Antiemetics and antinauseants

In addition to their well-established antipsychotic properties, the neuroleptics have a number of clinically important properties that include their antiemetic and antinauseant actions, their antihistaminic effects and their ability to potentiate the actions of analgesics and general anaesthetics. 

ICS 205-930 Navoban ) is a tropanyl derivative, a (5-HT3) 5-hydroxytryptamine receptor antagonist. It is an antiemetic and antinauseant for chemotherapy-induced emesis, tropisetron hydrochloride tropisetron. 

Clebopride [inn. usan] (cleboprlde n-ialate [jan]) is a substituted benzamide, a (Dj) DOPAMINE RECEPTOR ANTAGONIST, and has activity as a visceral ANTISPASMODIC and antinauseant and antiemetic. 

NSC 130004 Torecan and many other names) is a phenothiazine with general properties similar to chlorpromazine. It is a sedative and ANTIEMETIC, and is used as an antinauseant and antiemetic. thiethylperazine maleate > thiethylperazine. thimerosal thiomersal. 

Dimenhydrinate is an antiemetic especially usehil as an antinauseant in motion sickness, and for syndromes associated with vertigo such as Meniere s syndrome, radiation sickness, and vestibular dysfunction. It may produce mild drowsiness. It is FDA Category B for Pregnancy, and is available as an OTC preparation as well as by prescription. 

A number of ANALGESICS can be used to offset the pain of the attack, including aspirin, codeine and paracetamol, and these are often incorporated into compound preparations together with a variety of other drugs and drug types, e.g. caffeine, buclizine, doxylamine, isometheptene, pizotifen. Sometimes drugs with antinauseant or ANTIEMETIC properties are included, e.g. cyclizine and metoclopramide. 

As an antinauseant and antiemetic, it is used as an adjunct in cancer chemotherapy. 

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. 

Phenothiazines such as prochlorperazine, thiethylperazine, and chlorpromazine see Chapter 18) are among the most commonly used antinauseants and antiemetics. Their principal mechanism of action is dopamine receptor antagonism at the CTZ. Compared to metoclopramide or ondansetron see above), these drugs do not appear to be as uniformly effective in cancer chemotherapy-induced emesis. On the other hand, they also possess antihistaminic and anticholinergic activities, which are of value in other forms of nausea, such as motion sickness. 

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