PT  - JOURNAL ARTICLE
AU  - CARY EGGLESTON
TI  - THE ANTAGONISM BETWEEN ATROPIN AND CERTAIN CENTRAL EMETICS
DP  - 1916 Oct 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 11--25
VI  - 9
IP  - 1
4099  - http://jpet.aspetjournals.org/content/9/1/11.short
4100  - http://jpet.aspetjournals.org/content/9/1/11.full
SO  - J Pharmacol Exp Ther1916 Oct 01; 9
AB  - 1. Experiments on dogs have shown that pilocarpin, nicotin, morphin, apomorphin, emetin, aconitin and ouabain produce vomiting through direct stimulation of some portion of the central vomiting mechanism. 2. In dogs small doses of atropin, given shortly before or together with pilocarpin or nicotin, prevent the emetic action of both of these drugs, but not that of the other drugs mentioned. 3. Doses of atropin similar to those which antagonize the emetic action of nicotin and that of the smaller doses of pilocarpin are too small to cause demonstrable effects in dogs when given alone. 4. The doses of atropin effective against the emetic action of pilocarpin, in whatever dose used, fail to antagonize such other actions of pilocarpin as stimulation of the salivary and bronchial glands, of intestinal peristalsis, and of the bladder to contraction. 5. The ratio of the antagonistic dose of atropin to the dose of pilocarpin was determined for the minimal emetic dose of the latter and for each of several multiples thereof. 6. The effectiveness of the antagonistic action of atropin toward pilocarpin increases progressively as the doses of both drugs are raised so that while the ratio of atropin to pilocarpin is 1:75 for the minimal emetic dose of the latter it is 1:125 for eight times the minimal dose. Or, when the minimal dose of pilocarpin is raised eight times the dose of atropin has to be increased only about five times to antagonize its emetic action. 7. Hyoscyamin is nearly eight times as active as atropin in antagonizing the emetic action of pilocarpin.