In this double-blind, four-week study, 28 chronic schizophrenic patients receiving neuroleptic medication plus the antiparkinsonian drug, benztropine mesylate, were either switched to placebo or maintained on benztropine. Patients withdrawn from benztropine reliably increased their overall scores on the Wechsler Memory Scale in comparison with the drug group. Sub-test scores suggest that deficits in attention and concentration were induced by treatment with benztropine. Psychotic decompensation appeared to develop simultaneously with extrapyramidal symptoms (EPS) in some patients, but only 14.2 per cent of the placebo group experienced extrapyramidal symptoms severe enough to require resumption of benztropine therapy. It is suggested that antiparkinsonian agents should be prescribed only if and when EPS occur.

Central atropine-like toxicity in combined psychotropic drug administration.

The withdrawal of benztropine mesylate in chronic schizophrenic patients.

Aspects of the pharmacology of the phenothiazine antipsychotic agents pertinent to possible interactions are reviewed. Pharmacokinetic interactions of possible clinical importance are the interference with the absorption of the phenothiazines by antacids, reversal of the hypotensive effect of guanethidine by psychotropic drugs, blockade of the effects of levodopa in Parkinson's disease, and stimulation of phenothiazine-metabolizing enzymes by phenobarbital. Pharmacologically, phenothiazines may potentiate certain depressant effects of other CNS depressants or add to the anticholinergic side effects of a number of other drugs. The phenothiazines appear to antagonize both the CNS stimulant and the anorexic effects of amphetamines and related substances. Other reactions of possible concern are the phenothiazine-induced hypoglycemia, the relationship of lithium toxicity to sodium intake, and the number of false positive pregnancy tests in patients on phenothiazine therapy.

Central atropine-like toxicity in combined psychotropic drug administration.

Citations

The withdrawal of benztropine mesylate in chronic schizophrenic patients.

Interactions of CNS Drugs: Psychotherapeutic Agents—The Antipsychotic Drugs

Related Papers (5)

Adverse reaction to atropine and the treatment of organophosphate intoxication.

Efficacy and toxicity of drug combinations in treatment of physostigmine toxicosis.

Pharmacokinetic implications for the clinical use of atropine, scopolamine and glycopyrrolate

Pharmacokinetics and related pharmacodynamics of anticholinergic drugs.

Atropine for premedication: is no longer the time to be nostalgic.