Iloperidone

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Fanapt: 1 mg, 2 mg, 4 mg, 6 mg, 8 mg, 10 mg, 12 mg

Fanapt Titration Pack: 1 mg (2s), 2 mg (2s), 4 mg (2s), and 6 mg (2s)

Pharmacology

Mechanism of Action

Iloperidone is a piperidinyl-benzisoxazole atypical antipsychotic with mixed D₂/5-HT₂ antagonist activity. It exhibits high affinity for 5-HT_2A, NE_α1, D₂, and D₃ receptors, low to moderate affinity for D₁, D₄, H₁, 5-HT_1A, 5-HT₆, and 5-HT₇ receptors, and no affinity for muscarinic receptors. The addition of serotonin antagonism to dopamine antagonism (classic neuroleptic mechanism) is thought to improve negative symptoms of psychoses and reduce the incidence of extrapyramidal side effects (Huttunen 1995). Iloperidone’s low affinity for histamine H₁ receptors may decrease the risk for weight gain and somnolence while its affinity for NE _α1/α2C may improve cognitive function but increase the risk for orthostasis (Arif 2011, Huttunen 1995, Nasrallah 2008).

Pharmacokinetics/Pharmacodynamics

Absorption

Well absorbed

Distribution

V_d: 1,340 to 2,800 L

Metabolism

Hepatic via carbonyl reduction, hydroxylation (CYP2D6) and O-demethylation (CYP3A4); forms active metabolites (P88 and P95)

Excretion

Active metabolites (P88 and P95): Urine (58% extensive metabolizers, 45% poor metabolizers); feces (20% extensive metabolizers, 22% poor metabolizers) (Sheehan 2010)

Iloperidone: <1% recovered unchanged in urine and feces (Sheehan 2010)

Time to Peak

Plasma: 2 to 4 hours

Half-Life Elimination

Extensive metabolizers: Iloperidone: 18 hours; P88: 26 hours; P95: 23 hours

Poor metabolizers: Iloperidone: 33 hours; P88: 37 hours; P95: 31 hours

Protein Binding

~97% iloperidone; ~92% active metabolites (P88 and P95)

Use in Specific Populations

Special Populations: Hepatic Function Impairment

Higher (2-fold) and more variable free drug exposure to the active metabolite P88 in patients with moderate hepatic impairment.

Use: Labeled Indications

Schizophrenia: Treatment of adults with schizophrenia

Use: Off Label

Psychosis/agitation associated with dementiayes

Based on the American Psychiatric Association practice guideline on the use of antipsychotics to treat agitation or psychosis in patients with dementia, antipsychotics, such as iloperidone, may be considered for the treatment of agitation and psychosis in certain patients with dementia; however, evidence for efficacy is modest and use should be limited to patients whose symptoms are dangerous, severe, or cause significant patient distress due to safety risks associated with antipsychotic use.

Contraindications

Hypersensitivity to iloperidone (eg, anaphylaxis, angioedema) or any component of the formulation

Dosage and Administration

Dosing: Adult

Schizophrenia: Oral: Initial: 1 mg twice daily; titrate to the recommended dosage range with dosage adjustments not to exceed 2 mg twice daily (4 mg daily) every 24 hours; recommended dosage range: 6 to 12 mg twice daily (maximum: 24 mg/day)

Note: Titrate dose to effect (to avoid orthostatic hypotensive effects); when reinitiating treatment after discontinuation (>3 days), follow initial titration schedule.

Dosage adjustment in patients receiving strong CYP2D6 inhibitors (eg, paroxetine, fluoxetine, quinidine) or strong CYP3A4 inhibitors (eg, ketoconazole, clarithromycin): Decrease iloperidone dose by 50%; when CYP2D6 inhibitor or CYP3A4 inhibitor is discontinued, return to previous dose.

Dosage adjustment in poor metabolizers of CYP2D6: Decrease iloperidone dose by 50%.

Discontinuation of therapy: The American Psychiatric Association (APA), Canadian Psychiatric Association (CPA), and World Federation of Societies of Biological Psychiatry (WFSBP) guidelines recommend gradually tapering antipsychotics to avoid withdrawal symptoms and minimize the risk of relapse (APA [Lehman 2004]; Cerovecki 2013; CPA [Addington 2005]; WFSBP [Hasan 2012]); risk for withdrawal symptoms may be highest with highly anti-cholinergic or dopaminergic antipsychotics (Cerovecki 2013). When stopping antipsychotic therapy in patients with schizophrenia, the CPA guidelines recommend a gradual taper over 6 to 24 months, and the APA guidelines recommend reducing the dose by 10% each month (APA [Lehman 2004]; CPA [Addington 2005]). Continuing anti-parkinsonism agents for a brief period after discontinuation may prevent withdrawal symptoms (Cerovecki 2013). When switching antipsychotics, 3 strategies have been suggested: cross-titration (gradually discontinuing the first antipsychotic while gradually increasing the new antipsychotic), overlap and taper (maintaining the dose of the first antipsychotic while gradually increasing the new antipsychotic, then tapering the first antipsychotic), and abrupt change (abruptly discontinuing the first antipsychotic and either increasing the new antipsychotic gradually or starting it at a treatment dose). Evidence supporting ideal switch strategies and taper rates is limited, and results are conflicting (Cerovecki 2013; Remington 2005).

Dosing: Geriatric

Refer to adult dosing.

Psychosis/agitation associated with dementia (off-label use): Oral: Initial: One-third to one-half the usual dose to treat psychosis in younger adults or the smallest available dosage. In patients without a clinically significant response after 4 weeks, taper and withdraw therapy. In patients with an adequate response, attempt to taper and withdraw therapy within 4 months, unless symptoms recurred with a previous taper attempt. Assess symptoms at least monthly during taper and for at least 4 months after withdrawal of therapy (APA [Reus 2016]).

Administration

Administer with or without food.

Storage

Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Protect from light and moisture.

Drug Interactions

Abiraterone Acetate: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Management: Avoid concurrent use of abiraterone with CYP2D6 substrates that have a narrow therapeutic index whenever possible. When concurrent use is not avoidable, monitor patients closely for signs/symptoms of toxicity. Consider therapy modification

Acetylcholinesterase Inhibitors (Central): May enhance the neurotoxic (central) effect of Antipsychotic Agents. Severe extrapyramidal symptoms have occurred in some patients. Monitor therapy

Ajmaline: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Monitor therapy

Alizapride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Amifampridine: Agents With Seizure Threshold Lowering Potential may enhance the neuroexcitatory and/or seizure-potentiating effect of Amifampridine. Monitor therapy

Amisulpride: Antipsychotic Agents may enhance the adverse/toxic effect of Amisulpride. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Avoid combination

Amphetamines: Antipsychotic Agents may diminish the stimulatory effect of Amphetamines. Monitor therapy

Antidiabetic Agents: Hyperglycemia-Associated Agents may diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy

Anti-Parkinson Agents (Dopamine Agonist): Antipsychotic Agents (Second Generation [Atypical]) may diminish the therapeutic effect of Anti-Parkinson Agents (Dopamine Agonist). Management: Consider using an alternative antipsychotic agent when possible in patients with Parkinson disease. If an atypical antipsychotic is necessary, consider using clozapine or quetiapine, which may convey the lowest interaction risk. Consider therapy modification

ARIPiprazole: CYP3A4 Inhibitors (Weak) may increase the serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy and/or indication. Consult full interaction monograph for specific recommendations. Monitor therapy

Asunaprevir: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Consider therapy modification

Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination

Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Consider therapy modification

Blood Pressure Lowering Agents: May enhance the hypotensive effect of Antipsychotic Agents (Second Generation [Atypical]). Monitor therapy

Brexanolone: CNS Depressants may enhance the CNS depressant effect of Brexanolone. Monitor therapy

Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Bromopride: May enhance the adverse/toxic effect of Antipsychotic Agents. Avoid combination

Bromperidol: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

Buprenorphine: CNS Depressants may enhance the CNS depressant effect of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine at lower doses in patients already receiving CNS depressants. Consider therapy modification

Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Chlormethiazole: May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Consider therapy modification

Chlorphenesin Carbamate: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

CloBAZam: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Monitor therapy

CYP2D6 Inhibitors (Moderate): May decrease the metabolism of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

CYP2D6 Inhibitors (Strong): May increase serum concentrations of the active metabolite(s) of Iloperidone. Specifically, concentrations of the metabolite P88 may be increased. CYP2D6 Inhibitors (Strong) may decrease serum concentrations of the active metabolite(s) of Iloperidone. Specifically, concentrations of the metabolite P95 may be decreased. CYP2D6 Inhibitors (Strong) may increase the serum concentration of Iloperidone. Management: Reduce iloperidone dose by half when administered with a strong CYP2D6 inhibitor. Consider therapy modification

CYP3A4 Inhibitors (Strong): May increase serum concentrations of the active metabolite(s) of Iloperidone. Specifically, concentrations of the metabolites P88 and P95 may be increased. CYP3A4 Inhibitors (Strong) may increase the serum concentration of Iloperidone. Management: Reduce iloperidone dose by half when administered with a strong CYP3A4 inhibitor. Consider therapy modification

Dacomitinib: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Management: Avoid concurrent use of dacomitinib with CYP2D6 subtrates that have a narrow therapeutic index. Consider therapy modification

Deutetrabenazine: May enhance the adverse/toxic effect of Antipsychotic Agents. Specifically, the risk for akathisia, parkinsonism, or neuroleptic malignant syndrome may be increased. Monitor therapy

Dimethindene (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Dofetilide: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Dofetilide. Monitor therapy

Doxylamine: May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended. Monitor therapy

Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Consider therapy modification

Esketamine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Flibanserin: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Flibanserin. Monitor therapy

Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Consider therapy modification

Guanethidine: Antipsychotic Agents may diminish the therapeutic effect of Guanethidine. Monitor therapy

Haloperidol: QT-prolonging Agents (Indeterminate Risk - Avoid) may enhance the QTc-prolonging effect of Haloperidol. Monitor therapy

HYDROcodone: CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Avoid concomitant use of hydrocodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

HydrOXYzine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Imatinib: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Iohexol: Agents With Seizure Threshold Lowering Potential may enhance the adverse/toxic effect of Iohexol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iohexol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic anticonvulsants. Consider therapy modification

Iomeprol: Agents With Seizure Threshold Lowering Potential may enhance the adverse/toxic effect of Iomeprol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iomeprol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic anticonvulsants. Consider therapy modification

Iopamidol: Agents With Seizure Threshold Lowering Potential may enhance the adverse/toxic effect of Iopamidol. Specifically, the risk for seizures may be increased. Management: Discontinue agents that may lower the seizure threshold 48 hours prior to intrathecal use of iopamidol. Wait at least 24 hours after the procedure to resume such agents. In nonelective procedures, consider use of prophylactic anticonvulsants. Consider therapy modification

Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

Lemborexant: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Lemborexant. Management: The maximum recommended dosage of lemborexant is 5 mg, no more than once per night, when coadministered with weak CYP3A4 inhibitors. Consider therapy modification

Lemborexant: May enhance the CNS depressant effect of CNS Depressants. Management: Dosage adjustments of lemborexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive CNS depressant effects. Close monitoring for CNS depressant effects is necessary. Consider therapy modification

Lithium: May enhance the neurotoxic effect of Antipsychotic Agents. Lithium may decrease the serum concentration of Antipsychotic Agents. Specifically noted with chlorpromazine. Monitor therapy

Lofexidine: May enhance the CNS depressant effect of CNS Depressants. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Monitor therapy

Lomitapide: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Lomitapide. Management: Patients on lomitapide 5 mg/day may continue that dose. Patients taking lomitapide 10 mg/day or more should decrease the lomitapide dose by half. The lomitapide dose may then be titrated up to a max adult dose of 30 mg/day. Consider therapy modification

Lumefantrine: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Mequitazine: Antipsychotic Agents may enhance the arrhythmogenic effect of Mequitazine. Management: Consider alternatives to one of these agents when possible. While this combination is not specifically contraindicated, mequitazine labeling describes this combination as discouraged. Consider therapy modification

Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Consider therapy modification

Methylphenidate: Antipsychotic Agents may enhance the adverse/toxic effect of Methylphenidate. Methylphenidate may enhance the adverse/toxic effect of Antipsychotic Agents. Monitor therapy

Metoclopramide: May enhance the adverse/toxic effect of Antipsychotic Agents. Avoid combination

MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Monitor therapy

MetyroSINE: May enhance the adverse/toxic effect of Antipsychotic Agents. Monitor therapy

Minocycline (Systemic): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

NiMODipine: CYP3A4 Inhibitors (Weak) may increase the serum concentration of NiMODipine. Monitor therapy

Opioid Agonists: CNS Depressants may enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination

Oxomemazine: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Panobinostat: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination

Peginterferon Alfa-2b: May decrease the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Peginterferon Alfa-2b may increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification

Perhexiline: CYP2D6 Substrates (High risk with Inhibitors) may increase the serum concentration of Perhexiline. Perhexiline may increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Pimozide: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Pimozide. Avoid combination

Piribedil: Antipsychotic Agents may diminish the therapeutic effect of Piribedil. Piribedil may diminish the therapeutic effect of Antipsychotic Agents. Management: Use of piribedil with antiemetic neuroleptics is contraindicated, and use with antipsychotic neuroleptics, except for clozapine, is not recommended. Avoid combination

QT-prolonging Agents (Highest Risk): QT-prolonging Agents (Indeterminate Risk - Avoid) may enhance the QTc-prolonging effect of QT-prolonging Agents (Highest Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Quinagolide: Antipsychotic Agents may diminish the therapeutic effect of Quinagolide. Monitor therapy

QuiNINE: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy

Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Monitor therapy

Serotonergic Agents (High Risk): May enhance the adverse/toxic effect of Antipsychotic Agents. Specifically, serotonergic agents may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotic Agents may enhance the serotonergic effect of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Monitor therapy

Sodium Oxybate: May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated. Consider therapy modification

Sulpiride: Antipsychotic Agents may enhance the adverse/toxic effect of Sulpiride. Avoid combination

Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification

Tapentadol: May enhance the CNS depressant effect of CNS Depressants. Management: Avoid concomitant use of tapentadol and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Tetrabenazine: May enhance the adverse/toxic effect of Antipsychotic Agents. Monitor therapy

Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Tetrahydrocannabinol and Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination

Triazolam: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Triazolam. Management: Consider triazolam dose reduction in patients receiving concomitant weak CYP3A4 inhibitors. Consider therapy modification

Trimeprazine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Ubrogepant: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Ubrogepant. Management: In patients taking weak CYP3A4 inhibitors, the initial and second dose (if needed) of ubrogepant should be limited to 50 mg. Consider therapy modification

Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification

Adverse Reactions

>10%:

Cardiovascular: Tachycardia (3% to 12%; dose-related)

Central nervous system: Dizziness (10% to 20%; dose-related), drowsiness (9% to 15%)

Endocrine & metabolic: Increased serum prolactin (26%), weight gain (9% to 18%; dose-related)

1% to 10%:

Cardiovascular: Orthostatic hypotension (3% to 5%), hypotension (3%; dose-related), palpitations (≥1%)

Central nervous system: Fatigue (4% to 6%), extrapyramidal reaction (4% to 5%), lethargy (3%), aggressive behavior (≥1%), delusions (≥1%), restlessness (≥1%), dystonia (≤1%)

Dermatologic: Skin rash (3%)

Endocrine & metabolic: Increased serum triglycerides (10%), increased serum cholesterol (4%), weight loss (≥1%)

Gastrointestinal: Nausea (10%), xerostomia (8% to 10%), diarrhea (5% to 7%), abdominal distress (3%; dose-related)

Genitourinary: Ejaculation failure (2%), erectile dysfunction (≥1%), urinary incontinence (≥1%)

Hematologic & oncologic: Decreased hematocrit (≤1%)

Neuromuscular & skeletal: Arthralgia (3%), muscle rigidity (3%; dose-related), tremor (3%), muscle spasm (≥1%), myalgia (≥1%)

Ophthalmic: Blurred vision (3%), conjunctivitis (≥1%; including allergic)

Respiratory: Nasal congestion (5% to 8%), nasopharyngitis (≤4%), upper respiratory tract infection (2% to 3%), dyspnea (2%)

Frequency not defined: Genitourinary: Priapism

<1%, postmarketing, and/or case reports: Abnormal gait, acute renal failure, amenorrhea, amnesia, anemia, anorgasmia, aphthous stomatitis, asthma, blepharitis, bradykinesia, bulimia nervosa, cardiac arrhythmia, cataract, catatonia, cholelithiasis, confusion, decreased hemoglobin, decreased libido, dehydration, delirium, dry nose, duodenal ulcer, dyspnea on exertion, dysuria, edema, emotional lability, epistaxis, eyelid edema, fecal incontinence, first degree atrioventricular block, fluid retention, gastritis, gastroesophageal reflux disease, gynecomastia, hiatal hernia, hostility, hyperacidity, hyperemia (including conjunctival), hyperglycemia, hypermenorrhea, hypersensitivity reaction (including anaphylaxis; angioedema; throat tightness; oropharyngeal swelling; swelling of the face, lips, mouth, and tongue; urticaria; pruritus), hyperthermia, hypokalemia, hypothyroidism, impulse control disorder, increased appetite, increased neutrophils, increased thirst, iron deficiency anemia, leukopenia, major depressive disorder, mania, mastalgia, menstrual disease, nephrolithiasis, neuroleptic malignant syndrome, nystagmus, obsessive compulsive disorder, oral mucosa ulcer, panic attack, paranoia, paresthesia, Parkinson’s disease, pollakiuria, polydipsia (psychogenic), postmenopausal bleeding, prolonged Q-T interval on ECG, prostatitis, psychomotor agitation, restless leg syndrome, retrograde ejaculation, rhinorrhea, salivation, sinus congestion, sleep apnea, stomatitis, swelling of eye, syncope, testicular pain, tinnitus, torticollis, urinary retention, uterine hemorrhage, vertigo, xerophthalmia

Warnings/Precautions

Concerns related to adverse effects:

• Altered cardiac conduction: May alter cardiac conduction and prolong the QTc interval; life-threatening arrhythmias have occurred with therapeutic doses of antipsychotics. Risks may be increased by conditions or concomitant medications which cause bradycardia, hypokalemia, and/or hypomagnesemia. Avoid use in combination with QTc-prolonging drugs. Avoid use in patients with congenital long QT syndrome, history of cardiac arrhythmia, recent MI, and/or uncompensated heart failure. Use caution in combination with drugs that inhibit iloperidone metabolism. Discontinue in patients found to have persistent QTc intervals >500 msec. Patients with symptoms of dizziness, palpitations, or syncope should receive further cardiac evaluation.
• Blood dyscrasias: Leukopenia, neutropenia, and agranulocytosis (sometimes fatal) have been reported in clinical trials and postmarketing reports with antipsychotic use; presence of risk factors (eg, pre-existing low WBC or history of drug-induced leuko-/neutropenia) should prompt periodic blood count assessment. Discontinue therapy at first signs of blood dyscrasias or if absolute neutrophil count <1,000/mm³.
• Cerebrovascular effects: An increased incidence of cerebrovascular effects (eg, transient ischemic attack, stroke), including fatalities, has been reported in placebo-controlled trials of antipsychotics for the unapproved use in elderly patients with dementia-related psychosis.
• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery or driving).
• Dyslipidemia: Undesirable alterations in lipids has been reported with atypical antipsychotics. Use with caution in patients with a pre-existing abnormal lipid profile.
• Esophageal dysmotility/aspiration: Antipsychotic use has been associated with esophageal dysmotility and aspiration; risk increases with age. Use with caution in patients at risk for aspiration pneumonia (eg, Alzheimer disease), particularly in patients >75 years (Herzig 2017; Maddalena 2004).
• Extrapyramidal symptoms: May cause extrapyramidal symptoms (EPS), including pseudoparkinsonism, acute dystonic reactions, akathisia, and tardive dyskinesia (risk of these reactions is generally much lower relative to typical/conventional antipsychotics; frequencies reported are similar to placebo). Risk of dystonia (and probably other EPS) may be greater with increased doses, use of conventional antipsychotics, males, and younger patients. Factors associated with greater vulnerability to tardive dyskinesia include older in age, female gender combined with postmenopausal status, Parkinson disease, pseudoparkinsonism symptoms, affective disorders (particularly major depressive disorder), concurrent medical diseases such as diabetes, previous brain damage, alcoholism, poor treatment response, and use of high doses of antipsychotics (APA [Lehman 2004]; Soares-Weiser 2007). Consider therapy discontinuation with signs/symptoms of tardive dyskinesia.
• Falls: May increase the risk for falls due to somnolence, orthostatic hypotension, and motor or sensory instability. Complete fall risk assessments at baseline and periodically during treatment in patients with diseases or on medications that may also increase fall risk.
• Hyperglycemia: Atypical antipsychotics have been associated with development of hyperglycemia; in some cases, may be extreme and associated with ketoacidosis, hyperosmolar coma, or death. Use with caution in patients with diabetes or other disorders of glucose regulation; monitor for worsening of glucose control.
• Hyperprolactinemia: Use is associated with increased prolactin levels; clinical significance of hyperprolactinemia in patients with breast cancer or other prolactin-dependent tumors is unknown.
• Hypersensitivity: Hypersensitivity reactions, including anaphylaxis, angioedema, throat tightness, oropharyngeal swelling, swelling of the face, lips, mouth and tongue, rash, pruritus, and urticaria, have been reported.
• Neuroleptic malignant syndrome (NMS): Use may be associated with NMS; monitor for mental status changes, fever, muscle rigidity and/or autonomic instability; risk may be increased in patients with Parkinson disease or Lewy body dementia. (McKeith 2002)
• Orthostatic hypotension: May cause orthostatic hypotension associated with dizziness, tachycardia, and syncope; use with caution in patients with known cardiovascular disease (heart failure, history of myocardial infarction or ischemia, conduction abnormalities), cerebrovascular disease, or conditions that predispose the patient to hypotension (dehydration, hypovolemia, and treatment with antihypertensive medications).
• Priapism: Rare cases of priapism have been reported.
• Suicidal ideation: The possibility of a suicide attempt is inherent in psychotic illness; use with caution in high-risk patients during initiation of therapy. Prescribe the smallest quantity consistent with good patient care.
• Temperature regulation: Impaired core body temperature regulation may occur; caution with strenuous exercise, heat exposure, dehydration, and concomitant medication possessing anticholinergic effects.
• Weight gain: Significant weight gain has been observed with antipsychotic therapy; incidence varies with product. Monitor waist circumference and BMI.

Disease-related concerns:

• Dementia: [US Boxed Warning]: Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Most deaths appeared to be either cardiovascular (eg, heart failure, sudden death) or infectious (eg, pneumonia) in nature. Use with caution in patients with Lewy body dementia or Parkinson disease dementia due to greater risk of adverse effects, increased sensitivity to extrapyramidal effects, and association with irreversible cognitive decompensation or death (APA [Reus 2016]). Iloperidone is not approved for the treatment of dementia-related psychosis.
• Hepatic impairment: Use is not recommended in patients with severe hepatic impairment; use caution and consider dosage reduction in patients with moderate hepatic impairment.
• Seizures: Use with caution in patients at risk of seizures, including those with a history of seizures, head trauma, brain damage, alcoholism, or concurrent therapy with medications which may lower seizure threshold. Elderly patients may be at increased risk of seizures due to an increased prevalence of predisposing factors.

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• CYP2D6 poor metabolizers: Use with caution in patients known to be poor metabolizers of CYP2D6; dosage adjustment recommended.
• Elderly: Use caution in older adults due to increased sensitivity to adverse effects (eg, tardive dyskinesia and seizures).

Other warnings/precautions:

• Discontinuation of therapy: When discontinuing antipsychotic therapy, the American Psychiatric Association (APA), Canadian Psychiatric Association (CPA), and World Federation of Societies of Biological Psychiatry (WFSBP) guidelines recommend gradually tapering antipsychotics to avoid physical withdrawal symptoms, including anorexia, anxiety, diaphoresis, diarrhea, dizziness, dyskinesia, headache, myalgia, nausea, paresthesia, restlessness, tremulousness, and vomiting (APA [Lehman 2004]; CPA [Addington 2005]; Lambert 2007; WFSBP [Hasan 2012]). The risk of withdrawal symptoms is highest following abrupt discontinuation of highly anti-cholinergic or dopaminergic antipsychotics (Cerovecki 2013). Additional factors such as duration of antipsychotic exposure, the indication for use, medication half-life and risk for relapse should be considered. In schizophrenia, there is no reliable indicator to differentiate the minority who will not from the majority who will relapse with drug discontinuation. However, studies in which the medication of well-stabilized patients were discontinued indicate that 75% of patients relapse within 6 to 24 months. Indefinite maintenance antipsychotic medication is generally recommended, and especially for patients who have had multiple prior episodes or 2 episodes within 5 years (APA [Lehman 2004]).

Monitoring Parameters

Mental status; vital signs (as clinically indicated); blood pressure (baseline; repeat 3 months after antipsychotic initiation, then yearly); ECG (as clinically indicated); weight, height, BMI, waist circumference (baseline; repeat at 4, 8, and 12 weeks after initiating or changing therapy, then quarterly; consider switching to a different antipsychotic for a weight gain ≥5% of initial weight); CBC (as clinically indicated; monitor frequently during the first few months of therapy in patients with preexisting low WBC or history of drug-induced leukopenia/neutropenia); electrolytes (annually and as clinically indicated; perform baseline serum potassium and magnesium with periodic monitoring in patients at risk for significant electrolyte disturbances); liver function (annually and as clinically indicated); personal and family history of obesity, diabetes, dyslipidemia, hypertension, or cardiovascular disease (baseline; repeat annually); fasting plasma glucose level/HbA_1c (baseline; repeat 3 months after starting antipsychotic, then yearly); fasting lipid panel (baseline; repeat 3 months after initiation of antipsychotic; if LDL level is normal, repeat at 2- to 5-year intervals or more frequently if clinical indicated); changes in menstruation, libido, development of galactorrhea, erectile and ejaculatory function (at each visit for the first 12 weeks after the antipsychotic is initiated or until the dose is stable, then yearly); abnormal involuntary movements or parkinsonian signs (baseline; repeat weekly until dose stabilized for at least 2 weeks after introduction and for 2 weeks after any significant dose increase); tardive dyskinesia (every 12 months; high-risk patients every 6 months); ocular examination (yearly in patients >40 years; every 2 years in younger patients) (ADA, 2004; Lehman, 2004; Marder, 2004).

Pregnancy

Pregnancy Considerations

Antipsychotic use during the third trimester of pregnancy has a risk for abnormal muscle movements (extrapyramidal symptoms [EPS]) and/or withdrawal symptoms in newborns following delivery. Symptoms in the newborn may include agitation, feeding disorder, hypertonia, hypotonia, respiratory distress, somnolence, and tremor; these effects may be self-limiting or require hospitalization. Iloperidone may cause hyperprolactinemia, which may decrease reproductive function in both males and females.

The ACOG recommends that therapy during pregnancy be individualized; treatment with psychiatric medications during pregnancy should incorporate the clinical expertise of the mental health clinician, obstetrician, primary healthcare provider, and pediatrician. Safety data related to atypical antipsychotics during pregnancy is limited and routine use is not recommended. However, if a woman is inadvertently exposed to an atypical antipsychotic while pregnant, continuing therapy may be preferable to switching to a typical antipsychotic that the fetus has not yet been exposed to; consider risk:benefit (ACOG 2008).

Health care providers are encouraged to enroll women 18 to 45 years of age exposed to iloperidone during pregnancy in the Atypical Antipsychotics Pregnancy Registry (1-866-961-2388 or http://www.womensmentalhealth.org/pregnancyregistry).

Patient Education

What is this drug used for?

• It is used to treat schizophrenia.
• It may be given to you for other reasons. Talk with the doctor.

Frequently reported side effects of this drug

• Nausea
• Weight gain
• Dry mouth
• Fatigue
• Loss of strength and energy
• Stuffy nose
• Diarrhea

Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:

• Infection
• Neuroleptic malignant syndrome like fever, muscle cramps or stiffness, dizziness, very bad headache, confusion, change in thinking, fast heartbeat, abnormal heartbeat, or sweating a lot.
• High blood sugar like confusion, feeling sleepy, more thirst, hunger, passing urine more often, flushing, fast breathing, or breath that smells like fruit.
• Thoughts of suicide
• Fast heartbeat
• Arrhythmia
• Severe dizziness
• Passing out
• Behavioral changes
• Mood changes
• Tremors
• Difficulty moving
• Rigidity
• Unable to pass urine
• Change in amount of urine passed
• Dysphagia
• Seizures
• Shortness of breath
• Enlarged breasts
• Sexual dysfunction
• Nipple discharge
• No menstrual periods
• Erection that lasts more than 4 hours
• Tardive dyskinesia like unable to control body movements; tongue, face, mouth, or jaw sticking out; mouth puckering; and puffing cheeks.
• Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.