Detailed Drug Information:

DRUG CLASS AND MECHANISM: Dicyclomine is an anticholinergicdrug, a medication that reduces the effect of acetylcholine, a chemicalreleased from nerves that stimulates muscles, by blocking the receptorsfor acetylcholine on smooth muscle (a type of muscle). It also has adirect relaxing effect on smooth muscle. It is used to treat or preventspasm in the muscles of the gastrointestinal tract in the irritable bowelsyndrome. Dicyclomine was approved by the FDA in 1950.

PREPARATIONS: Capsules: 10mg. Tablets: 20mg.

STORAGE: Capsules and tablets should be stored at roomtemperature, between 15° (59°F) and 30°C (86°F).

PRESCRIBED FOR: Dicyclomine is used in the treatment ofirritable bowel syndrome.

DOSING: Dicyclomine may be taken with or without food. It isusually given 3 or 4 times daily.

DRUG INTERACTIONS: Additive anticholinergic effects may be seenwith some antihistamines [carbinoxamine (Rondec), clemastine (Tavist),diphenhydramine (Benadryl), promethazine (Phenergan)], some phenothiazines[e.g. thioridazine (Mellaril), triflupromazine (Stelazine)], sometricyclic antidepressants [e.g. amitriptyline (Elavil), amoxapine(Asendin), clomipramine (Anafranil), protriptyline (Vivactil)], clozapine (Clozaril), cyclobenzaprine (Flexeril), and disopyramide (Norpace). Theadded effects of these drugs lead to a greater incidence of dry mouth,blurred vision, confusion, agitation, increased heart rate, heartpalpitations, constipation, urinary retention, and seizures than whendicyclomine is used alone. Narcotics [e.g., oxycodone (Percocet,Percodan), hydrocodone (Vicodin)] can interact with dicyclomine and resultin greater depression of the muscles of the bowel and bladder resulting ingreater constipation and difficulty urinating than may been seen withdicyclomine alone.

Dicyclomine adds to the sedating effects of alcohol and other drugs thatcause sedation such as the benzodiazepine class of anti-anxiety drugs(e.g., Valium, Ativan, Klonopin, Xanax), the narcotic class of painmedications and its derivatives (e.g., Percocet, Vicodin, Dilaudid,Codeine, Darvon), the tricyclic class of antidepressants (e.g., Elavil,Tofranil, Norpramin), and certain antihypertensive medications (e.g.,Catapres, Inderal).

Dicyclomine can reverse the effects of cisapride (Propulsid) ormetoclopramide (Reglan) on gastrointestinal motility. Conversely, theselatter two drugs can reverse the effects of dicyclomine.

Antacids and absorbent anti-diarrheals (e.g., Kaopectate) can decreasethe absorption of dicyclomine. Therefore, doses of antacids or absorbentanti-diarrheals should be separated by at least 2 hours from doses ofdicyclomine.

PREGNANCY: Between 1956 and 1976, dicyclomine was one of thecomponents of Benedictine, a combination of medications used to treatpregnancy-associated nausea. Benedictine was reformulated in 1976, anddicyclomine was removed when it was shown that it did not contribute tothe nausea suppressing effect of Benedectin. Dicyclomine appears to be safeduring pregnancy in both animal studies and in extensive human use.

NURSING MOTHERS: Dicyclomine is excreted into breast milk. Sincethere have been reports of apnea (cessation of breathing) when dicyclominehas been given to children, it should probably not be used by nursingmothers.

SIDE EFFECTS: The most common side effects occurring withdicyclomine are due to its anticholinergic activity: dry mouth, blurredvision, confusion, agitation, increased heart rate, heart palpitations,constipation, difficulty urinating, and occasionally seizures can occur.Other potential side effects include changes in taste perception,difficulty swallowing, headache, nervousness, drowsiness, weakness,dizziness, impotence, flushing, difficulty falling asleep, nausea, vomiting, rash, and a bloated feeling.