Source and Composition. The concrete juice of Lactuca virosa, the acid lettuce, (nat. ord. Compositae). It contains Lactucin, a bitter principle; Lactucerin, a neutral substance; Lactucic Acid, and other unimportant substances. It is partly soluble in alcohol and ether, and when triturated with water it yields a turbid mixture. Dose, gr. v-xxx.
- Tinctura Lactucarii,—50 p. c. Dose ♏x-ℨij.
- Syrupus Lactucarii,—has 10 p. c. of the tinct. Dose, ℨj-℥j.
Physiological Action. Lactucarium is feebly hypnotic, sedative and diuretic. It is supposed to act similarly to Opium, but much more feebly, and without depressing after-symptoms.
Therapeutics. It is used as a substitute for Opium, and as a remedy for cough. The syrup is best employed as a vehicle for more active agents of the same class.
A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.