The
antiemetic effects of a novel serotonin3 receptor antagonist,
DAT-582 [(6R)-(-)-N-[1-methyl-4-(3-methylbenzyl)hexahydro-1H-1,4- diazepin-6-yl]-1H-
indazole-3-carboxamide dihydrochloride] were compared with those of the existing serotonin3 receptor antagonists,
ondansetron and
granisetron, in experimental animals. In ferrets,
DAT-582 (0.003-0.1 mg/kg i.v. twice) dose-relatedly prolonged the latency to the first
emetic episode and decreased the number of
emetic episodes induced by
cisplatin (10 mg/kg i.v.).
DAT-582 was more potent than
ondansetron or
granisetron in inhibiting the
emesis. The
emesis induced by
cyclophosphamide (150 mg/kg i.v.),
doxorubicin (15 mg/kg i.v.) or combination of
cisplatin (3.3 mg/kg i.v.),
cyclophosphamide (50 mg/kg i.v.) and
doxorubicin (5 mg/kg i.v.) was also inhibited by
DAT-582 (0.1 mg/kg i.v., twice). When administered 2 hr before
cisplatin in ferrets,
DAT-582 decreased markedly the number of
emetic episodes induced by
cisplatin at 0.1 mg/kg i.v., whereas
ondansetron and
granisetron were without effect even at 0.3 mg/kg i.v.
DAT-582 (0.1 mg/kg i.v.), when administered in the ferrets which were
vomiting after
cisplatin, immediately and almost completely blocked the subsequent
emesis. Furthermore,
DAT-582 (0.1 mg/kg i.v.) completely inhibited the
cisplatin (3 mg/kg i.v.)-induced
emesis for 24 hr after
cisplatin in three of five dogs. In addition,
DAT-582, at 0.3 and 1 mg/kg, p.o., inhibited the
cisplatin-induced
emesis in dogs. However,
DAT-582, even at 3 mg/kg s.c., did not inhibit the
apomorphine (0.3 mg/kg,, s.c.)-induced
emesis in dogs, or the
nicotine-,
copper sulfate- or motion stimulus-induced
emesis in the house
musk shrew, Suncus Murinus.(ABSTRACT TRUNCATED AT 250 WORDS)