ILOPERIDONE Drug Interactions: What You Need to Know

INTERACTIONS The dose of Iloperidone Tablets should be reduced in patients co-administered a strong CYP2D6 or CYP3A4 inhibitor. ( 2.2 , 7.1 )

7.1 Clinically Important Drug Interactions with Iloperidone Table 7 presents clinically important drug interactions with Iloperidone.

Table

7: Clinically Important Drug Interactions with Iloperidone Strong CYP2D6 Inhibitors Clinical Impact Coadministration of fluoxetine with iloperidone increased exposure (area under curve, [AUC]) of iloperidone and its metabolite P88, by about 2- to 3- fold, and decreased the AUC of its metabolite P95 by one-half [see Clinical Pharmacology ( 12.3 , 12.5 )]. Coadministration of paroxetine with iloperidone resulted in increased mean steady- state peak concentrations of iloperidone and its metabolite P88, by about 1.6- fold, and decreased mean steady-state peak concentrations of its metabolite P95 by one-half [see Clinical Pharmacology ( 12.3 , 12.5 )].

Intervention

Reduce the dose of iloperidone by one-half when administered with strong CYP2D6 inhibitors. When a strong CYP2D6 inhibitor is withdrawn from the combination therapy, the iloperidone dose should be returned to the previous level [see Dosage and Administration ( 2.4 )]. Strong CYP3A4 Inhibitors Clinical Impact Co-administration of ketoconazole with iloperidone, increased the AUC of iloperidone and its metabolites P88 and P95 by 57%, 55%, and 35%, respectively [see Clinical Pharmacology ( 12.3 )].

Intervention

Reduce the dose of iloperidone by one-half when administered with strong CYP3A4 inhibitors. When the CYP3A4 inhibitor is withdrawn from the combination therapy, the iloperidone dose should be returned to the previous level [see Dosage and Administration ( 2.4 )]. Concomitant use of Strong CYP2D6 and Strong CYP3A4 Inhibitors Clinical Impact Coadministration of iloperidone with paroxetine and ketoconazole resulted in a 1.4- fold increase in steady-state concentrations of iloperidone and its metabolite P88 and a 1.4- fold decrease in the P95 in the presence of paroxetine [see Clinical Pharmacology ( 12.3 )].

Intervention

Coadministration of iloperidone with inhibitors of both CYP2D6 and CYP3A4 did not add to the effect of either inhibitor given alone. Reduce the dose of iloperidone by about one-half if administered concomitantly with both a CYP2D6 and CYP3A4 inhibitor same as if it is coadministered with only one inhibitor. When the inhibitors of CYP2D6 and CYP3A4 are withdrawn from the combination therapy, the iloperidone dose should be returned to the previous level [see Dosage and Administration ( 2.4 )].

7.2 Drugs that Prolong the QT Interval Concomitant use of drugs that prolong the QT interval may add to the QT effects of Iloperidone and increase the risk of cardiac arrhythmia. Avoid the use of Iloperidone in combination with any other drugs that prolong the QT interval <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.3 )]</span>.

7.3 Drugs that Lower Blood Pressure Concomitant use of Iloperidone with medications that lower blood pressure could potentially cause symptomatic hypotension. Avoid coadministration of Iloperidone with alpha-adrenergic blocking agents and adjust medications that affect blood pressure as needed <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.7 )]</span>.

Iloperidone is contraindicated in individuals with a known hypersensitivity reaction to the product. Anaphylaxis, angioedema, and other hypersensitivity reactions have been reported [see Adverse Reactions (6.2) ]. Known hypersensitivity to Iloperidone or to any components in the formulation. ( 4 , 6.2 )

AND PRECAUTIONS Cerebrovascular Adverse Reactions in Elderly Patients with Dementia- Related Psychosis: Increased incidence of cerebrovascular adverse reactions (e.g., stroke, transient ischemic attack). ( 5.2 ) QT prolongation: Prolongs QT interval and may be associated with arrhythmia and sudden death. Avoid use of FANAPT in combination with other drugs that are known to prolong QTc; use caution and consider dose modification when prescribing FANAPT with other drugs that inhibit FANAPT metabolism. Monitor serum potassium and magnesium in patients at risk for electrolyte disturbances. ( 1 , 5.3 , 7.1 , 7.2 , 12.3 )

Neuroleptic Malignant

Syndrome (NMS): Manage with immediate discontinuation of drug and close monitoring. ( 5.4 ) Tardive dyskinesia: Discontinue if clinically appropriate. ( 5.5 )

Metabolic

Changes: Monitor for hyperglycemia/diabetes mellitus, dyslipidemia and weight gain. ( 5.6 ) Orthostatic hypotension and Syncope: Monitor heart rate and blood pressure and warn patients with known cardiovascular or cerebrovascular disease, and risk of dehydration or syncope. ( 5.7 ) Seizures: Use cautiously in patients with a history of seizures or with conditions that lower seizure threshold. ( 5.9 ) Leukopenia, Neutropenia, and Agranulocytosis have been reported with antipsychotics. Perform complete blood counts (CBC) in patients with pre-existing low white blood cell count (WBC) or a history of leukopenia/neutropenia. Consider discontinuing FANAPT if clinically significant decline in WBC occurs in the absence of other causative factors. ( 5.10 ) Priapism: Cases have been reported in association with FANAPT treatment. Severe priapism may require surgical intervention. ( 5.14 ) Potential for cognitive and motor impairment: Use caution when operating machinery. ( 5.15 )

Intraoperative Floppy Iris

Syndrome (IFIS): IFIS during cataract surgery may require modifications to the surgical technique. ( 5.16 )

5.1 Increased Mortality in Elderly Patients with Dementia-Related Psychosis Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Analyses of 17 dementia-related psychosis placebo-controlled trials (modal duration of 10 weeks) largely in patients taking atypical antipsychotic drugs, revealed a risk of death in the drug-treated patients of between 1.6 to 1.7 times that in placebo-treated patients. Over the course of a typical 10-week controlled trial, the rate of death in drug-treated patients was about 4.5%, compared to a rate of about 2.6% in placebo-treated patients. Although the causes of death were varied, most of the deaths appeared to be either cardiovascular (e.g., heart failure, sudden death) or infectious (e.g., pneumonia) in nature. FANAPT is not approved for the treatment of patients with dementia-related psychosis <span class="opacity-50 text-xs">[see Boxed Warning , Warnings and Precautions (5.2) ]</span> .

5.2 Cerebrovascular Adverse Reactions, Including Stroke, in Elderly Patients with Dementia-Related Psychosis In placebo-controlled trials in elderly subjects with dementia, patients randomized to risperidone, aripiprazole, and olanzapine had a higher incidence of stroke and transient ischemic attack, including fatal stroke. FANAPT is not approved for the treatment of patients with dementia-related psychosis <span class="opacity-50 text-xs">[see Boxed Warning , Warnings and Precautions (5.1) ]</span> .

5.3 QT Prolongation In an open-label QTc study in patients with schizophrenia or schizoaffective disorder (n=160), FANAPT was associated with QTc prolongation of 9 msec at an iloperidone dose of 12 mg twice daily. The effect of FANAPT on the QT interval was augmented by the presence of CYP450 2D6 or 3A4 metabolic inhibition (paroxetine 20 mg once daily and ketoconazole 200 mg twice daily, respectively). Under conditions of metabolic inhibition for both 2D6 and 3A4, FANAPT 12 mg twice daily was associated with a mean QTcF increase from baseline of about 19 msec. No cases of torsade de pointes or other severe cardiac arrhythmias were observed during the pre-marketing clinical program. The use of FANAPT should be avoided in combination with other drugs that are known to prolong QTc including Class 1A (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmic medications, antipsychotic medications (e.g., chlorpromazine, thioridazine), antibiotics (e.g., gatifloxacin, moxifloxacin), or any other class of medications known to prolong the QTc interval (e.g., pentamidine, levomethadyl acetate, methadone). FANAPT should also be avoided in patients with a known genetic susceptibility to congenital long QT syndrome and in patients with a history of cardiac arrhythmias. Certain circumstances may increase the risk of torsade de pointes and/or sudden death in association with the use of drugs that prolong the QTc interval, including (1) bradycardia; (2) hypokalemia or hypomagnesemia; (3) concomitant use of other drugs that prolong the QTc interval; and (4) presence of congenital prolongation of the QT interval; (5) recent acute myocardial infarction; and/or (6) uncompensated heart failure. Caution is warranted when prescribing FANAPT with drugs that inhibit FANAPT metabolism <span class="opacity-50 text-xs">[see Drug Interactions (7.1) ]</span> , and in patients with reduced activity of CYP2D6 <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3 , 12.5) ]</span> . It is recommended that patients being considered for FANAPT treatment who are at risk for significant electrolyte disturbances have baseline serum potassium and magnesium measurements with periodic monitoring. Hypokalemia (and/or hypomagnesemia) may increase the risk of QT prolongation and arrhythmia. FANAPT should be avoided in patients with histories of significant cardiovascular illness, e.g., QT prolongation, recent acute myocardial infarction, uncompensated heart failure, or cardiac arrhythmia. FANAPT should be discontinued in patients who are found to have persistent QTc measurements &gt;500 msec. If patients taking FANAPT experience symptoms that could indicate the occurrence of cardiac arrhythmias, e.g., dizziness, palpitations, or syncope, the prescriber should initiate further evaluation, including cardiac monitoring.

5.4 Neuroleptic Malignant Syndrome (NMS)

Neuroleptic Malignant

Syndrome (NMS), a potentially fatal symptom complex, has been reported in association with administration of antipsychotic drugs, including FANAPT. Clinical manifestations include hyperpyrexia, muscle rigidity, altered mental status (including catatonic signs), and evidence of autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac dysrhythmia). Additional signs may include elevated creatine phosphokinase, myoglobinuria (rhabdomyolysis), and acute renal failure. If NMS is suspected, immediately discontinue FANAPT and provide intensive symptomatic treatment and monitoring.

5.5 Tardive Dyskinesia Tardive dyskinesia, a syndrome consisting of potentially irreversible, involuntary, dyskinetic movements, may develop in patients treated with antipsychotic drugs. The risk appears to be highest among the elderly, especially elderly women, but it is impossible to predict, which patients will develop the syndrome. Whether antipsychotic drug products differ in their potential to cause tardive dyskinesia is unknown. The risk of developing tardive dyskinesia and the likelihood that it will become irreversible increase with the duration of treatment and cumulative dose. The syndrome can develop after relatively brief treatment periods at low doses. It may also occur after discontinuation of treatment. Tardive dyskinesia may remit, partially or completely, if antipsychotic treatment is discontinued. Antipsychotic treatment itself may suppress (or partially suppress) the signs and symptoms of the syndrome, possibly masking the underlying process. The effect that symptomatic suppression has upon the long-term course of the syndrome is unknown. Given these considerations, FANAPT should be prescribed in a manner that is most likely to reduce the risk of tardive dyskinesia. Chronic antipsychotic treatment should generally be reserved for patients: 1) who suffer from a chronic illness that is known to respond to antipsychotic drugs, and (2) for whom alternative, equally effective, but potentially less harmful treatments are not available or appropriate. In patients who do require chronic treatment, use the lowest dose and the shortest duration of treatment producing a satisfactory clinical response. Periodically reassess the need for continued treatment. If signs and symptoms of tardive dyskinesia appear in a patient on FANAPT, drug discontinuation should be considered. However, some patients may require treatment with FANAPT despite the presence of the syndrome.

5.6 Metabolic Changes Atypical antipsychotic drugs have been associated with metabolic changes that may increase cardiovascular/cerebrovascular risk. These metabolic changes include hyperglycemia, dyslipidemia, and body weight gain. While all atypical antipsychotic drugs have been shown to produce some metabolic changes, each drug in the class has its own specific risk profile. Hyperglycemia and Diabetes Mellitus Hyperglycemia, in some cases extreme and associated with ketoacidosis or hyperosmolar coma or death, has been reported in patients treated with atypical antipsychotics including FANAPT. Assess fasting plasma glucose before or soon after initiation of antipsychotic medication and monitor periodically during long-term treatment. Schizophrenia In a 4-week fixed-dose placebo-controlled study of adults with schizophrenia, the mean change from baseline in serum glucose was 6.6 mg/dL and -0.5 mg/dL for FANAPT and placebo treated patients, respectively. The proportion of patients with shifts in fasting glucose from normal (&lt;100 mg/dL) to high (≥126 mg/dL) were 10.7% and 2.5% for FANAPT and placebo treated patients, respectively. In pooled analyses from clinical studies, for adults with schizophrenia remaining on treatment with FANAPT 10-16 mg/day glucose increased, on average, from baseline by 1.8 mg/dL at 3-6 months (N=773) and by 5.4 mg/dL at 6-12 months (N=723) and at &gt;12 months (N=425) of treatment. In a smaller group of patients remaining on treatment with FANAPT 20-24 mg/day, glucose decreased by 3.6 mg/dL at 3-6 months (N=34); by 9 mg/dL at 6-12 months (N=31), and by 18 mg/dL at &gt; 12 months (N=20) of treatment.

Bipolar

Mania In a 4-week fixed dose study of adults with bipolar mania, mean changes from baseline in serum glucose and the proportion of patients with shifts in fasting glucose from Normal (<100 mg/dL) to High (≥126 mg/dL) for patients receiving FANAPT were similar to those for patients receiving placebo.

Dyslipidemia

Undesirable alterations in lipids have been observed in patients treated with atypical antipsychotics. Before or soon after initiation of antipsychotic medications, obtain a fasting lipid profile at baseline and monitor periodically during treatment. Schizophrenia In a 4-week fixed dose study of adults with schizophrenia, the mean change from baseline in fasted total cholesterol was 8.2 mg/dL and -2.2 mg/dL for FANAPT and placebo treated patients, respectively. The effects on LDL were similar to those on total cholesterol (changes of 9 mg/dL and -1.4 mg/dL for FANAPT and placebo treated patients, respectively). Mean changes from baseline in fasted triglycerides were -0.8 mg/dL and 16.5 mg/dL for FANAPT and placebo treated patients, respectively. The proportion of patients with shifts from normal to high fasted total cholesterol, LDL, and triglycerides were similar for FANAPT and placebo-treated patients. The proportion of patients with shifts in fasted HDL from normal (≥40 mg/dL) to low (<40 mg/dL) was greater for placebo patients (23.8%) compared to patients treated with FANAPT (12.1%). In pooled analysis from clinical studies, for adults with schizophrenia remaining on treatment with FANAPT, on average, both cholesterol and triglycerides decreased from baseline for adults with schizophrenia remaining on treatment at 3-6 months, 6-12 months, and >12-month time points in both 10-16 mg/day and 20-24 mg/day dose groups.

Bipolar

Mania In a 4-week fixed dose study of adults with bipolar mania, the mean changes from baseline for fasted total cholesterol, LDL, HDL, and triglycerides for FANAPT were similar to those for placebo-treated patients. The proportion of patients with shifts in fasted total cholesterol from normal (<200 mg/dL) to high (≥240 mg/dL) was greater for FANAPT treated patients (10.7%) than placebo-treated patients (7.2%). Shifts from normal to high LDL and triglycerides and from normal to low HDL occurred at rates for FANAPT similar to those for placebo treated patients.

Weight Gain

Weight gain has been observed with atypical antipsychotic use. Monitor weight at baseline and frequently thereafter.

Schizophrenia

Across all short- and long-term studies of adults with schizophrenia, the overall mean change from baseline at endpoint was 2.1 kg.

In

4 placebo-controlled, 4- or 6-week, fixed- or flexible-dose studies in adults with schizophrenia the mean change in weight (kg) was -0.1, 2, and 2.7 for placebo, FANAPT 10-16 mg/day, and FANAPT 20-24 mg/day groups, respectively. The proportion of patients with weight gain >7% increase from baseline was 4%, 12%, and 18% for placebo, FANAPT 10-16 mg/day, and FANAPT 20-24 mg/day groups, respectively.

Bipolar

Mania In a 4-week fixed dose study of adults with bipolar mania the mean change in weight (kg) was 1.6 and 4.6 kg for placebo and FANAPT 24 mg/day groups, respectively. The proportion of patients with weight gain ≥7% increase from baseline was 14% and 35%, for placebo and FANAPT 24 mg/day groups, respectively.

5.7 Orthostatic Hypotension and Syncope FANAPT can induce orthostatic hypotension associated with dizziness, tachycardia, and syncope. This reflects its alpha1-adrenergic antagonist properties. In double-blind placebo-controlled short-term studies in patients with schizophrenia, where the dose was increased slowly, as recommended above, syncope was reported in 0.4% (5/1,344) of patients treated with FANAPT, compared with 0.2% (1/587) on placebo. Orthostatic hypotension was reported in 5% of patients given 20 mg to 24 mg/day, 3% of patients given 10 mg to 16 mg/day, and 1% of patients given placebo. In a double-blind placebo-controlled short-term study in patients with bipolar mania, syncope was reported in 0.5% (1/206) of patients treated with FANAPT, compared with 0% (0/208) on placebo. In this study, orthostatic hypotension was reported in 4% (9/206) of patients treated with FANAPT and 2% (5/208) of patients given placebo. More rapid titration would be expected to increase the rate of orthostatic hypotension and syncope. Orthostatic vital signs should be monitored in patients who are vulnerable to hypotension (e.g., elderly patients, patients with dehydration, hypovolemia, and concomitant treatment with antihypertensive medications), patients with known cardiovascular disease (history of myocardial infarction, ischemic heart disease, heart failure, or conduction abnormalities), and patients with cerebrovascular disease.

5.8 Falls Antipsychotics, including FANAPT, may cause somnolence, postural hypotension, motor and sensory instability, which may lead to falls and, consequently, fractures or other injuries. For patients with diseases, conditions, or medications that could exacerbate these effects, complete fall risk assessments when initiating antipsychotic treatment and recurrently for patients on long-term antipsychotic therapy.

5.9 Seizures Like other antipsychotic drugs, FANAPT may cause seizures. The risk is greatest in patients with a history of seizures or with conditions that lower the seizure threshold. Conditions that lower the seizure threshold may be more prevalent in older patients.

5.10 Leukopenia, Neutropenia and Agranulocytosis In clinical trial and postmarketing experience, leukopenia and neutropenia have been reported temporally related to antipsychotic agents. Agranulocytosis (including fatal cases) has also been reported. Possible risk factors for leukopenia/neutropenia include preexisting low white blood cell count (WBC) and history of drug induced leukopenia/neutropenia. Patients with a pre-existing low WBC or a history of drug induced leukopenia/neutropenia should have their complete blood count (CBC) monitored frequently during the first few months of therapy and should discontinue FANAPT at the first sign of a decline in WBC in the absence of other causative factors. Monitor patients with clinically significant neutropenia for fever or other symptoms or signs of infection and treat promptly if such symptoms or signs occur. Discontinue FANAPT in patients with absolute neutrophil count &lt;1000/mm 3 and follow their WBC until recovery.

5.11 Hyperprolactinemia As with other drugs that antagonize dopamine D2 receptors, FANAPT elevates prolactin levels. Hyperprolactinemia may suppress hypothalamic GnRH, resulting in reduced pituitary gonadotropin secretion. This, in turn, may inhibit reproductive function by impairing gonadal steroidogenesis in both female and male patients. Galactorrhea, amenorrhea, gynecomastia, and impotence have been reported with prolactin-elevating compounds. Long-standing hyperprolactinemia when associated with hypogonadism may lead to decreased bone density in both female and male patients. Tissue culture experiments indicate that approximately one-third of human breast cancers are prolactin-dependent in vitro, a factor of potential importance if the prescription of these drugs is contemplated in a patient with previously detected breast cancer. Mammary gland proliferative changes and increases in serum prolactin were seen in mice and rats treated with FANAPT <span class="opacity-50 text-xs">[see Nonclinical Toxicology (13) ]</span> . Published epidemiologic studies have shown inconsistent results when exploring the potential association between hyperprolactinemia and breast cancer. In a short-term placebo-controlled trial (4-weeks) in patients with schizophrenia, the mean change from baseline to endpoint in plasma prolactin levels for the FANAPT 24 mg/day-treated group was an increase of 2.6 ng/mL compared to a decrease of 6.3 ng/mL in the placebo-group. In placebo-controlled trials in patients with schizophrenia, elevated plasma prolactin levels (≥1.15xULN) were observed in 26% of adults treated with FANAPT compared to 12% in the placebo group. In the short-term trials, FANAPT was associated with modest levels of prolactin elevation compared to greater prolactin elevations observed with some other antipsychotic agents. In pooled analysis from clinical studies including longer term trials, in 3210 adults treated with iloperidone, gynecomastia was reported in 2 male subjects (0.1%) compared to 0% in placebo-treated patients, and galactorrhea was reported in 8 female subjects (0.2%) compared to 3 female subjects (0.5%) in placebo-treated patients. In a short-term, placebo-controlled trial (4-weeks) in patients with bipolar mania, the mean change from baseline to endpoint in plasma prolactin levels for the FANAPT group was an increase of 15.66 ng/mL compared to a decrease of 0.58 ng/mL for the placebo group. In this trial, elevated plasma prolactin levels (≥1.15xULN) were observed in 35% of adults treated with FANAPT compared to 1% of the placebo group.

5.12 Body Temperature Regulation Atypical antipsychotics may disrupt the body’s ability to reduce core body temperature. Strenuous exercise, exposure to extreme heat, dehydration, and anticholinergic medications may contribute to an elevation in core body temperature; use FANAPT with caution in patients who may experience these conditions.

5.13 Dysphagia Esophageal dysmotility and aspiration have been associated with antipsychotic drug use. Aspiration pneumonia is a common cause of morbidity and mortality in elderly patients. Antipsychotic drugs, including FANAPT, should be used cautiously in patients at risk for aspiration.

5.14 Priapism Four cases of priapism were reported in the pre-marketing FANAPT program (3 in the clinical studies for schizophrenia and 1 in the clinical study for manic and mixed episodes associated with bipolar I disorder). Drugs with alpha-adrenergic blocking effects have been reported to induce priapism. FANAPT shares this pharmacologic activity. Severe priapism may require surgical intervention.

5.15 Potential for Cognitive and Motor Impairment FANAPT, like other antipsychotics, may cause somnolence and has the potential to impair judgment, thinking or motor skills. In short-term, placebo-controlled trials of schizophrenia, somnolence (including sedation) was reported in 12% (104/874) of adult patients treated with FANAPT at doses of 10 mg/day or greater versus 5.3% (31/587) treated with placebo. In a short-term, placebo-controlled trial of bipolar mania, somnolence (including sedation) was reported in 8% (16/206) of adult patients treated with FANAPT versus 3% (6/208) treated with placebo. Patients should be cautioned about operating hazardous machinery, including motor vehicles, until they are reasonably certain that therapy with FANAPT does not affect them adversely.

5.16 Intraoperative Floppy Iris Syndrome (IFIS) IFIS has been observed during cataract surgery in some patients on or previously treated with alpha-1 adrenergic blockers. This variant of small pupil syndrome is characterized by the combination of a flaccid iris that billows in response to intraoperative irrigation currents, progressive intraoperative miosis despite preoperative dilation with standard mydriatic drugs, and potential prolapse of the iris toward the phacoemulsification incisions. The patient’s surgeon should be prepared for possible modifications to their surgical technique, such as the utilization of iris hooks, iris dilator rings, or viscoelastic substances. There does not appear to be a benefit of stopping alpha1 blocker therapy prior to cataract surgery. The initiation of therapy with FANAPT in patients for whom cataract or glaucoma surgery is scheduled is not recommended.