Dicyclomine Hydrochloride (4 brand names, 4 dosage forms, 2 routes)
Available dosage forms: INJECTABLE, SYRUP, CAPSULE, TABLET.
Routes of administration: INJECTION, ORAL.
Brand Names
- BENTYL
- BENTYL PRESERVATIVE FREE
- DICYCLOMINE HYDROCHLORIDE
- DICYCLOMINE HYDROCHLORIDE (PRESERVATIVE FREE)
Indications and Usage
Dicyclomine hydrochloride tablets are indicated for the treatment of patients with functional bowel/irritable bowel syndrome.
Dosage and Administration
Dosage must be adjusted to individual patient needs.
Contraindications
Dicyclomine hydrochloride is contraindicated in infants less than 6 months of age [see Use in Specific Populations ( 8.4)] , nursing mothers [see Use in Specific Populations ( 8.3 )], and in patients with: unstable cardiovascular status in acute hemorrhage myasthenia gravis [see Warnings and Precautions ( 5.4)] glaucoma [see Adverse Reactions ( 6.3) and Drug Interactions ( 7.1)] obstructive uropathy [see Warnings and Precautions ( 5.8)] obstructive disease of the gastrointestinal tract [see Warnings and Precautions ( 5.5)] severe ulcerative colitis [see Warnings and Precautions ( 5.7)] reflux esophagitis
Adverse Reactions
The pattern of adverse effects seen with dicylomine is mostly related to its pharmacological actions at muscarinic receptors [see Clinical Pharmacology ( 12)] . They are a consequence of the inhibitory effect on muscarinic receptors within the autonomic nervous system. These effects are dose-related and are usually reversible when treatment is discontinued. The most serious adverse reactions reported with dicyclomine hydrochloride include cardiovascular and central nervous system symptoms [see Warnings and Precautions ( 5.2, 5.3)] .
Mechanism of Action
Dicyclomine relieves smooth muscle spasm of the gastrointestinal tract. Animal studies indicate that this action is achieved via a dual mechanism: a specific anticholinergic effect (antimuscarinic) at the acetylcholine-receptor sites with approximately 1/8 the milligram potency of atropine ( in vitro, guinea pig ileum); and a direct effect upon smooth muscle (musculotropic) as evidenced by dicyclomine’s antagonism of bradykinin- and histamine-induced spasms of the isolated guinea pig ileum. Atropine did not affect responses to these two agonists. In vivostudies in cats and dogs showed dicyclomine to be equally potent against acetylcholine (ACh)- or barium chloride (BaCl2)-induced intestinal spasm while atropine was at least 200 times more potent against effects of ACh than BaCl2. Tests for mydriatic effects in mice showed that dicyclomine was approximately 1/500 as potent as atropine; antisialagogue tests in rabbits showed dicyclomine to be 1/300 as potent as atropine.
Overdosage
In case of an overdose, patients should contact a physician, poison control center (1-800-222-1222), or emergency room. The signs and symptoms of overdosage include: headache; nausea; vomiting; blurred vision; dilated pupils; hot, dry skin; dizziness; dryness of the mouth; difficulty in swallowing; and CNS stimulation including convulsion. A curare-like action may occur (i.e., neuromuscular blockade leading to muscular weakness and possible paralysis). One reported event included a 37-year-old who reported numbness on the left side, cold fingertips, blurred vision, abdominal and flank pain, decreased appetite, dry mouth, and nervousness following ingestion of 320 mg daily (four 20 mg tablets four times daily). These events resolved after discontinuing the dicyclomine. The acute oral LD50 of the drug is 625 mg/kg in mice. The amount of drug in a single dose that is ordinarily associated with symptoms of overdosage or that is likely to be life-threatening, has not been defined. The maximum human oral dose recorded was 600 mg by mouth in a 10-month-old child and approximately 1500 mg in an adult, each of whom survived. In three of the infants who died following administration of dicyclomine hydrochloride [see Warnings and Precautions ( 5.1)] , the blood concentrations of drug were 200, 220, and 505 ng/mL. It is not known if dicyclomine hydrochloride is dialyzable. Treatment should consist of gastric lavage, emetics, and activated charcoal. Sedatives (e.g., short-acting barbiturates, benzodiazepines) may be used for management of overt signs of excitement. If indicated, an appropriate parenteral cholinergic agent may be used as an antidote.