Prevention of physostigmine-induced lethality in rats. A pharmacological analysis.

A systematic study of a large number of compounds from various pharmacological classes was performed to better define their interaction with the cholinergic nervous system. An 'in vivo' test procedure called 'physostigmine antagonism' in rats was used; it involved the administration of the test compounds, measurement of the pupil diameter and recording of the survival time after injection of a lethal dose of physostigmine. Known peripherally acting anticholinergics, such as isopropamide and methylscopolamine did not protect from physostigmine lethality at doses up to more than 150 times the mydriatic dose.

Delay of castor oil diarrhoea in rats: a new way to evaluate inhibitors of prostaglandin biosynthesis.

Forty-four non-steroidal anti-inflammatory compounds were tested for possible effects on castor oil-induced diarrhoea in rats. A small but significant delay of intestinal evacuations was found with all compounds. Quantitatively, the oral doses required to delay diarrhoea beyond the first hour after castor oil challenge reflected the acute anti-inflammatory potency of the tested compounds.

Oxatomide, a new orally active drug which inhibits both the release and the effects of allergic mediators.

Oxatomide is a new potent inhibitor of anaphylactic and allergic reactions. After oral administration, the compound both inhibits the release of endogenous histamine and prevents the effects of exogensous histamine, at comparable doses. The combination of these effects appears to be the basis of the effectiveness of oxatomide in allergic reactions and may lead to clinical application different from classical antihistaminics and from cromoglycate.