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Interactions between Humigen DM and Pimozide

1 drug interaction and 35 additional warnings found for the following 2 drugs:

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Drug interactions

Moderate drug interactions

Moderate:

dextromethorphan pimozide

Applies to: Humigen DM (dextromethorphan / guaifenesin) and pimozide
Monitor

Central nervous system- and/or respiratory-depressant effects may be additively or synergistically increased in patients taking multiple drugs that cause these effects, especially in elderly or debilitated patients. Sedation and impairment of attention, judgment, thinking, and psychomotor skills may increase.

Management

During concomitant use of these drugs, patients should be monitored for potentially excessive or prolonged CNS and respiratory depression. Cautious dosage titration may be required, particularly at treatment initiation. Ambulatory patients should be counseled to avoid hazardous activities requiring mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

References (36)
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  2. Stambaugh JE, Lane C (1983) "Analgesic efficacy and pharmacokinetic evaluation of meperidine and hydroxyzine, alone and in combination." Cancer Invest, 1, p. 111-7
  3. Sotaniemi EA, Anttila M, Rautio A, et al. (1981) "Propranolol and sotalol metabolism after a drinking party." Clin Pharmacol Ther, 29, p. 705-10
  4. Grabowski BS, Cady WJ, Young WW, Emery JF (1980) "Effects of acute alcohol administration on propranolol absorption." Int J Clin Pharmacol Ther Toxicol, 18, p. 317-9
  5. Lemberger L, Rowe H, Bosomworth JC, Tenbarge JB, Bergstrom RF (1988) "The effect of fluoxetine on the pharmacokinetics and psychomotor responses of diazepam." Clin Pharmacol Ther, 43, p. 412-9
  6. MacLeod SM, Giles HG, Patzalek G, Thiessen JJ, Sellers EM (1977) "Diazepam actions and plasma concentrations following ethanol ingestion." Eur J Clin Pharmacol, 11, p. 345-9
  7. Divoll M, Greenblatt DJ, Lacasse Y, Shader RI (1981) "Benzodiazepine overdosage: plasma concentrations and clinical outcome." Psychopharmacology (Berl), 73, p. 381-3
  8. Naylor GJ, McHarg A (1977) "Profound hypothermia on combined lithium carbonate and diazepam treatment." Br Med J, 2, p. 22
  9. Stovner J, Endresen R (1965) "Intravenous anaesthesia with diazepam." Acta Anaesthesiol Scand, 24, p. 223-7
  10. Driessen JJ, Vree TB, Booij LH, van der Pol FM, Crul JF (1984) "Effect of some benzodiazepines on peripheral neuromuscular function in the rat in-vitro hemidiaphragm preparation." J Pharm Pharmacol, 36, p. 244-7
  11. Feldman SA, Crawley BE (1970) "Interaction of diazepam with the muscle-relaxant drugs." Br Med J, 1, p. 336-8
  12. Ochs HR, Greenblatt DJ, Verburg-Ochs B (1984) "Propranolol interactions with diazepam, lorazepam and alprazolam." Clin Pharmacol Ther, 36, p. 451-5
  13. Desager JP, Hulhoven R, Harvengt C, Hermann P, Guillet P, Thiercelin JF (1988) "Possible interactions between zolpidem, a new sleep inducer and chlorpromazine, a phenothiazine neuroleptic." Psychopharmacology (Berl), 96, p. 63-6
  14. Tverskoy M, Fleyshman G, Ezry J, Bradley EL, Jr Kissin I (1989) "Midazolam-morphine sedative interaction in patients." Anesth Analg, 68, p. 282-5
  15. "Product Information. Iopidine (apraclonidine ophthalmic)." Alcon Laboratories Inc
  16. Greiff JMC, Rowbotham D (1994) "Pharmacokinetic drug interactions with gastrointestinal motility modifying agents." Clin Pharmacokinet, 27, p. 447-61
  17. Greb WH, Buscher G, Dierdorf HD, Koster FE, Wolf D, Mellows G (1989) "The effect of liver enzyme inhibition by cimetidine and enzyme induction by phenobarbitone on the pharmacokinetics of paroxetine." Acta Psychiatr Scand, 80 Suppl, p. 95-8
  18. Markowitz JS, Wells BG, Carson WH (1995) "Interactions between antipsychotic and antihypertensive drugs." Ann Pharmacother, 29, p. 603-9
  19. (2001) "Product Information. Ultram (tramadol)." McNeil Pharmaceutical
  20. (2001) "Product Information. Artane (trihexyphenidyl)." Lederle Laboratories
  21. (2001) "Product Information. Ultiva (remifentanil)." Mylan Institutional (formally Bioniche Pharma USA Inc)
  22. (2001) "Product Information. Seroquel (quetiapine)." Astra-Zeneca Pharmaceuticals
  23. (2001) "Product Information. Meridia (sibutramine)." Knoll Pharmaceutical Company
  24. (2001) "Product Information. Tasmar (tolcapone)." Valeant Pharmaceuticals
  25. Miller LG (1998) "Herbal medicinals: selected clinical considerations focusing on known or potential drug-herb interactions." Arch Intern Med, 158, p. 2200-11
  26. (2001) "Product Information. Precedex (dexmedetomidine)." Abbott Pharmaceutical
  27. (2001) "Product Information. Trileptal (oxcarbazepine)." Novartis Pharmaceuticals
  28. Ferslew KE, Hagardorn AN, McCormick WF (1990) "A fatal interaction of methocarbamol and ethanol in an accidental poisoning." J Forensic Sci, 35, p. 477-82
  29. Plushner SL (2000) "Valerian: valeriana officinalis." Am J Health Syst Pharm, 57, p. 328-35
  30. (2002) "Product Information. Xatral (alfuzosin)." Sanofi-Synthelabo Canada Inc
  31. (2002) "Product Information. Lexapro (escitalopram)." Forest Pharmaceuticals
  32. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  33. Cerner Multum, Inc. "Australian Product Information."
  34. (2012) "Product Information. Fycompa (perampanel)." Eisai Inc
  35. (2014) "Product Information. Belsomra (suvorexant)." Merck & Co., Inc
  36. (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka America Pharmaceutical, Inc.

Food/lifestyle interactions

Major food/lifestyle interactions

Major:

pimozide Food/Lifestyle

Applies to: pimozide
Generally avoid

Theoretically, the coadministration with grapefruit juice may increase the plasma concentrations of pimozide. The mechanism is decreased clearance of pimozide due to inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. The use of pimozide alone has been associated with dose-dependent prolongation of the QT interval. Although clinical data are lacking, this interaction may result in potentiation of the proarrhythmic effect of pimozide and consequently an increased risk of ventricular arrhythmias such as ventricular tachycardia and torsade de pointes. In addition, alcohol may potentiate some of the pharmacologic effects of pimozide. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

Management

The manufacturer recommends avoiding grapefruit juice (and probably grapefruits) during therapy with pimozide. Patients should also be advised to avoid or limit consumption of alcohol.

References (2)
  1. "Product Information. Orap (pimozide)." Gate Pharmaceuticals
  2. Dresser GK, Spence JD, Bailey DG (2000) "Pharmacokinetic-pharmacodynamic consequences and clinical relevance of cytochrome P450 3A4 inhibition." Clin Pharmacokinet, 38, p. 41-57

Moderate food/lifestyle interactions

Moderate:

dextromethorphan Food/Lifestyle

Applies to: Humigen DM (dextromethorphan / guaifenesin)
Generally avoid

Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

Management

Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

References (4)
  1. Warrington SJ, Ankier SI, Turner P (1986) "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology, 15, p. 31-7
  2. Gilman AG, eds., Nies AS, Rall TW, Taylor P (1990) "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc.
  3. (2012) "Product Information. Fycompa (perampanel)." Eisai Inc
  4. (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka America Pharmaceutical, Inc.

Disease interactions

33 potential interactions Applies to: 27 conditions, including Seizures, Diarrhea, Arrhythmia, Breast Cancer, and Hypokalemia.

Abnormal Electrocardiogram

Major:

pimozide

Pimozide has a major potential interaction with Abnormal Electrocardiogram.

The use of pimozide is contraindicated in patients with congenital or acquired QT interval prolongation syndromes or a history of cardiac arrhythmias. Pimozide can prolong the QT interval of the electrocardiogram. The risk of torsade de pointes is progressively increased as the degree of prolongation becomes greater. Electrolyte disturbances such as hypokalemia and hypomagnesemia may augment the prolongation effect of pimozide on the QT interval and should be corrected prior to institution of pimozide therapy. In addition, patients who experience frequent, severe, or prolonged diarrhea may be subject to electrolyte losses and should be followed closely and managed accordingly during therapy with pimozide. Because sudden deaths have been reported in patients using pimozide, and electrocardiogram should be performed before starting treatment and periodically thereafter, especially during periods of dose adjustment.

Acute Alcohol Intoxication

Major:

pimozide

Pimozide has a major potential interaction with Acute Alcohol Intoxication.

The use of most miscellaneous antipsychotics is contraindicated in patients with severe central nervous system depression or comatose states from any cause (e.g., lesion, disease, drug or alcohol induced).

Alcoholism

Major:

pimozide

Pimozide has a major potential interaction with Alcoholism.

The use of neuroleptic agents is contraindicated in patients with acute alcohol intoxication exhibiting depressed vital signs. The central nervous system depressant effects of neuroleptic agents may be additive with those of alcohol. Severe respiratory depression and respiratory arrest may occur. Therapy with neuroleptic agents should be administered cautiously in patients who might be prone to acute alcohol intake.

Major:

pimozide

Pimozide has a major potential interaction with Alcoholism.

Antipsychotics can lower the seizure threshold and trigger seizures in a dose-dependent manner. Seizures have been reported in patients receiving antipsychotic therapy and may occur in epileptic patients even with maintenance of routine anticonvulsant treatment. Therapy with antipsychotics should be administered cautiously in patients with a history of seizures or other predisposing factors, such as head trauma, CNS abnormalities, and alcoholism. High dosages should be avoided if possible.

Moderate:

pimozide

Pimozide has a moderate potential interaction with Alcoholism.

Antipsychotic and neuroleptic drugs can lower the seizure threshold and trigger seizures in a dose-dependent manner. This risk is greatest in patients with a history of seizures or with conditions that lower the seizure threshold. Therapy with these drugs should be administered cautiously in patients with a history of seizures or other predisposing factors, such as head trauma, CNS abnormalities, and alcoholism.

Altered Consciousness

Major:

pimozide

Pimozide has a major potential interaction with Altered Consciousness.

The use of neuroleptic agents is contraindicated in comatose patients and patients with severe central nervous system depression. Neuroleptic agents may potentiate the CNS and respiratory depression in these patients.

Major:

pimozide

Pimozide has a major potential interaction with Altered Consciousness.

The use of most miscellaneous antipsychotics is contraindicated in patients with severe central nervous system depression or comatose states from any cause (e.g., lesion, disease, drug or alcohol induced).

Arrhythmia

Major:

pimozide

Pimozide has a major potential interaction with Arrhythmia.

The use of pimozide is contraindicated in patients with congenital or acquired QT interval prolongation syndromes or a history of cardiac arrhythmias. Pimozide can prolong the QT interval of the electrocardiogram. The risk of torsade de pointes is progressively increased as the degree of prolongation becomes greater. Electrolyte disturbances such as hypokalemia and hypomagnesemia may augment the prolongation effect of pimozide on the QT interval and should be corrected prior to institution of pimozide therapy. In addition, patients who experience frequent, severe, or prolonged diarrhea may be subject to electrolyte losses and should be followed closely and managed accordingly during therapy with pimozide. Because sudden deaths have been reported in patients using pimozide, and electrocardiogram should be performed before starting treatment and periodically thereafter, especially during periods of dose adjustment.

Breast Cancer

Moderate:

pimozide

Pimozide has a moderate potential interaction with Breast Cancer.

The chronic use of neuroleptic agents can cause persistent elevations in prolactin levels due to antagonism of dopamine D2 receptors. Based on in vitro data, approximately one-third of human breast cancers are thought to be prolactin-dependent. The clinical significance of this observation with respect to long-term neuroleptic therapy is unknown. Chronic administration of neuroleptic drugs has been associated with mammary tumorigenesis in rodent studies but not in human clinical or epidemiologic studies. Until further data are available, therapy with neuroleptic agents should be administered cautiously in patients with a previously detected breast cancer. Caution is also advised in patients with preexisting hyperprolactinemia. Hyperprolactinemia may suppress hypothalamic gonadotrophin releasing hormone (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 in patients receiving prolactin-elevating compounds; however, the clinical significance of elevated serum prolactin levels is unknown for most patients. Long-standing hyperprolactinemia when associated with hypogonadism may lead to decreased bone density in both female and male patients.

Moderate:

pimozide

Pimozide has a moderate potential interaction with Breast Cancer.

Antipsychotic drugs can elevate serum prolactin concentrations, and this elevation persists during chronic administration. This should be considered if therapy will be prescribed in patients with previously detected breast cancer as one-third of human breast cancers are prolactin-dependent in vitro. Associated disturbances such as galactorrhea, amenorrhea, gynecomastia, and impotence have been reported. Appropriate laboratory testing and follow-up is advised.

Central Nervous System Disorders

Major:

pimozide

Pimozide has a major potential interaction with Central Nervous System Disorders.

Antipsychotics can lower the seizure threshold and trigger seizures in a dose-dependent manner. Seizures have been reported in patients receiving antipsychotic therapy and may occur in epileptic patients even with maintenance of routine anticonvulsant treatment. Therapy with antipsychotics should be administered cautiously in patients with a history of seizures or other predisposing factors, such as head trauma, CNS abnormalities, and alcoholism. High dosages should be avoided if possible.

Dementia

Major:

pimozide

Pimozide has a major potential interaction with Dementia.

Antipsychotic drugs are not approved for the treatment of patients with dementia-related psychosis. Older patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death; although the causes were varied, most of the deaths appeared to be either cardiovascular (e.g., heart failure, sudden death) or infectious (e.g., pneumonia) in nature. A causal relationship with antipsychotic use has not been established. In controlled trials in older patients with dementia-related psychosis, patients randomized to risperidone, aripiprazole, and olanzapine had higher incidence of cerebrovascular adverse events (e.g., stroke, transient ischemic attack), including fatalities, compared to patients treated with placebo.

Diarrhea

Major:

pimozide

Pimozide has a major potential interaction with Diarrhea.

The use of pimozide is contraindicated in patients with congenital or acquired QT interval prolongation syndromes or a history of cardiac arrhythmias. Pimozide can prolong the QT interval of the electrocardiogram. The risk of torsade de pointes is progressively increased as the degree of prolongation becomes greater. Electrolyte disturbances such as hypokalemia and hypomagnesemia may augment the prolongation effect of pimozide on the QT interval and should be corrected prior to institution of pimozide therapy. In addition, patients who experience frequent, severe, or prolonged diarrhea may be subject to electrolyte losses and should be followed closely and managed accordingly during therapy with pimozide. Because sudden deaths have been reported in patients using pimozide, and electrocardiogram should be performed before starting treatment and periodically thereafter, especially during periods of dose adjustment.

Electrolyte Abnormalities

Major:

pimozide

Pimozide has a major potential interaction with Electrolyte Abnormalities.

The use of pimozide is contraindicated in patients with congenital or acquired QT interval prolongation syndromes or a history of cardiac arrhythmias. Pimozide can prolong the QT interval of the electrocardiogram. The risk of torsade de pointes is progressively increased as the degree of prolongation becomes greater. Electrolyte disturbances such as hypokalemia and hypomagnesemia may augment the prolongation effect of pimozide on the QT interval and should be corrected prior to institution of pimozide therapy. In addition, patients who experience frequent, severe, or prolonged diarrhea may be subject to electrolyte losses and should be followed closely and managed accordingly during therapy with pimozide. Because sudden deaths have been reported in patients using pimozide, and electrocardiogram should be performed before starting treatment and periodically thereafter, especially during periods of dose adjustment.

Gastrointestinal Obstruction

Moderate:

pimozide

Pimozide has a moderate potential interaction with Gastrointestinal Obstruction.

Most neuroleptic agents have anticholinergic activity, to which elderly patients are particularly sensitive. Clozapine and low- potency agents such as chlorpromazine and thioridazine tend to exhibit the greatest degree of anticholinergic effects in the class, while haloperidol as well as the newer, atypical agents like quetiapine, risperidone and ziprasidone have generally been associated with very low frequencies of anticholinergic adverse effects. Therapy with neuroleptic agents should be administered cautiously in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders.

Glaucoma/Intraocular Hypertension

Moderate:

pimozide

Pimozide has a moderate potential interaction with Glaucoma/Intraocular Hypertension.

Most neuroleptic agents have anticholinergic activity, to which elderly patients are particularly sensitive. Clozapine and low- potency agents such as chlorpromazine and thioridazine tend to exhibit the greatest degree of anticholinergic effects in the class, while haloperidol as well as the newer, atypical agents like quetiapine, risperidone and ziprasidone have generally been associated with very low frequencies of anticholinergic adverse effects. Therapy with neuroleptic agents should be administered cautiously in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders.

Head Injury

Moderate:

pimozide

Pimozide has a moderate potential interaction with Head Injury.

Antipsychotic and neuroleptic drugs can lower the seizure threshold and trigger seizures in a dose-dependent manner. This risk is greatest in patients with a history of seizures or with conditions that lower the seizure threshold. Therapy with these drugs should be administered cautiously in patients with a history of seizures or other predisposing factors, such as head trauma, CNS abnormalities, and alcoholism.

Hyperprolactinemia

Moderate:

pimozide

Pimozide has a moderate potential interaction with Hyperprolactinemia.

The chronic use of neuroleptic agents can cause persistent elevations in prolactin levels due to antagonism of dopamine D2 receptors. Based on in vitro data, approximately one-third of human breast cancers are thought to be prolactin-dependent. The clinical significance of this observation with respect to long-term neuroleptic therapy is unknown. Chronic administration of neuroleptic drugs has been associated with mammary tumorigenesis in rodent studies but not in human clinical or epidemiologic studies. Until further data are available, therapy with neuroleptic agents should be administered cautiously in patients with a previously detected breast cancer. Caution is also advised in patients with preexisting hyperprolactinemia. Hyperprolactinemia may suppress hypothalamic gonadotrophin releasing hormone (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 in patients receiving prolactin-elevating compounds; however, the clinical significance of elevated serum prolactin levels is unknown for most patients. Long-standing hyperprolactinemia when associated with hypogonadism may lead to decreased bone density in both female and male patients.

Moderate:

pimozide

Pimozide has a moderate potential interaction with Hyperprolactinemia.

Antipsychotic drugs can elevate serum prolactin concentrations, and this elevation persists during chronic administration. This should be considered if therapy will be prescribed in patients with previously detected breast cancer as one-third of human breast cancers are prolactin-dependent in vitro. Associated disturbances such as galactorrhea, amenorrhea, gynecomastia, and impotence have been reported. Appropriate laboratory testing and follow-up is advised.

Hypokalemia

Major:

pimozide

Pimozide has a major potential interaction with Hypokalemia.

The use of pimozide is contraindicated in patients with congenital or acquired QT interval prolongation syndromes or a history of cardiac arrhythmias. Pimozide can prolong the QT interval of the electrocardiogram. The risk of torsade de pointes is progressively increased as the degree of prolongation becomes greater. Electrolyte disturbances such as hypokalemia and hypomagnesemia may augment the prolongation effect of pimozide on the QT interval and should be corrected prior to institution of pimozide therapy. In addition, patients who experience frequent, severe, or prolonged diarrhea may be subject to electrolyte losses and should be followed closely and managed accordingly during therapy with pimozide. Because sudden deaths have been reported in patients using pimozide, and electrocardiogram should be performed before starting treatment and periodically thereafter, especially during periods of dose adjustment.

Liver Disease

Moderate:

pimozide

Pimozide has a moderate potential interaction with Liver Disease.

Pimozide is extensively metabolized by the liver, and both parent drug and metabolites are eliminated by the kidney. Patients with impaired renal and/or hepatic function may be at greater risk for adverse effects due to drug and metabolite accumulation. Therapy with pimozide should be administered cautiously in such patients.

Magnesium Imbalance

Major:

pimozide

Pimozide has a major potential interaction with Magnesium Imbalance.

The use of pimozide is contraindicated in patients with congenital or acquired QT interval prolongation syndromes or a history of cardiac arrhythmias. Pimozide can prolong the QT interval of the electrocardiogram. The risk of torsade de pointes is progressively increased as the degree of prolongation becomes greater. Electrolyte disturbances such as hypokalemia and hypomagnesemia may augment the prolongation effect of pimozide on the QT interval and should be corrected prior to institution of pimozide therapy. In addition, patients who experience frequent, severe, or prolonged diarrhea may be subject to electrolyte losses and should be followed closely and managed accordingly during therapy with pimozide. Because sudden deaths have been reported in patients using pimozide, and electrocardiogram should be performed before starting treatment and periodically thereafter, especially during periods of dose adjustment.

Neuroleptic Malignant Syndrome

Major:

pimozide

Pimozide has a major potential interaction with Neuroleptic Malignant Syndrome.

The central dopaminergic blocking effects of neuroleptic agents may precipitate or aggravate a potentially fatal symptom complex known as neuroleptic malignant syndrome (NMS). NMS is observed most frequently when high-potency agents like haloperidol are administered intramuscularly, but may occur with any neuroleptic agent given for any length of time. Clinical manifestations of NMS include hyperpyrexia, muscle rigidity, altered mental status and autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis and cardiac arrhythmias). Additional signs may include elevated creatine phosphokinase, myoglobinuria, and acute renal failure. Neuroleptic agents should not be given to patients with active NMS and should be immediately discontinued if currently being administered in such patients. In patients with a history of NMS, introduction or reintroduction of neuroleptic agents should be carefully considered, since NMS may recur.

Major:

pimozide

Pimozide has a major potential interaction with Neuroleptic Malignant Syndrome.

Neuroleptic Malignant Syndrome (NMS), a potentially fatal symptom complex, has been reported in association with the use of antipsychotic drugs. The diagnostic evaluation is complicated and the management requires immediate discontinuation of the antipsychotic therapy and intensive symptomatic treatment and medical monitoring. If a patient that has recovered from NMS requires antipsychotic drug treatment again, the reintroduction of therapy should be carefully considered as NMS recurrences have been reported.

Neutropenia

Moderate:

pimozide

Pimozide has a moderate potential interaction with Neutropenia.

The use of antipsychotics has been associated with events of leukopenia, neutropenia and agranulocytosis. Possible risk factors include preexisting low white blood cell count, and history of drug induced leukopenia/neutropenia. Patients with these risk factors should have complete blood count monitored frequently during the first few months of therapy. Patients should also be monitored for any signs or symptoms of infection. Treatment should be discontinued in any patient who develops a sore throat, fever, stomatitis, or other signs of infection along with a low WBC count or severe neutropenia (ANC < 1000/mm3).

Parkinsonism

Moderate:

pimozide

Pimozide has a moderate potential interaction with Parkinsonism.

The use of neuroleptic agents is associated with pseudo-parkinsonian symptoms such as akinesia, bradykinesia, tremors, pill-rolling motion, cogwheel rigidity, and postural abnormalities including stooped posture and shuffling gait. The onset is usually 1 to 2 weeks following initiation of therapy or an increase in dosage. Older neuroleptic agents such as haloperidol are more likely to induce these effects, and their use may be contraindicated in patients with Parkinson's disease or parkinsonian symptoms.

Pituitary Tumor

Major:

pimozide

Pimozide has a major potential interaction with Pituitary Tumor.

Pimozide may have a tumorigenic potential and has been shown to cause a dose-related increase in pituitary tumors in mice. When treated for up to 18 months, pituitary gland changes that occurred were characterized as hyperplasia at doses approximating the human dose and adenoma at doses about 15 times the maximum recommended human dose on a mg/kg basis. The full significance of this finding is unknown but should be considered when prescribing pimozide, particularly in patients with preexisting pituitary tumors.

Renal Dysfunction

Moderate:

pimozide

Pimozide has a moderate potential interaction with Renal Dysfunction.

Pimozide is extensively metabolized by the liver, and both parent drug and metabolites are eliminated by the kidney. Patients with impaired renal and/or hepatic function may be at greater risk for adverse effects due to drug and metabolite accumulation. Therapy with pimozide should be administered cautiously in such patients.

Respiratory Arrest

Major:

pimozide

Pimozide has a major potential interaction with Respiratory Arrest.

The use of neuroleptic agents is contraindicated in comatose patients and patients with severe central nervous system depression. Neuroleptic agents may potentiate the CNS and respiratory depression in these patients.

Seizures

Moderate:

pimozide

Pimozide has a moderate potential interaction with Seizures.

Antipsychotic and neuroleptic drugs can lower the seizure threshold and trigger seizures in a dose-dependent manner. This risk is greatest in patients with a history of seizures or with conditions that lower the seizure threshold. Therapy with these drugs should be administered cautiously in patients with a history of seizures or other predisposing factors, such as head trauma, CNS abnormalities, and alcoholism.

Tardive Dyskinesia

Moderate:

pimozide

Pimozide has a moderate potential interaction with Tardive Dyskinesia.

Tardive dyskinesia (TD) has occurred in patients treated with antipsychotic drugs; the syndrome consists of potentially irreversible, involuntary, dyskinetic movements. The risk appears highest in older patients (particularly older women) but it is not possible to predict which patients are likely to develop TD; whether antipsychotic drugs differ in their potential to cause TD is unknown. The risk of TD and the likelihood that it will become irreversible increase with the duration of therapy and the total cumulative dose. The syndrome can develop after relatively brief treatment periods, even at low dosages; it may also occur after discontinuation of therapy. TD may remit (partially or completely) upon discontinuation of antipsychotic therapy, although antipsychotic therapy itself may suppress (or partially suppress) signs/symptoms of TD, possibly masking the underlying process; the effect of symptomatic suppression on the long-term course of TD is unknown. In patients with preexisting drug-induced TD, initiating or increasing the dosage of antipsychotic therapy may temporarily mask the symptoms of TD but could eventually worsen the condition. In patients requiring chronic therapy, the lowest dose and shortest duration of therapy producing a satisfactory clinical response are recommended; the need for continued therapy should be reassessed periodically. If signs/symptoms of TD occur during antipsychotic therapy, discontinuation of the offending agent should be considered; however, some patients may require treatment despite the presence of TD.

Tic Disorder

Major:

pimozide

Pimozide has a major potential interaction with Tic Disorder.

Pimozide is contraindicated in the treatment of simple tics or tics other than those associated with Tourette's Disorder.

Urinary Retention

Moderate:

pimozide

Pimozide has a moderate potential interaction with Urinary Retention.

Most neuroleptic agents have anticholinergic activity, to which elderly patients are particularly sensitive. Clozapine and low- potency agents such as chlorpromazine and thioridazine tend to exhibit the greatest degree of anticholinergic effects in the class, while haloperidol as well as the newer, atypical agents like quetiapine, risperidone and ziprasidone have generally been associated with very low frequencies of anticholinergic adverse effects. Therapy with neuroleptic agents should be administered cautiously in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders.

More resources

Humigen DM

A total of 375 drugs are known to interact with Humigen DM.

pimozide

A total of 776 drugs are known to interact with pimozide.

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

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