Henbane Interactions Overview

Additional Details

Is Henbane Safe? Are There Any Warnings?

• Henbane leaf is considered possibly safe when used orally and appropriately in the short-term.
• Standardized henbane leaf powder has been used with apparent safety in single doses of up to 1 gram, containing 500-700 mg of total alkaloids.
• The maximum daily dosage should not exceed 3 grams, corresponding to 1500-2100 mg of total alkaloids.
• However, henbane leaf is likely unsafe when used orally in doses above 3 grams daily, as excessive doses can lead to poisoning and death due to its narrow therapeutic range.
• Henbane seed and flower safety information is insufficient, so caution is advised.
• During pregnancy and lactation, henbane is likely unsafe when used orally due to the risk of poisoning.

What Are the Possible Adverse Effects of Henbane?

• When used orally, henbane can cause anticholinergic effects, including dry mouth, vision disturbances, tachycardia, difficult urination, constipation, and skin flushing.
• At higher doses, poisoning can occur due to the presence of hyoscyamine and scopolamine in henbane, leading to symptoms such as hyperpyrexia, somnolence, CNS stimulation, hallucinations, delirium, memory impairment, ataxia, manic episodes, exhaustion, and coma.
• Henbane can cause death by asphyxiation.

Effectiveness and Uses of Henbane

• Henbane is used orally for various conditions, including toothache, peptic ulcers, muscle cramps, abdominal pain, and gastrointestinal spasms.
• Topically, it is used for scarring.
• However, there is insufficient reliable information available to determine its overall effectiveness for these uses.

How Is Henbane Thought To Work? What Is the Mechanism of Action?

• The applicable parts of henbane are the dried leaves, flowering tops, and dried seeds.
• The primary constituents responsible for its activity are the tropane alkaloids, including hyoscyamine, hyoscine, and scopolamine.
• These tropane alkaloids competitively inhibit acetylcholine, causing anticholinergic and parasympatholytic effects, particularly in the GI tract, leading to smooth muscle relaxation.
• Henbane also has CNS effects, including sedation.
• Traditionally, henbane is used for the treatment of Parkinson's disease, likely due to its anticholinergic effects and inhibition of monoamine oxidase B (MAO-B) activity, reducing dopamine breakdown.

Pharmacokinetics

• There is insufficient reliable information available about the pharmacokinetics of henbane.

Interactions with Drugs and Supplements

• Henbane may have additive anticholinergic effects and adverse effects when taken with drugs or supplements that also have anticholinergic properties.
• Such drugs and supplements include amantadine, antihistamines, atropine, belladonna alkaloids, hyoscyamine, phenothiazines, procainamide, scopolamine, tricyclic antidepressants, and other anticholinergic herbs.
• Caution should be exercised to avoid potential interactions and adverse effects.

Drugs that interact with Henbane