- An alkaloid found in hyoscyamus, belladonna, duboisine, and stramonium; the levorotatory component of the racemic mixture, atropine; used as an antispasmodic, analgesic, and sedative; h. hydrobromide is used for the same purposes. SYN: daturine.- h. sulfate an antispasmodic, hypnotic, and sedative, also used in parkinsonism to relieve tremor, rigidity, and excessive salivation.
* * *hyo·scy·a·mine .hī-ə-'sī-ə-mēn n a poisonous crystalline alkaloid C17H23NO3 of which atropine is a racemic mixture esp its levorotatory form found esp. in the plants belladonna and henbane and used similarly to atropine
* * *hyo·scy·amine (hi″o-siґə-mēn) [USP] an anticholinergic and antimuscarinic alkaloid derived from Hyoscyamus niger, Atropa belladonna, and other solanaceous plants. It is the levorotatory component of racemic atropine; since the dextrorotatory component has little activity, hyoscyamine has approximately twice the potency of atropine. It is used primarily as an antispasmodic for gastrointestinal or urinary tract disorders; administered orally.
Medical dictionary. 2011.