Antipsychotics antiemetic activity

Chlorprothixene has an antipsychotic and sedative action. It has expressed antiemetic activity. It is used in various psychoses, schizophrenia, reactive and neurotic depression with prevalent anxious symptomatology, and in conditions of excitement associated with fear and stress. It may be used in small doses as a sedative agent in neurosis. Synonyms of chlorprothixene are clothixene and tarasan. 

In our 1987 review, we summarized the research and clinical experience in this area [1], Surprisingly, in spite of the enormous public interest in medical marijuana and countless articles in the daily press and magazines focused predominantly on this aspect of marijuana use, little progress has been reported on the antiemetic activity of cannabinoids in the last decade. Plasse et al. have reviewed the clinical experience gained over 7 years with dronabinol (d9-THC) in antiemetic treatment [117]. With doses of 7 mg/m2 or below, complete response was noted in 36% of the patients, 32% showed partial response and 32% showed no response. However, 65% displayed drowsiness and dizziness and 12% had dysphoric effects. Combination treatment of dronabinol with prochlorperazine (a dopamine receptor blocker widely used as an antipsychotic drug with antiemetic effects) was more effective than each drug alone [118]. 

Phenothiazines are antipsychotic agents that can be used for their potent antiemetic and sedative properties (see Chapter 29). The antiemetic properties of phenothiazines are mediated through inhibition of dopamine and muscarinic receptors. Sedative properties are due to their antihistamine activity. The agents most commonly used as antiemetics are prochlorperazine, promethazine, and thiethylperazine. 

As a broad generalization it can be stated that the alkylaminopropyl group (compounds 1-3, Table 12-11) possess useful antipsychotic properties, marked sedation, and relatively modest antihistaminic and anticholinergic activities. Promazine is the least potent of the trio. The CF3 group of triflupromazine imparts the highest potency here all three are effective antiemetics. None is antinauseant in cases of motion sickness, however. Hypotension is encountered, as is a high tendency toward extrapyramidal effects. 

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