Pimozide toxicity

The answer is b. (Katzung, p 4822) Haloperidol, a butyrophenone, is by far the most likely antipsychotic to produce extrapyramidal toxicides Other agents, such as piperazine (an aromatic phenothiazine), thiothixene (a thioxanthene), and pimozide (a diphenylbutyropiperidine) are comparitively less likely to produce extrapyramidal toxicity than haloperi-dol. The antagonism of dopamine in the nigrostriatal system might explain the Parkinson-like effects Both haloperidol and pimozide act mainly on D2 receptors, whereas thioridazine and piperazine act on ooadrenergie receptors, and have a less potent but definite effect on D2 receptors. 

Flockhart DA, Richard E, Woosley RL, et al. A metabolic interaction between clarithromycin and pimozide may result in cardiac toxicity. Clin Pharmacol Ther 1996 59 189-189. 

LOOP DIURETICS ANTIPSYCHOTICS- ATYPICALS, PHENOTHIAZINES, PIMOZIDE Risk of arrhythmias Cardiac toxicity directly related to hypokalaemia Monitor potassium levels every 4-6 weeks until stable, then at least annually... 

Several newer drugs of varied beterocyclic structure are also effeetive in schizophrenia, ineluding elozapine, loxapine, olanzapine, molindone, pimozide, risperidone, quetiapine, and sertindole. In some cases, these atypical antipsychotic drugs have proved to be more effective and less toxic than the older drugs. However, they are much more eostly than standard drugs, most of whieh are preseribed generically. 

Pimozide (22) resembles haloperidol in its profile in experimental animals but is longer acting and relatively less toxic ... 

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