Hyoscyamine

Also indexed as: Anaspaz®, Colidrops Liquid Pediatric®, Cystospaz®, Donnamar®, ED-Spaz®, Hyco Elixir®, Hyosol®, Hyospaz®, Hyosyne®, Levbid®, Levsin®, Levsinex®, Losamine®, Medispaz®, Spacol®, Spasdel®, Symax®

Hyoscyamine is used in the treatment of peptic ulcers and of Parkinson’s disease to reduce stiffness, tremors, and excess sweating. It acts as a drying agent in the treatment of hay fever and is also used to treat spasm and increased movement of both the intestines in irritable bowel syndrome and the bladder in urinary tract infections. Hyoscyamine is a belladonna alkaloid in a class of drugs known as anticholinergic antispasmodics.

Safetychecker Summary for Hyoscyamine
(for details about the summarized interactions, read the full article)

Beneficial May be Beneficial: Depletion or interference—The medication may deplete or interfere with the absorption or function of the nutrient. Taking these nutrients may help replenish them.

Iron
Avoid Avoid: Adverse interaction—Avoid these supplements when taking this medication because taking them together may cause undesirable or dangerous results.

Anisodus tanguticus*
Side effect reduction/prevention

None known
Supportive interaction

None known
Reduced drug absorption/bioavailability

None known

An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.

Interactions with Dietary Supplements

Iron
Absorption of ferrous citrate, an iron compound that is usually well absorbed, is reduced in individuals taking hyoscyamine;1 therefore, these two substances should not be taken at the same time.

Interactions with Herbs

Anisodus tanguticus
The herb Anisodus tanguticus contains a chemical that has effects similar to atropine, a compound related to hyoscyamine.2 Though no human studies have investigated a possible adverse interaction between hyoscyamine and anisodus, individuals should avoid the combination until more is known.

Interactions with Foods and Other Compounds

Alcohol
Drinking alcohol interferes with the stomach acid–blocking action of atropine,3 a drug similar to hyoscyamine. Alcohol may reduce the effectiveness of hyoscyamine for this reason, and should therefore be avoided by people taking hyoscyamine.

References:

1. Orrego-Matte H, Fernandez O, Mena I. Effect of anticholinergic agents on the intestinal absorption of 59 Fe ferrous citrate. Am J Dig Dis 1971;16:789–95.

2. Qicheng F. Some current study and research approaches relating to the use of plants in the traditional Chinese medicine. J Ethnopharmacol 1980;2:57–63.

3. Kolbel CB, Singer MV, Mohle T, et al. Action of intravenous ethanol and atropine on the secretion of gastric acid, pancreatic enzymes and bile acids and the motility of the upper gastrointestinal tract in nonalcoholic humans. Pancreas 1986;1:211–8.