While minor, some of these side effects may occur. They are as follows; Diarrhea, nausea, vomiting, dizziness, lightheadedness, drowsiness, and stomach upset, loss of appetite, trouble sleeping, headache, or dry mouth may occur. However if any of these persist or worsen, it’s best to speak with your doctor right away.
This medication may cause saliva, urine, or sweat to turn a dark color. This effect is harmless, but your clothes may be stained.
Some people taking this medication have fallen asleep suddenly during their usual daily activities (such as talking on the phone, driving). In some cases, sleep occurred without any feelings of drowsiness beforehand. This sleep effect may occur anytime during treatment with this medication even if you have used this medication for a long time. If you experience increased sleepiness or fall asleep during the day, do not drive or do other possibly dangerous activities until you have discussed this effect with your doctor. Your risk of this sleep effect is increased by using alcohol or other medications that can make you drowsy. See also Precautions section.
Tell your doctor right away if you have any serious side effects, including: new/worsening movements you can't control/spasms, greatly increased eye blinking/twitching, fainting, diarrhea that doesn't stop, vision changes (such as blurred vision), eye pain, severe stomach/abdominal pain, black/tarry stools, vomit that looks like coffee grounds, muscle pain/tenderness/weakness, signs of kidney problems (such as change in the amount of urine), mental/mood changes (such as confusion, hallucinations, thoughts of suicide), signs of infection (such as sore throat that doesn't go away), easy bleeding/bruising, unusual tiredness, tingling of the hands/feet, unusual strong urges (such as increased gambling, increased sexual urges).
Get medical help right away if you have any very serious side effects, including: chest pain.
Suddenly stopping or reducing the dose of this medication may rarely cause a very serious condition called neuroleptic malignant syndrome (NMS). Get medical help right away if you have any of the following symptoms: fever, unusual muscle stiffness, severe confusion, sweating, fast/irregular heartbeat, rapid breathing
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.