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Drug Interactions between benztropine and haloperidol

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

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Interactions between your drugs

Moderate

haloperidol benztropine

Applies to: haloperidol and benztropine

MONITOR: Centrally-acting anticholinergic agents may antagonize the therapeutic effects of neuroleptic agents. Although these drugs have been used together clinically, the possibility of increased risk of adverse effects such as central nervous system depression and tardive dyskinesia should also be considered. In addition, excessive anticholinergic effects may occur in combination use, which can result in paralytic ileus, hyperthermia, heat stroke, and the anticholinergic intoxication syndrome. Peripheral symptoms of anticholinergic intoxication commonly include mydriasis, blurred vision, flushed face, fever, dry skin and mucous membranes, tachycardia, urinary retention, and constipation. Central symptoms may include memory loss, disorientation, incoherence, hallucinations, psychosis, delirium, hyperactivity, twitching or jerking movements, stereotypy, and seizures. In hot weather, the risk of hyperthermia and heat stroke should be considered, as neuroleptic agents can interfere with temperature regulation in the hypothalamus while anticholinergic agents tend to inhibit peripheral sweating mechanisms.

MANAGEMENT: Caution is advised if anticholinergic agents are used with neuroleptic agents, particularly in the elderly and those with underlying organic brain disease, who tend to be more sensitive to the central anticholinergic effects of these drugs and in whom toxicity symptoms may be easily overlooked. Prophylactic administration of anticholinergic agents is sometimes given clinically during neuroleptic therapy for drug-induced parkinsonism or extrapyramidal symptoms but may not always be appropriate. Patients prescribed this combination should be advised to notify their physician promptly if they experience potential symptoms of anticholinergic intoxication such as abdominal pain, fever, heat intolerance, blurred vision, confusion, and hallucinations. Ambulatory patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them. A dosage reduction in one or both drugs may be necessary if excessive adverse effects develop. During hot weather, patients should avoid prolonged sun exposure and intense physical exertion and maintain adequate fluid intake.

References

  1. Stadnyk AN, Glezos JD "Drug-induced heat stroke." Can Med Assoc J 128 (1983): 957-9
  2. Zelman S, Guillan R "Heat stroke in phenothiazine-treated patients: a report of three fatalities." Am J Psychiatry 126 (1970): 1787-90
  3. Mann SC, Boger WP "Psychotropic drugs, summer heat and humidity, and hyperplexia: a danger restated." Am J Psychiatry 135 (1978): 1097-100
  4. Rockland L, Cooper T, Schwartz F, Weber D, Sullivan T "Effects of trihexyphenidyl on plasma chlorpromazine in young schizophrenics." Can J Psychiatry 35 (1990): 604-7
  5. Warnes H, Lehmann HE, Ban TA "Adynamic ileus during psychoactive medication: a report of three fatal and five severe cases." Can Med Assoc J 96 (1967): 1112-3
  6. Rivera-Calimlim L, Nasrallah H, Strauss J, Lasagna L "Clinical response and plasma levels: effect of dose, dosage schedules, and drug interactions on plasma chlorpromazine levels." Am J Psychiatry 133 (1976): 646-52
  7. Gershon S, Neubauer H, Sundland DM "Interaction between some anticholinergic agents and phenothiazines." Clin Pharmacol Ther 6 (1965): 749-56
  8. Singh MM, Kay SR "Therapeutic antagonism between anticholinergic antiparkinsonism agents and neuroleptics in schizophrenia: implications for a neuropharmacological model." Neuropsychobiology 5 (1979): 74-86
  9. Sarnquist F, Larson CP Jr "Drug-induced heat stroke." Anesthesiology 39 (1973): 348-50
  10. Johnson AL, Hollister LE, Berger PA "The anticholinergic intoxication syndrome: diagnosis and treatment." J Clin Psychiatry 42 (1981): 313-7
  11. Lee BS "Possibility of hyperpyrexia with antipsychotic and anticholinergic drugs." J Clin Psychiatry 47 (1986): 571
  12. Forester D "Fatal drug-induced heat stroke." JACEP 7 (1978): 243-4
  13. Moreau A, Jones BD, Banno V "Chronic central anticholinergic toxicity in manic depressive illness mimicking dementia." Can J Psychiatry 31 (1986): 339-41
  14. Hvizdos AJ, Bennett JA, Wells BG, Rappaport KB, Mendel SA "Anticholinergic psychosis in a patient receiving usual doses of haloperidol." Clin Pharm 2 (1983): 174-8
  15. Roth A, Akyol S, Nelson JC "Delirium associated with the combination of a neuroleptic, an SSRI, and benztropine." J Clin Psychiatry 55 (1994): 492-5
  16. "Product Information. Cogentin (benztropine)." Merck & Co., Inc PROD (2001):
  17. Kulik AV, Wilbur R "Delirium and stereotypy from anticholinergic antiparkinson drugs." Prog Neuropsychopharmacol Biol Psychiatry 6 (1982): 75-82
  18. "Product Information. Artane (trihexyphenidyl)." Lederle Laboratories PROD (2001):
  19. Byerly MJ, Christensen RC, Evans DL "Delirium associated with a combination of sertraline, haloperidol, and benztropine." Am J Psychiatry 153 (1996): 965-6
  20. Hansen LB, Elley J, Christensen TR, Larsen NE, Naestoft J, Hvidberg EF "Plasma levels of perphenazine and its major metabolites during simultaneous treatment with anticholinergic drugs." Br J Clin Pharmacol 7 (1979): 75-80
  21. Kwok JS, Chan TY "Recurrent heat-related illnesses during antipsychotic treatment." Ann Pharmacother 39 (2005): 1940-2
View all 21 references

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Drug and food interactions

Moderate

haloperidol food

Applies to: haloperidol

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

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

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Moderate

benztropine food

Applies to: benztropine

GENERALLY AVOID: Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous. In addition, the potential for abuse may be increased with the combination. The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system. No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load. However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.

MANAGEMENT: Alcohol should generally be avoided during therapy with anticholinergic agents. Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.

References

  1. Linnoila M "Drug effects on psychomotor skills related to driving: interaction of atropine, glycopyrrhonium and alcohol." Eur J Clin Pharmacol 6 (1973): 107-12

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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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