See also How to Use section.
Drowsiness, dizziness, lightheadedness, dry mouth, tiredness, stuffy nose, and weight gain may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
This medication may cause a serious drop in blood pressure, especially when starting or increasing the dose. Dizziness and lightheadedness can increase the risk of falling. Get up slowly when rising from a sitting or lying position.
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.
Tell your doctor right away if you have any serious side effects, including: drooling/trouble swallowing, signs of infection (such as cough that doesn't go away, fever), shaking (tremor), muscle spasms, interrupted breathing during sleep.
Rarely, this medication may cause face/muscle twitching and uncontrollable movements (tardive dyskinesia). In some cases, this condition may be permanent. Tell your doctor right away if you develop any uncontrollable movements such as lip smacking, mouth puckering, tongue thrusting, chewing, or unusual arm/leg movements.
This drug may rarely make your blood sugar rise, which can cause or worsen diabetes. Weight gain from this drug may increase the risk of this side effect. Tell your doctor right away if you have symptoms of high blood sugar such as increased thirst/urination. If you already have diabetes, check your blood sugar regularly as directed and share the results with your doctor. Your doctor may need to adjust your diabetes medication, exercise program, or diet.
In rare cases, iloperidone may increase your level of a certain substance made by the body (prolactin). For females, this increase in prolactin may result in unwanted breast milk, missed/stopped periods, or difficulty becoming pregnant. For males, it may result in decreased sexual ability, inability to produce sperm, or enlarged breasts. If you develop any of these symptoms, tell your doctor right away.
Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.
Get medical help right away if you have any very serious side effects, including: fainting, fast/irregular heartbeat, seizures, severe dizziness, chest pain.
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, muscle stiffness/pain/tenderness/weakness, severe tiredness, severe confusion, sweating, fast/irregular heartbeat, dark urine, signs of kidney problems (such as change in the amount of urine).
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.
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.