Ephedra. Ephedra vulgaris Rich. (Fam. Gnetaceae.)—Nagai has extracted from this Japanese plant an alkaloid, ephedrine, which, according to Kinnossuke, produces in the lower animals acceleration of the pulse, with lowering of the blood pressure, elevation of the rectal temperature, dilatation of the pupils, convulsions, and death by arrest of the heart and respiration. (B. K. W., 1887.) Scriba found that a 10 per cent. solution dilates the pupil with certainty, in from forty to sixty minutes, without irritation, the dilatation not being complete, and the accommodation not at all or only slightly affected, and the pupils returning to normal in from five to twenty hours. An alkaloid has also been discovered in Ephedra distachya L., a shrub whose branches and root are used in Siberia as a remedy in gout and syphilis. According to Robert, this alkaloid is essentially different from, ephedrine, in not being mydriatic or poisonous. P. Spehr (A. J. P., 1892, 234) considers that E. vulgaris contains two alkaloids, ephedrine and pseudo-ephedrine, isomeric and of the formula C10H15ON, while E. monostachya contains a crystalline base melting at 112° C. (233.6° F.) and having the formula C13H19ON. This latter, as stated by Kobert, is not mydriatic or poisonous. See paper by E. Schmidt, A. Pharm., cd, 1912, Nos. 2 and 3, 154, 161. According to Gunsberg, pseudo-ephedrine is a powerful mydriatic, its 10 per cent. solution causing in fifteen minutes dilatation of the eye through excitement of the sympathetic nerve.
Ephedra nevadensis S. Wats and E. antisyphilitica C. A. Meyer , which grow abundantly in the extreme Western United States, are used under the names of caynote, canutilo, whorehouse tea, as a remedy in gonorrhea. Loew thinks that their virtues reside in a peculiar tannin. Dose, of fluid-extract, from one to two fluidrachms (3.75-7.5 mils). In Texas E. trifurca Torr. is similarly employed.