Fanapt Side Effects Center

Last updated on RxList: 10/13/2020
Fanapt Side Effects Center

What Is Fanapt?

Fanapt (iloperidone) is an antipsychotic medication used to treat schizophrenia.

What Are Side Effects of Fanapt?

Common side effects of Fanapt include:

Tell your doctor if you have rare but serious side effects of Fanapt including:

Dosage for Fanapt

The recommended starting dose of Fanapt is 1 mg twice daily. The target dose range is 6-12 mg twice daily.

What Drugs, Substances, or Supplements Interact with Fanapt?

Fanapt may interact with other medicines that make you sleepy (such as cold or allergy medicine, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression, or anxiety), arsenic trioxide, droperidol, antibiotics, antidepressants, anti-malaria medications, heart rhythm medicines, medicine to prevent or treat nausea and vomiting, other medicines to treat psychiatric disorders, migraine headache medicines, or narcotics. Tell your doctor all medications you use. During pregnancy, Fanapt should be used only when prescribed. Do not stop taking this medication unless directed by your doctor.

Fanapt During Pregnancy and Breastfeeding

Babies born to mothers who have used this drug during the last 3 months of pregnancy may infrequently develop symptoms including muscle stiffness or shakiness, drowsiness, feeding/breathing difficulties, or constant crying. If you notice symptoms in your newborn during their first month, tell the doctor. It is unknown if this medication passes into breast milk. Consult your doctor before breastfeeding.

Additional Information

Our Fanapt (iloperidone) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Schizophrenia is the most disabling mental illness. See Answer
Fanapt Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

High doses or long-term use of iloperidone can cause a serious movement disorder that may not be reversible. The longer you use iloperidone, the more likely you are to develop this disorder, especially if you are an older adult.

Call your doctor at once if you have:

  • fast or pounding heartbeats, fluttering in your chest;
  • a light-headed feeling, like you might pass out;
  • uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement);
  • tremors, slow muscle movement, muscles pain or stiffness;
  • confusion, agitation, thoughts of hurting yourself;
  • loss of bladder control;
  • penis erection that is painful or lasts 4 hours or longer;
  • high blood sugar--increased thirst, increased urination, dry mouth, fruity breath odor;
  • low white blood cell counts--fever, chills, sore throat, mouth sores, skin sores, cough, trouble breathing; or
  • severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out;

Older adults may be more likely to have side effects from this medicine.

Common side effects may include:

  • weight gain;
  • dizziness, drowsiness, tired feeling;
  • dry mouth, stuffy nose; or
  • fast heart rate.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Schizophrenia: Symptoms, Types, Causes, Treatment See Slideshow
Fanapt Professional Information


Clinical Studies Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trial of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. The information below is derived from a clinical trial database for FANAPT consisting of 3229 patients exposed to FANAPT at doses of 10 mg/day or greater, for the treatment of schizophrenia. Of these, 999 received FANAPT for at least 6 months, with 657 exposed to FANAPT for at least 12 months. All of these patients who received FANAPT were participating in multiple-dose clinical trials. The conditions and duration of treatment with FANAPT varied greatly and included (in overlapping categories), open-label and double-blind phases of studies, inpatients and outpatients, fixed-dose and flexible-dose studies, and short-term and longer-term exposure.

The information presented in these sections was derived from pooled data from 4 placebo-controlled, 4- or 6week, fixed- or flexible-dose studies in patients who received FANAPT at daily doses within a range of 10 to 24 mg (n=874).

Adverse Reactions Occurring At An Incidence Of 2% Or More Among FANAPT-Treated Patients And More Frequent Than Placebo

Table 7 enumerates the pooled incidences of adverse reactions that were spontaneously reported in four placebo-controlled, 4- or 6-week, fixed- or flexible-dose studies, listing those reactions that occurred in 2% or more of patients treated with FANAPT in any of the dose groups, and for which the incidence in FANAPT-treated patients in any dose group was greater than the incidence in patients treated with placebo.

Table 7: Percentage of Adverse Reactions in Short-Term, Fixed- or Flexible-Dose, Placebo-Controlled Trials in Adult Patients*

Body System or Organ Class Dictionary-derived Term Placebo % (N=587) FANAPT 10-16 mg/day % (N=483) FANAPT 20-24 mg/day % (N=391)
Body as a Whole
  Arthralgia 2 3 3
  Fatigue 3 4 6
  Musculoskeletal Stiffness 1 1 3
  Weight Increased 1 1 9
Cardiac Disorders
  Tachycardia 1 3 12
Eye Disorders
  Vision Blurred 2 3 1
Gastrointestinal Disorders
  Nausea 8 7 10
  Dry Mouth 1 8 10
  Diarrhea 4 5 7
  Abdominal Discomfort 1 1 3
  Nasopharyngitis 3 4 3
  Upper Respiratory Tract Infection 1 2 3
Nervous System Disorders
  Dizziness 7 10 20
  Somnolence 5 9 15
  Extrapyramidal Disorder 4 5 4
  Tremor 2 3 3
  Lethargy 1 3 1
Reproductive System
  Ejaculation Failure < 1 2 2
  Nasal Congestion 2 5 8
  Dyspnea < 1 2 2
  Rash 2 3 2
Vascular Disorders
  Orthostatic Hypotension 1 3 5
  Hypotension < 1 < 1 3
* Table includes adverse reactions that were reported in 2% or more of patients in any of the FANAPT dose groups and which occurred at greater incidence than in the placebo group. Figures rounded to the nearest integer.

Dose-Related Adverse Reactions In Clinical Trials

Based on the pooled data from 4 placebo-controlled, 4- or 6-week, fixed- or flexible-dose studies, adverse reactions that occurred with a greater than 2% incidence in the patients treated with FANAPT, and for which the incidence in patients treated with FANAPT 20-24 mg/day were twice than the incidence in patients treated with FANAPT 10-16 mg/day were: abdominal discomfort, dizziness, hypotension, musculoskeletal stiffness, tachycardia, and weight increased.

Common And Drug-Related Adverse Reactions In Clinical Trials

Based on the pooled data from 4 placebo-controlled, 4- or 6-week, fixed- or flexible-dose studies, the following adverse reactions occurred in ≥ 5% incidence in the patients treated with FANAPT and at least twice the placebo rate for at least 1 dose: dizziness, dry mouth, fatigue, nasal congestion, somnolence, tachycardia, orthostatic hypotension, and weight increased. Dizziness, tachycardia, and weight increased were at least twice as common on 20-24 mg/day as on 10-16 mg/day.

Extrapyramidal Symptoms (EPS) In Clinical Trials

Pooled data from the 4 placebo-controlled, 4- or 6-week, fixed- or flexible-dose studies provided information regarding EPS. Adverse event data collected from those trials showed the following rates of EPS-related adverse events as shown in Table 8 .

Table 8: Percentage of EPS Compared to Placebo

Adverse Event Term Placebo (%)
FANAPT 10-16 mg/day (%)
FANAPT 20-24 mg/day (%)
All EPS events 11.6 13.5 15.1
Akathisia 2.7 1.7 2.3
Bradykinesia 0 0.6 0.5
Dyskinesia 1.5 1.7 1.0
Dystonia 0.7 1.0 0.8
Parkinsonism 0 0.2 0.3
Tremor 1.9 2.5 3.1

Adverse Reactions Associated With Discontinuation Of Treatment In Clinical Trials

Based on the pooled data from 4 placebo-controlled, 4- or 6-week, fixed- or flexible-dose studies, there was no difference in the incidence of discontinuation due to adverse events between FANAPT-treated (5%) and placebo-treated (5%) patients. The types of adverse events that led to discontinuation were similar for the FANAPT- and placebo-treated patients.

Demographic Differences In Adverse Reactions In Clinical Trials

An examination of population subgroups in the 4 placebo-controlled, 4- or 6-week, fixed- or flexible-dose studies did not reveal any evidence of differences in safety on the basis of age, gender or race.

Laboratory Test Abnormalities In Clinical Trials

There were no differences between FANAPT and placebo in the incidence of discontinuation due to changes in hematology, urinalysis, or serum chemistry.

In short-term placebo-controlled trials (4- to 6-weeks), there were 1.0% (13/1342) iloperidone-treated patients with hematocrit at least one time below the extended normal range during post-randomization treatment, compared to 0.3% (2/585) on placebo. The extended normal range for lowered hematocrit was defined in each of these trials as the value 15% below the normal range for the centralized laboratory that was used in the trial.

Other Reactions During The Pre-marketing Evaluation Of FANAPT

The following is a list of MedDRA terms that reflect adverse reactions in patients treated with FANAPT at multiple doses ≥ 4 mg/day during any phase of a trial with the database of 3210 FANAPT-treated patients. All reported reactions are included except those already listed in Table 7, or other parts of the Adverse Reactions  (6), those considered in the Warnings and Precautions (5), those reaction terms which were so general as to be uninformative, reactions reported in fewer than 3 patients and which were neither serious nor life-threatening, reactions that are otherwise common as background reactions, and reactions considered unlikely to be drug related.

Reactions are further categorized by MedDRA system organ class and listed in order of decreasing frequency according to the following definitions: frequent adverse events are those occurring in at least 1/100 patients (only those not listed in Table 7 appear in this listing); infrequent adverse reactions are those occurring in 1/100 to 1/1000 patients; rare events are those occurring in fewer than 1/1000 patients.

Blood and Lymphatic Disorders: Infrequent - anemia, iron deficiency anemia; Rare - leukopenia

Cardiac Disorders: Frequent - palpitations; Rare - arrhythmia, atrioventricular block first degree, cardiac failure (including congestive and acute)

Ear and Labyrinth Disorders: Infrequent - vertigo, tinnitus

Endocrine Disorders: Infrequent - hypothyroidism

Eye Disorders: Frequent - conjunctivitis (including allergic); Infrequent - dry eye, blepharitis, eyelid edema, eye swelling, lenticular opacities, cataract, hyperemia (including conjunctival)

Gastrointestinal Disorders: Infrequent - gastritis, salivary hypersecretion, fecal incontinence, mouth ulceration; Rare - aphthous stomatitis, duodenal ulcer, hiatus hernia, hyperchlorhydria, lip ulceration, reflux esophagitis, stomatitis

General Disorders and Administrative Site Conditions: Infrequent - edema (general, pitting, due to cardiac disease), difficulty in walking, thirst; Rare - hyperthermia

Hepatobiliary Disorders: Infrequent - cholelithiasis

Investigations: Frequent: weight decreased; Infrequent - hemoglobin decreased, neutrophil count increased, hematocrit decreased

Metabolism and Nutrition Disorders: Infrequent - increased appetite, dehydration, hypokalemia, fluid retention

Musculoskeletal and Connective Tissue Disorders: Frequent - myalgia, muscle spasms; Rare - torticollis

Nervous System Disorders: Infrequent - paresthesia, psychomotor hyperactivity, restlessness, amnesia, nystagmus; Rare - restless legs syndrome

Psychiatric Disorders: Frequent - restlessness, aggression, delusion; Infrequent - 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

Renal and Urinary Disorders: Frequent - urinary incontinence; Infrequent - dysuria, pollakiuria, enuresis, nephrolithiasis; Rare - urinary retention, renal failure acute

Reproductive System and Breast Disorders: Frequent - erectile dysfunction; Infrequent - testicular pain, amenorrhea, breast pain; Rare - menstruation irregular, gynecomastia, menorrhagia, metrorrhagia, postmenopausal hemorrhage, prostatitis.

Respiratory, Thoracic and Mediastinal Disorders: Infrequent - epistaxis, asthma, rhinorrhea, sinus congestion, nasal dryness; Rare - dry throat, sleep apnea syndrome, dyspnea exertional

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of FANAPT: retrograde ejaculation and hypersensitivity reactions (including anaphylaxis; angioedema; throat tightness; oropharyngeal swelling; swelling of the face, lips, mouth, and tongue; urticaria; rash; and pruritus). Because these reactions were reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Read the entire FDA prescribing information for Fanapt (Iloperidone Tablets)

© Fanapt Patient Information is supplied by Cerner Multum, Inc. and Fanapt Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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