Nausea, stomach upset, cramps, loss of appetite, diarrhea, dry mouth, headache, nervousness, dizziness, trouble sleeping, sweating, weight loss, irritability, and restlessness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medicine because he or she 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.

This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high.

Tell your doctor right away if you have any serious side effects, including: signs of blood flow problems in the fingers or toes (such as coldness, numbness, pain, or skin color changes), unusual wounds on the fingers or toes, mental/mood/behavior changes (such as agitation, aggression, mood swings, depression, hallucinations, abnormal thoughts/behavior, thoughts of suicide), uncontrolled movements, muscle twitching/shaking, outbursts of words/sounds, change in sexual ability/interest, swelling ankles/feet, extreme tiredness, significant unexplained weight loss, frequent/prolonged erections (in males).

Get medical help right away if you have any very serious side effects, including: shortness of breath, chest/jaw/left arm pain, severe headache, fainting, fast/pounding/irregular heartbeat, seizures, weakness on one side of the body, slurred speech, confusion, blurred vision.

This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.