if you have any serious symptoms, including: unexplained weight loss, severe tiredness, muscle aches/weakness that doesn't go away, headaches that are severe or don't go away, joint pain, numbness/tingling of the hands/feet/arms/legs, vision changes, signs of infection (such as fever, chills, swollen lymph nodes, trouble breathing, cough, non-healing skin sores), signs of an overactive thyroid (such as irritability, nervousness, heat intolerance, fast/pounding/irregular heartbeat, bulging eyes, unusual growth in the neck/thyroid known as a goiter), signs of a certain nerve problem known as Guillain-Barre syndrome (such as unsteadiness, loss of coordination, trouble swallowing/speaking/chewing, trouble moving your eyes).
Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as depression, anxiety), easy bruising/bleeding, signs of anemia (such as unusual tiredness, fast breathing, pale skin, fast heartbeat).
Get medical help right away if you have any very serious side effects, including: signs of pancreatitis (such as nausea, vomiting, stomach/abdominal/back pain, fever).
Rarely, this medication has caused severe (sometimes fatal) liver problems and a buildup of lactic acid in the blood (lactic acidosis). These serious side effects may occur more often in women and obese patients. Get medical help right away if you have any of the following serious symptoms, including: symptoms of liver problems (such as nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine), symptoms of lactic acidosis (such as deep/rapid breathing, drowsiness, nausea/vomiting).
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.