Henbane leaf (Hyoscyami folium)

Published May 5, 1988.
List of German Commission E Monographs (Phytotherapy)

Hyoscyamusblätter

Name of Drug

Hyoscyami folium, henbane leaf.

Composition of Drug

Henbane leaf consists of the dried leaves or the dried leaves and flowering tops of Hyoscyamus niger L. [Fam. Solanaceae], as well as their preparations in effective dosage.

The drug contains at least 0.05 percent total alkaloids, calculated as hyoscyamine. The alkaloids consist mainly of hyoscyamine and scopolamine.

Uses

Spasms of the gastrointestinal tract.

Contraindications

Tachycardiac arrhythmias, prostatic adenoma with urine retention, narrow-angle glaucoma, acute pulmonary edema, mechanical stenosis in any part of the gastrointestinal tract, megacolon.

Side Effects

Dryness of the mouth, disturbances of optic conditions, tachycardia, difficulty in urination.

Interactions with Other Drugs

Enhancement of anticholinergic action by tricyclic antidepressants, amantadine, antihistamines, phenothiazines, procainamide and quinidine.

Dosage

Unless otherwise prescribed:

Average single dosage:

0.5 g of standardized henbane powder corresponding to 0.25 - 0.35 mg total alkaloid. Maximum single dosage:

1 g of standardized henbane powder corresponding to 0.5 - 0.7 mg total alkaloid. Maximum daily dosage:

3 g of standardized henbane powder corresponding to 1.5 - 2.1 mg total alkaloid, calculated as hyoscyamine. Mode of Administration Standardized henbane powder and galenical preparations for internal application.

Actions

Henbane preparations produce a parasympatholytic or anticholinergic effect by competitive inhibition of acetylcholine. This inhibition affects the muscarinic action of acetylcholine but not its nicotine-like effects on ganglia and motor end-plates.

Henbane preparations exert peripheral actions on the autonomic nervous system and on smooth muscle, as well as the central nervous system. Because of their parasympatholytic properties, they cause relaxation of organs containing smooth muscle, particularly in the region of the gastrointestinal tract. Furthermore, they relieve muscular tremors of central nervous origin.

The spectrum of actions of Hyoscyamus niger additionally includes a sedative effect.