An antispasmodic (synonym: spasmolytic) is a pharmaceutical drug or other agent that suppresses muscle spasms.
One type of antispasmodics is used for smooth muscle relaxation, especially in tubular organs of the gastrointestinal tract. The effect is to prevent spasms of the stomach, intestine or urinary bladder. Both dicyclomine and hyoscyamine are antispasmodic due to their anticholinergic action. Both of these drugs have general side effects and can worsen gastroesophageal reflux disease.
Mebeverine is a muscolotropic spasmolytic with a strong and selective action on the smooth muscle spasm of the gastrointestinal tract, particularly of the colon. It does not have the acetylecholine side effect commonly seen in an anticholinergic antispasmodic.
Papaverine is an opium alkaloid used to treat visceral spasms, erectile dysfunction and investigated as antipsychotic drug due to its potency to inhibit phosphodiesterase PDE10A.
Peppermint oil has been traditionally used as an antispasmodic, and a review of studies on the topic found that it "could be efficacious for symptom relief in IBS" (as an antispasmodic) although more carefully controlled studies are needed. A later study showed it is an effective antispasmodic when test-applied topically to the intestine during endoscopy.