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Fanapt Side Effects

Generic name: iloperidone

Medically reviewed by Last updated on Feb 19, 2023.

Note: This document contains side effect information about iloperidone. Some dosage forms listed on this page may not apply to the brand name Fanapt.


Common side effects of Fanapt include: dizziness, drowsiness, tachycardia, weight gain, sedated state, and xerostomia. Other side effects include: death, diarrhea, fatigue, nasal congestion, and orthostatic hypotension. Continue reading for a comprehensive list of adverse effects.

Applies to iloperidone: oral tablet.


Oral route (Tablet)

Elderly patients with dementia-related psychosis treated with atypical antipsychotic drugs are at an increased risk of death. Iloperidone is not approved for use in patients with dementia-related psychosis.

Serious side effects of Fanapt

Along with its needed effects, iloperidone (the active ingredient contained in Fanapt) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking iloperidone:

More common

  • Fast, pounding, or irregular heartbeat or pulse

Less common

  • Blurred vision
  • body aches or pain
  • chills
  • cold sweats
  • confusion
  • cough
  • difficult or labored breathing
  • difficulty with moving
  • difficulty with speaking
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • drooling
  • ear congestion
  • fever
  • headache
  • inability to sit still
  • loss of balance control
  • loss of voice
  • muscle pain or stiffness
  • muscle trembling, jerking, or stiffness
  • nasal congestion
  • need to keep moving
  • pain in the joints
  • restlessness
  • runny nose
  • shakiness in the legs, arms, hands, or feet
  • shortness of breath
  • shuffling walk
  • sneezing
  • sore throat
  • stiffness of the limbs
  • sweating
  • tightness in the chest
  • trembling or shaking of the hands or feet
  • twitching, twisting, uncontrolled repetitive movements of the tongue, lips, face, arms, or legs
  • uncontrolled movements, especially of the face, neck, and back
  • unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness


  • Abdominal or stomach fullness
  • aching or discomfort in the lower legs or sensation of crawling in the legs
  • actions that are out of control
  • aggressive or angry
  • agitation
  • anxiety
  • attack, assault, or force
  • back pain
  • black, tarry stools
  • bloody nose
  • burning while urinating
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • chest pain or discomfort
  • coma
  • confusion as to time, place, or person
  • constipation
  • convulsions
  • decrease in the amount of urine
  • decrease in the frequency of urination
  • decrease in urine volume
  • decreased awareness or responsiveness
  • decreased urination
  • decreased weight
  • depression
  • difficult or painful urination
  • difficulty in passing urine (dribbling)
  • difficulty with walking
  • dilated neck veins
  • dizziness
  • dry mouth
  • dry skin and hair
  • extreme thirst
  • extremely high fever or body temperature
  • fainting
  • false beliefs that cannot be changed by facts
  • fast, shallow breathing
  • feeling cold
  • frequent urination
  • gaseous abdominal pain
  • groin pain
  • hair loss
  • hoarseness or husky voice
  • holding false beliefs that cannot be changed by fact
  • hostility
  • inability to move the eyes
  • increased blinking or spasms of the eyelid
  • increased thirst
  • irregular breathing
  • irritability
  • lightheadedness
  • loss of appetite
  • loss of bladder control
  • mimicry of speech or movements
  • mood swings
  • muscle aching or cramping
  • muscle spasms
  • muscle twitching
  • nausea or vomiting
  • nervousness
  • noisy breathing
  • noisy, rattling breathing
  • numbness or tingling in the hands, feet, or lips
  • pale, clammy skin
  • peculiar postures or movements, mannerisms, or grimacing
  • pounding, slow heartbeat
  • rapid breathing
  • rapid weight gain
  • recurrent fever
  • restlessness
  • seizures
  • severe sleepiness
  • slow movement
  • slow reflexes
  • sore throat
  • sore tongue
  • sores, ulcers, or white spots on the lips or in the mouth
  • sticking out of tongue
  • stupor
  • sunken eyes
  • swelling
  • swelling of the face, ankles, fingers, feet, or lower legs
  • swollen glands
  • swollen joints
  • swollen, tender prostate
  • talking, feeling, and acting with excitement
  • thirst
  • troubled breathing at rest
  • troubled breathing with exertion
  • uncontrolled twisting movements of the neck, trunk, arms, or legs
  • unusual bleeding or bruising
  • unusual excitement, nervousness, or restlessness
  • unusual facial expressions
  • weight gain
  • wrinkled skin
  • yellow eyes or skin

Other side effects of Fanapt

Some side effects of iloperidone may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Diarrhea
  • sleepiness or unusual drowsiness

Less common

  • Abdominal or stomach discomfort
  • not able to ejaculate semen
  • rash
  • stuffy nose


  • Absent, missed, or irregular menstrual periods
  • blindness
  • blurred vision
  • breast pain
  • burning feeling in the chest or stomach
  • burning upper abdominal pain
  • canker sores
  • continuing ringing or buzzing or other unexplained noise in the ears
  • decreased interest in sexual intercourse
  • decreased vision
  • delusions of persecution, mistrust, suspiciousness, or combativeness
  • dry eyes
  • feeling of constant movement of self or surroundings
  • hearing loss
  • inability to have or keep an erection
  • increase in blood flow to the whites of the eyes
  • increased appetite
  • increased watering of the mouth
  • indigestion
  • irregular menstruation
  • irritation or soreness of the mouth
  • longer or heavier menstrual periods
  • loss in sexual ability, desire, drive, or performance
  • loss of bowel control
  • loss of memory
  • normal menstrual bleeding occurring earlier, possibly lasting longer than expected
  • problems with memory
  • redness, swelling, or itching of the eyelids
  • sensation of spinning
  • stomach upset
  • stopping of menstrual bleeding
  • swelling of the breasts or breast soreness in both females and males
  • swelling or inflammation of the mouth
  • tenderness in the stomach area
  • uncontrolled eye movements

For Healthcare Professionals

Applies to iloperidone: oral tablet.


The most commonly reported side effects included dizziness, somnolence, and tachycardia.[Ref]

Nervous system

Very common (10% or more): Dizziness (up to 20%), somnolence (up to 15%)

Common (1% to 10%): Akathisia, dyskinesia, dystonia, extrapyramidal disorder, lethargy, tremor

Uncommon (0.1% to 1%): Amnesia, bradykinesia, difficulty in walking, nystagmus, paresthesia, parkinsonism, psychomotor hyperactivity, vertigo

Rare (0.01% to 0.1%): Restless legs syndrome[Ref]


Very common (10% or more): Tachycardia (up to 12%)

Common (1% to 10%): Hypotension, orthostatic hypotension, palpitations

Uncommon (0.1% to 1%): Edema due to cardiac disease, general edema, pitting edema

Rare (0.01% to 0.1%): Acute cardiac failure, arrhythmia, congestive cardiac failure, first degree atrioventricular block[Ref]

In an open-label QTc study of 160 patients with schizophrenia or schizoaffective disorder, use of 12 mg twice a day was associated with a QT prolongation of 9 msec. When this drug was administered concomitantly with paroxetine 20 mg once a day (CYP450 2D6-inhibitor) or ketoconazole 200 mg twice a day (CYP450 3A4-inhibitor), the mean QTc interval prolongation from baseline increased to 19 msec.[Ref]


Very common (10% or more): Dry mouth (up to 10%), nausea (up to 10%)

Common (1% to 10%): Abdominal discomfort, diarrhea

Uncommon (0.1% to 1%): Fecal incontinence, gastritis, mouth ulceration, salivary hypersecretion

Rare (0.01% to 0.1%): Aphthous stomatitis, duodenal hernia, hiatus hernia, hyperchlorhydria, lip ulceration, reflux esophagitis, stomatitis

Postmarketing reports: Lip swelling, mouth swelling, oropharyngeal swelling, tongue swelling[Ref]


Common (1% to 10%): Dyspnea, nasal congestion, nasopharyngitis, upper respiratory tract infection

Uncommon (0.1% to 1%): Asthma, epistaxis, nasal dryness, rhinorrhea, sinus congestion

Rare (0.01% to 0.1%): Dry throat, exertional dyspnea, sleep apnea syndrome

Postmarketing reports: Throat swelling[Ref]


Common (1% to 10%): Aggression, delusion, restlessness

Uncommon (0.1% to 1%): Anorgasmia, bulimia nervosa, catatonia, confusional state, delirium, hostility, impulse-control disorder, libido decreased, major depression, mania, mood swings, obsessive-compulsive disorder, panic attack, paranoia[Ref]


Common (1% to 10%): Allergic conjunctivitis, blurred vision, conjunctivitis

Uncommon (0.1% to 1%): Blepharitis, cataract, conjunctival hyperemia, dry eye, eyelid edema, eye swelling, hyperemia, lenticular opacities[Ref]


Common (1% to 10%): Ejaculation failure, erectile dysfunction, urinary incontinence

Uncommon (0.1% to 1%): Amenorrhea, breast pain, dysuria, enuresis, pollakiuria, testicular pain

Rare (0.01% to 0.1%): Menorrhagia, metrorrhagia, menstruation irregular, postmenopausal hemorrhage, prostatitis, urinary retention

Postmarketing reports: Retrograde ejaculation[Ref]


Common (1% to 10%): Muscle spasms, musculoskeletal stiffness, myalgia

Rare (0.01% to 0.1%): Torticollis[Ref]


Common (1% to 10%): Weight decreased, weight increased

Uncommon (0.1% to 1%): Dehydration, fluid retention, hypokalemia, increased appetite, polydipsia psychogenic, thirst[Ref]


Common (1% to 10%): Fatigue

Uncommon (0.1% to 1%): Hyperthermia, tinnitus[Ref]


Uncommon (0.1% to 1%): Nephrolithiasis

Rare (0.01% to 0.1%): Acute renal failure[Ref]


Common (1% to 10%): Rash

Postmarketing reports: Facial swelling, pruritus, urticaria[Ref]


Uncommon (0.1% to 1%): Anemia, hematocrit decreased/lowered, hemoglobin decreased, iron deficiency anemia, neutrophil count increased

Rare (0.01% to 0.1%): Leukopenia[Ref]


Uncommon (0.1% to 1%): Hypothyroidism

Rare (0.01% to 0.1%): Gynecomastia[Ref]


Uncommon (0.1% to 1%): Cholelithiasis[Ref]


Postmarketing reports: Anaphylaxis, angioedema, hypersensitivity reactions[Ref]


1. Product Information. Fanapt (iloperidone). Vanda Pharmaceuticals Inc. 2009.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.