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Fanapt Side Effects

Generic Name: iloperidone

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

In Summary

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

For the Consumer

Applies to iloperidone: oral tablet

In addition to its needed effects, some unwanted effects may be caused by iloperidone (the active ingredient contained in Fanapt). In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when 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 from a lying or sitting position suddenly
  • 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
  • wheezing
  • 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

Minor Side Effects

Some of the side effects that can occur with iloperidone may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

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 kit, oral tablet

Nervous system

Common (1% to 10%): Dizziness, somnolence, extrapyramidal disorder, tremor, akathisia, dyskinesia
Uncommon (0.1% to 1%): Bradykinesia, dystonia, parkinsonism, paresthesia, vertigo, psychomotor hyperactivity, restlessness, amnesia
Rare (less than 0.1%): Restless leg syndrome[Ref]


Very common (10% or more): Tachycardia (up to 12%)
Common (1% to 10%): Palpitations, orthostatic hypotension, hypotension
Rare (less than 0.1%): Arrhythmia, atrioventricular block first degree, cardiac failure including congestive and acute, edema
Frequency not reported: QT prolongation[Ref]

In an open-label QTc study of 160 patients with schizophrenia or schizoaffective disorder, use of iloperidone 12 mg twice a day was associated with a QT prolongation of 9 msec. When iloperidone 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]


Common (1% to 10%): Nausea, dry mouth, abdominal discomfort, diarrhea
Uncommon (0.1% to 1%): Gastritis, salivary hypersecretion, fecal incontinence, mouth ulceration
Rare (less than 0.1%): Aphthous stomatitis, duodenal ulcer, hiatus hernia, hyperchlorhydria, lip ulceration, reflux esophagitis, stomatitis[Ref]


The most commonly reported adverse reactions included dizziness, dry mouth, fatigue, nasal congestion, orthostatic hypotension, somnolence, tachycardia, and increased weight.[Ref]


Common (1% to 10%): Nasal congestion, dyspnea, nasopharyngitis, upper respiratory tract infection

Uncommon (0.1% to 1%): Epistaxis, asthma, rhinorrhea, sinus congestion, nasal dryness
Rare (less than 0.1%): Dry throat, sleep apnea syndrome, dyspnea exertional[Ref]


Common (1% to 10%): Blurred vision, conjunctivitis
Uncommon (0.1% to 1%): Dry eye, blepharitis, eyelid edema, eye swelling, lenticular opacities, cataract, hyperemia (including conjunctival), nystagmus[Ref]


Common (1% to 10%): Arthralgia, musculoskeletal stiffness, myalgia, muscle spasms
Rare (less than 0.1%): Torticollis[Ref]


Common (1% to 10%): Rash[Ref]


Common (1% to 10%): Erectile dysfunction, urinary incontinence, ejaculation failure
Uncommon (0.1% to 1%): Dysuria, pollakiuria, enuresis, testicular pain, amenorrhea
Rare (less than 0.1%): Menstruation irregular, menorrhagia, metrorrhagia, postmenopausal hemorrhage, prostatitis
Frequency not reported: Priapism
Postmarketing reports: Retrograde ejaculation[Ref]


Common (1% to 10%): Restlessness, aggression, delusion
Uncommon (0.1% to 1%): Hostility, libido decreased, paranoia, anorgasmia, confusional state, mania catatonia, mood swings, panic attack, obsessive-compulsive disorder, bulimia nervosa, delirium, polydipsia, psychogenic, impulse-control disorder, major depression[Ref]


Uncommon (0.1% to 1%): Nephrolithiasis
Very rare (less than 0.01%): Acute renal failure[Ref]


Common (1% to 10%): Weight decreased, weight increased
Uncommon (0.1% to 1%): Increased appetite, dehydration, hypokalemia, fluid retention
Frequency not reported: Blood sugar elevations[Ref]


Uncommon (0.1% to 1%): Anemia, iron deficient anemia, decreased hematocrit, decreased hemoglobin, increased neutrophil count
Rare (less than 0.1%): Leukopenia[Ref]


Uncommon (0.1% to 1%): Breast pain
Rare (less than 0.1%): Gynecomastia, hypothyroidism[Ref]


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


Common (1% to 10%): Lethargy, fatigue
Uncommon (0.1% to 1%): Tinnitus[Ref]


Frequency not reported: Hypersensitivity to include pruritus and urticaria
Postmarketing reports: Anaphylaxis, angioedema, throat tightness, oropharyngeal swelling, swelling of the face, lips, mouth, and tongue, rash


Postmarketing reports: Pituitary adenoma


1. "Product Information. Fanapt (iloperidone)." Vanda Pharmaceuticals Inc, Rockville, MD.

Not all side effects for Fanapt may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.