Dicycloverine was approved for medical use in the United States in 1950.[2] It is available as ageneric medication.[1] In 2023, it was the 192nd most commonly prescribed medication in the United States, with more than 2million prescriptions.[4][5]
Dicycloverine is used to treat the symptoms ofirritable bowel syndrome, specificallyhypermotility, in adults.[6][7] As of 2016, clinical guidelines recommended dicycloverine and otherantispasmodics for IBS with diarrhea as a first line treatment.[6]
This medicine should not be used for people who have an obstructive GI or urinary condition, severe ulcerative colitis, reflux, any unstable cardiac condition, glaucoma,myasthenia gravis, and anyone who is acutely bleeding.[7]
It should not be given to children or infants with colic due to the risks of convulsions, difficult breathing, irritability, and restlessness,[9] and there is little evidence to support the efficacy in such use in any case.[10]
Dicycloverine is known to impair thinking and coordination.[7]
The effect on the baby during pregnancy or breastfeeding is not well understood.[7]
Dicycloverine can cause a range ofanticholinergic side effects such as dry mouth, nausea, blurred vision, dizziness, confusion, severe constipation, stomach pain, heart palpitations, difficulty urinating, and seizures.[6]
It was first marketed in 1952 for gastrointestinal disorders, including colic in infants.[9] The INN name "dicycloverine" was recommended in 1959.[13] It was included in thecombination drug for morning sickness calledBendectin, along withdoxylamine andvitamin B6 which was launched in the US in 1956; dicycloverine was removed from the formulation in 1976 after Merrell determined that it added no value. Bendectin became the subject of many lawsuits due to allegations that it had caused birth defects similar tothalidomide, which Merrell had also marketed in the US and Canada.[14]
In the 1980s, several governments restricted its use in infants due to reports of convulsions, difficult breathing, irritability, and restlessness in infants given the drug.[9]
In 1994, the USFederal Trade Commission orderedMarion Merrell Dow, which had acquired Rugby Darby—the only generic manufacturer of dicycloverine in the US—to promise to grant licenses to its intellectual property on the drug to any company that wanted it, based onantitrust concerns. The US market for the medication at that time was around $8 million; Dow had 60% of it and Rugby had 40%. The next year,Hoechst Marion Roussel, which by that time had acquired the business, granted a license toEndo Pharmaceuticals. By 2000 several other generic competitors had started selling the medication. The case was part of the reshaping of the US pharmaceutical market that occurred in the 1990s, to favor generic entry.[15]
Rarely, there have been reports of dicycloverine abuse. Dicycloverine is an antagonist atσ1[16] and5-HT2A[17] receptor sites, though its affinities for these targets are roughly one-fifth to one-tenth as strong as its affinities forCHRM1[18] andCHRM4[19] (its clinical targets). It is also a relatively non-polar tertiary amine, able to cross theblood–brain barrier, leading todelirium at high concentrations.[6][20]
^abcdeCanadian Agency for Drugs and Technologies in Health (3 December 2015). "Dicyclomine for Gastrointestinal Conditions: A Review of the Clinical Effectiveness, Safety, and Guidelines".CADTH Rapid Response Reports.PMID26985553.
^abcdAHFS Staff (2006)."Dicyclomine hydrochloride".AHFS DI Essentials. Bethesda, MD: American Society of Health-System Pharmacists / drugs.com. Retrieved25 November 2018.
^Chien C (2003). "Cheap Drugs at What Price to Innovation: Does the Compulsory Licensing of Pharmaceuticals Hurt Innovation?".Berkeley Technology Law Journal.18 (3):853–907.JSTOR24116860.
