Drug information of Dicyclomine


Drug group:

Dicyclomine is an anticholinergic . It is used for Treating symptoms of irritable bowel syndrome . It may also be used for other conditions as determined by your doctor.

Mechanism of effect

Anticholinergic/antispasmodic ; no effect on acid secretion, but direct smooth muscle relaxant effects; blocks the action of ACh at parasympathetic sites in smooth muscle, secretory glands, and CNS


Dicyclomine is an anticholinergic drug , a medication that reduces the effect of acetylcholine, a chemical released from nerves that stimulates muscles, by blocking the receptors for acetylcholine on smooth muscle (a type of muscle).
It also has a direct relaxing effect on smooth muscle. Dicyclomine is used to treat or prevent spasm in the muscles of the gastrointestinal tract in the irritable bowel syndrome. In addition, Dicyclomine inhibits gastrointestinal propulsive motility and decreases gastric acid secretion and controls excessive pharyngeal, tracheal and bronchial secretions.


• Absorption: Bioavailability: PO (67% of IM)
• Onset : 1-2 hr
• Duration : <4 hr
• Peak plasma time : PO (60-90 min)
• Distribution: Vd: 3.65 L/kg
• Metabolism: Metabolites: Ranitidine N-oxide, desmethylranitidine, ranitidine
• Elimination : Half-life: 1.8 hr, Excretion: Urine (80%); feces (8%)

Drug indications



Irritable Bowel Syndrome : 20 mg PO q6hr; may increase up to 40 mg q6hr; if efficacy not achieved in 2 weeks or adverse effects require dose <80 mg/day, therapy should be discontinued; safety data not available for doses > 80 mg/day for periods > 2 weeks
10-20 mg IM q6hr; not to exceed 80 mg/day IM


Dicyclomine may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.
• Do not become overheated in hot weather or while you are being active; heatstroke may occur.
• Dicyclomine may make your eyes more sensitive to sunlight. It may help to wear sunglasses.
• Use dicyclomine with caution in the ELDERLY; they may be more sensitive to its effects.
• Dicyclomine should not be used in CHILDREN younger than 6 months old; safety and effectiveness in these children have not been confirmed.
• Use Dicyclomine caution in patients with mild-moderate ulcerative colitis, renal/hepatic impairment, benign prostatic hyperplasia, heart failure, hyperthyroidism
• Psychosis in patients sensitive to anticholinergic drugs reported (eg, elderly, mentally ill individuals); signs and symptoms resolve within 12-24 hr after discontinuation.
• Incomplete intestinal obstruction: Diarrhea may be an early symptom, especially in patients with ileostomy or colostomy .
• Salmonella dysenteric patients: Due to risk of toxic megacolon .
• Effects may be potentiated when used with other sedative drugs or ethanol .
• Serious respiratory reactions, CNS symptoms, and deaths reported following administration to infants.

Points of recommendation

• Do not use IV, For IM injection only; IV injection may result in thrombosis or thrombophlebitis and injection-site reactions .
• IM use should not be longer than 1-2 days; replace IM with PO as soon as possible .
• Do not use dicyclomine if it contains particles, is cloudy or discolored, or if the vial is cracked or damaged.
• Take 30-60 minutes before a meal
• Use dicyclomine on a regular schedule around the clock, unless your doctor tells you otherwise.

Pregnancy level


Related drugs

Belladonna , Hyoscine , Hyoscyamine

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