Drowsiness, headache, and tiredness may occur. Less common side effects include problems sleeping, dry mouth, constipation, dizziness, and diarrhea. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Remember that your doctor has prescribed this medication 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.
Tell your doctor immediately if any of these unlikely but serious side effects occur: mental/mood changes (e.g., confusion, depression, thoughts of suicide, hallucinations, anxiety, agitation), decreased sexual ability, feelings of restlessness/agitation/jitteriness, mask-like facial expression, shuffling walk, drooling, uncontrolled shaking of the hands, twitching in the face, muscle spasms, weakness, trouble swallowing, uncontrollable movements of the mouth/face/hands, unusual nipple discharge, enlarged/tender breasts, unusual fluid retention (swelling), changes in menstruation in women, vision changes, slow or fast irregular heartbeat, fainting, increase in urination, inability to hold urine (incontinence).
Tell your doctor immediately if any of these rare but very serious side effects occur: signs of serious infection (e.g., high fever, persistent sore throat, severe chills), signs of liver problems (e.g., persistent nausea/vomiting, severe tiredness, yellowing eyes/skin, dark urine, severe stomach/abdominal pain).
This drug may infrequently cause a serious (sometimes fatal) nervous system problem (neuroleptic malignant syndrome). Seek immediate medical attention if you notice any of the following rare but very serious side effects: fever, rigid muscles, increased sweating, fast heartbeat, mental/mood changes, change in the amount of urine.
A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching, swelling, severe dizziness, trouble breathing.
These reactions are more common if you have asthma.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.