dicyclomine

Dicyclomine is a prescription drug that is used for treating irritable bowel syndrome (IBS). Dicyclomine is in a class of drugs called anticholinergics.

Anticholinergic drugs block the effects of acetylcholine, the chemical transmitter that nerves release in order to cause muscles to contract. They prevent contraction of muscles by blocking the acetylcholine receptors on the muscle cells. Anticholinergic drugs also have a direct relaxing effect on muscle. Dicyclomine is used to reduce contraction of the muscles in the intestines.

Dicyclomine was approved by the FDA in 1950.

Common side effects include:

• dry mouth (xerostomia),
• blurred vision,
• confusion,
• agitation,
• increased heart rate,
• heart palpitations,
• constipation,
• difficulty urinating, and
• seizures.

Other important side effects include:

• changes in taste perception,
• difficulty swallowing,
• headache, nervousness,
• drowsiness,
• weakness,
• dizziness,
• impotence,
• flushing,
• delirium,
• difficulty falling asleep,
• nausea,
• vomiting,
• rash,
• erythema,
• fainting,
• bloating, and
• difficulty breathing.

• The recommended starting oral dose of dicyclomine is 20 mg given 4 times daily. The dose can be increased to 40 mg 4 times daily.
• The recommended intramuscular injection is 10 to 20 mg 4 times daily.
• The intramuscular injection is only used for 1 to 2 days if a patient cannot take capsules or tablets.

Antiglaucoma Agents

Anticholinergics antagonize the effects of antiglaucoma agents and may increase intraoccular pressure. Anticholinergic drugs in the presence of increased intraocular pressure may be hazardous when taken concurrently with agents such as corticosteroids. Use of Bentyl in patients with glaucoma is not recommended.

Other Drugs with Anticholinergic Activity

The following agents may increase certain actions or side effects of anticholinergic drugs including Bentyl:

• amantadine,
• antiarrhythmic agents of Class I (for example, quinidine),
• antihistamines,
• antipsychotic agents (for example, phenothiazines),
• benzodiazepines,
• MAO inhibitors,
• narcotic analgesics (for example, meperidine),
• nitrates and nitrites,
• sympathomimetic agents,
• tricyclic antidepressants, and
• other drugs having anticholinergic activity.

Other Gastrointestinal Motility Drugs

Interaction with other gastrointestinal motility drugs may antagonize the effects of drugs that alter gastrointestinal motility, such as metoclopramide.

Effect of Antacids

Because antacids may interfere with the absorption of anticholinergic agents including Bentyl, simultaneous use of these drugs should be avoided.

Effect on Absorption of Other Drugs

Anticholinergic agents may affect gastrointestinal absorption of various drugs by affecting on gastrointestinal motility, such as slowly dissolving dosage forms of digoxin; increased serum digoxin concentration may result.

Effect on Gastric Acid Secretion

The inhibiting effects of anticholinergic drugs on gastric hydrochloric acid secretion are antagonized by agents used to treat achlorhydria and those used to test gastric secretion.

There are no adequate studies of the effect of dicyclomine in pregnant women at recommended doses (80-160 mg/day). Observation of women who received dicyclomine (up to 40 mg/day) containing products during the first trimester of pregnancy did not reveal any increased risk of harm to the fetus.

Dicyclomine is excreted into breast milk. Since there have been reports of apnea (cessation of breathing) when dicyclomine has been given to children, it should not be used by nursing mothers.

What preparations of dicyclomine are available?

• Capsules: 10 mg. Tablets: 20 mg. Syrup: 10 mg/5 mL. Injection (Intramuscular): 10 mg/ mL

How should I keep dicyclomine stored?

• Capsules, tablets, and injection should be stored at room temperature, between 15 C to 30 C (59 F to 86 F). Injection should be protected from freezing.