Skip to main content

Drug Interactions between clozapine and Haldol

This report displays the potential drug interactions for the following 2 drugs:

Edit list (add/remove drugs)

Interactions between your drugs

Major

haloperidol cloZAPine

Applies to: Haldol (haloperidol) and clozapine

Talk to your doctor before using cloZAPine together with haloperidol. CloZAPine can occasionally cause serious cardiovascular side effects such as low blood pressure and cardiac or respiratory arrest, and the risk may be greater in patients that are also receiving medications like haloperidol. Cardiovascular side effects are most likely to occur when cloZAPine is first started, when it is restarted following an interruption in therapy, or when the dose is increased rapidly. The risk and/or severity of other side effects may also be increased, including dizziness, drowsiness, blurred vision, confusion, dry mouth, abdominal cramping, constipation, difficulty urinating, heat intolerance, palpitation, irregular heart rhythm, Parkinson-like symptoms, and abnormal muscle movements involving primarily the face and sometimes the limbs. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Let your doctor know if you experience increased or excessive side effects at any time during treatment with these medications, and seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or fast or pounding heartbeats. Avoid driving or operating hazardous machinery until you know how the medications affect you, and use caution when getting up from a sitting or lying position. If you miss your cloZAPine doses for two or more days, contact your doctor before you resume treatment, as you may need to restart at a lower dose. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Drug and food interactions

Moderate

haloperidol food

Applies to: Haldol (haloperidol)

Alcohol can increase the nervous system side effects of haloperidol such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with haloperidol. Do not use more than the recommended dose of haloperidol, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. Talk to your doctor or pharmacist if you have any questions or concerns.

Moderate

cloZAPine food

Applies to: clozapine

Alcohol can increase the nervous system side effects of cloZAPine such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with cloZAPine. Do not use more than the recommended dose of cloZAPine, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. Talk to your doctor or pharmacist if you have any questions or concerns.

Moderate

haloperidol food

Applies to: Haldol (haloperidol)

Consumer information for this interaction is not currently available.

MONITOR: Smoking cessation may lead to elevated plasma concentrations and enhanced pharmacologic effects of drugs that are substrates of CYP450 1A2 (and possibly CYP450 1A1) and/or certain drugs with a narrow therapeutic index (e.g., flecainide, pentazocine). One proposed mechanism is related to the loss of CYP450 1A2 and 1A1 induction by polycyclic aromatic hydrocarbons in tobacco smoke; when smoking cessation agents are initiated and smoking stops, the metabolism of certain drugs may decrease leading to increased plasma concentrations. The mechanism by which smoking cessation affects narrow therapeutic index drugs that are not known substrates of CYP450 1A2 or 1A1 is unknown. The clinical significance of this interaction is unknown as clinical data are lacking.

MANAGEMENT: Until more information is available, caution is advisable if smoking cessation agents are used concomitantly with drugs that are substrates of CYP450 1A2 or 1A1 and/or those with a narrow therapeutic range. Patients receiving smoking cessation agents may require periodic dose adjustments and closer clinical and laboratory monitoring of medications that are substrates of CYP450 1A2 or 1A1.

Moderate

cloZAPine food

Applies to: clozapine

Consumer information for this interaction is not currently available.

MONITOR: Smoking cessation may lead to elevated plasma concentrations and enhanced pharmacologic effects of drugs that are substrates of CYP450 1A2 (and possibly CYP450 1A1) and/or certain drugs with a narrow therapeutic index (e.g., flecainide, pentazocine). One proposed mechanism is related to the loss of CYP450 1A2 and 1A1 induction by polycyclic aromatic hydrocarbons in tobacco smoke; when smoking cessation agents are initiated and smoking stops, the metabolism of certain drugs may decrease leading to increased plasma concentrations. The mechanism by which smoking cessation affects narrow therapeutic index drugs that are not known substrates of CYP450 1A2 or 1A1 is unknown. The clinical significance of this interaction is unknown as clinical data are lacking.

MANAGEMENT: Until more information is available, caution is advisable if smoking cessation agents are used concomitantly with drugs that are substrates of CYP450 1A2 or 1A1 and/or those with a narrow therapeutic range. Patients receiving smoking cessation agents may require periodic dose adjustments and closer clinical and laboratory monitoring of medications that are substrates of CYP450 1A2 or 1A1.

Minor

cloZAPine food

Applies to: clozapine

Information for this minor interaction is available on the professional version.

Therapeutic duplication warnings

Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.

Duplication

Antipsychotics

Therapeutic duplication

The recommended maximum number of medicines in the 'antipsychotics' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'antipsychotics' category:

  • clozapine
  • Haldol (haloperidol)

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.


Report options

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.