Emetics agents

The answer is d. (Hardman, p 414.) Antipsychotic agents, particularly prochlorperazine, are also useful as anti emetic agents, thought to be due to dopamine blockade at the stomach and at the chemoreceptor trigger zone of the medulla. 

Ondansetron is a 5HT3 antagonist indicated as an anti-emetic agent in nausea and vomiting associated with chemotherapy. The dose administered depends on the emetogenic degree of the chemotherapeutic agents used. 

The narcotic antagonists are naltrexone and naloxone (Narcan). Dextromethorphan (Romilar) is used as an antitussive preparation. Apomorphine is used as an emetic agent. 

Due to their potent antiemetic action, metoclopramide and domperidone are used for the prevention and treatment of emesis (see Anti emetic Agents). 

Some of the earliest and most complete efforts at structural dissection have been carried through by Cannon and his co-workers at the University of Iowa. These studies were initially directed toward elucidation of the pharmacophoric element within the structure of the emetic agent apomorphine, I. The suggestion by Pinder et al. (2) that the 5,6-dihydroxy-2-aminotetralin fragment was the active moiety was followed in short order by the report of Cannon et al. (3) that the N,N-dimethyl derivative ("M-7") II was a potent emetic in the dog. Additional pharmacology on M-7 provided by Long et al. (4) further illustrated the similarity between I and II. Both... 

Apomorphine is a dopamine agonist with a variegated pattern of usage. Given parenter-ally as an emetic agent to aid elimination of orally ingested poisons, it is not without hazards (hypotension, respiratory depression). In akinetic motor disturbances, it is a back-up drug. Taken orally, it supposedly is beneficial in erectile dysfunction. 

Diphenylaminechlorarsine (DM) Diphenylaminechlorarsine (DM) (see Figure 12.9) or Adamsite are pro-emetic agents used in WWI. DM has greater toxicity than other RCAs and has been abandoned in favor of compounds with less toxicity and greater safety ratios. While toxicity is typically delayed with DM exposure, toxic signs and symptoms can occur within minutes after exposure. Systemic toxicity may also be more pronounced and prolonged. Symptoms often subside hours after exposure. Because DM is an antiquated RCA, this compound is irrelevant today and will not be discussed further. 

PARP-1 inhibitor with the specificity and in vivo activity to enhance chemotherapy and radiation therapy of human cancer (Calabrese et al, 2004). GR205171 has the most potent anti-emetic activity of any tachykinin NKl receptor antagonist described to date. The compound is orally active in the ferret and dog, long-lasting, and warrants further investigation as a potential broad-spectrum anti-emetic agent (Gardner et al, 1996). 

Penta JS, Poster DS, Bruno S, et al (1981) Clinical trials with anti-emetic agents in cancer patients receiving chemotherapy. J Clin Pharmacol 21 11S-22S... 

AG acts as a natural AA precursor whose metabolism by COX and generation of PGEj (an emetic agent) participates in positive modulation of inflammatory mediators such as NO production and COX-2 induction, which may induce certain types of vomiting (Chang et al., 2001 Jeon et al., 1996). 

Lilly chemists prepared 998b as part of a series of 4-amino-6-heteroaryl-l,3,4,5-tetrahydrobenz[c,d]indoles evaluated as anti-emetic agents via coupling of 2-(tributylstannyl)oxazole 996 with (+)- 2aR, 45)-l-benzoyl-6-iodo-4-(di-n-pro-pylamino)-l,2,2a,3,4,5-hexahydrobenz[c,d]indole 997. They isolated 998b after deprotection as shown in Scheme 1.266. 

Ipecac symp is an alkaloid derivative of the ipecacuanha plant (Cephaline ipecacuanha). The principal alkaloids, emetine and cephaeline, both have emeto-genic properties. The emetine extract has been used for the treatment of amebiasis. Syrup of ipecac is widely available over the counter as an effective, rapidly acting emetic agent. Presently, the major source of poisoning is chronic intoxication resulting from intentional misuse by patients with eating disorders. Cases of Munchausen s syndrome by proxy, in which a parent repeatedly administers ipecac to a child, have also been reported. 

Brodie RR et al. (1986). Pharmacokinetics and bioavailability of the anti-emetic agent Bromopride. Biopharm DrugDisp 7 215-222. 

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