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Drug Interactions between haloperidol and Iosal II

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

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Interactions between your drugs

Moderate

haloperidol pseudoephedrine

Applies to: haloperidol and Iosal II (guaifenesin / pseudoephedrine)

Consumer information for this interaction is not currently available.

GENERALLY AVOID: Butyrophenone neuroleptics may antagonize the pharmacologic effects of amphetamine, amphetamine derivatives, and other centrally-acting sympathomimetic agents (i.e., CNS stimulants). Conversely, these agents may diminish the neuroleptic efficacy of butyrophenones. The exact mechanism of interaction is unknown but may involve opposing effects on dopaminergic activity. Several clinical studies have demonstrated the reduction or lack of effect of amphetamines on weight loss in obese psychiatric patients treated with haloperidol and other neuroleptic agents, most notably chlorpromazine. In one of these studies, dextroamphetamine also had no effect on sleep patterns. Another study found haloperidol to inhibit amphetamine-induced symptoms and may be useful in amphetamine intoxication. As for the reverse interaction, it is uncertain whether CNS stimulants actually antagonize the neuroleptic effect of butyrophenones, since CNS stimulants alone have been reported to cause or aggravate preexisting psychotic symptoms. There has also been a report of acute dystonia occurring in two normal, healthy young women given haloperidol and dexamphetamine as part of a neuropharmacological study. The authors postulated that the reaction was due to a potentiation of dopamine release.

MANAGEMENT: Amphetamine, amphetamine derivatives, and other CNS stimulants should generally not be used, particularly for weight reduction, in patients treated with a butyrophenone neuroleptic agent.

Drug and food interactions

Moderate

haloperidol food

Applies to: 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

pseudoephedrine food

Applies to: Iosal II (guaifenesin / pseudoephedrine)

Both pseudoephedrine and caffeine can increase blood pressure and heart rate, and combining them may enhance these effects. Talk to your doctor before using these medications, especially if you have a history of high blood pressure or heart disease. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Contact your doctor if your condition changes or you experience increased side effects. 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.

Moderate

haloperidol food

Applies to: 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.

Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

See also

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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.

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