Pregnancy Risk Category B
How supplied
Tablets: 10 mg‡, 20 mg
Capsules: 10 mg, 20 mg
Syrup: 5 mg/5 ml‡, 10 mg/5 ml
Injection: 10 mg/ml
Action
Inhibits action of acetylcholine on postganglionic, parasympathetic muscarinic receptors, decreasing GI motility. Also, possesses local anesthetic properties that may be partly responsible for spasmolysis.
Indications & dosage
Irritable bowel syndrome, other functional GI disorders--
Adults: initially, 20 mg P.O. q.i.d., increased to 40 mg q.i.d., or 20 mg I.M. q.i.d.
Adverse reactions
CNS: headache; dizziness; insomnia; light-headedness; drowsiness; nervousness, confusion, excitement (in elderly patients).
CV: palpitations, tachycardia.
EENT: blurred vision, increased intraocular pressure, mydriasis, photophobia.
GI: nausea, vomiting, constipation, dry mouth, thirst, abdominal distention, heartburn, paralytic ileus.
GU: urinary hesitancy, urine retention, impotence.
Skin: urticaria, decreased sweating or possible anhidrosis, other dermal signs and symptoms, local irritation.
Other: fever, allergic reactions.
Interactions
Drug-drug. Amantadine, antihistamines, antiparkinsonians, disopyramide, glutethimide, meperidine, phenothiazines, procainamide, quinidine, tricyclic antidepressants: additive adverse effects. Avoid concomitant use.
Antacids: decreased absorption of oral anticholinergics. Separate administration times by 2 to 3 hours.
Ketoconazole: anticholinergics may interfere with ketoconazole absorption. Separate administration times by 2 to 3 hours.
Methotrimeprazine: anticholinergics may enhance risk of extrapyramidal reactions. Avoid concomitant use.
Effects on diagnostic tests
None reported.
Contraindications
Contraindicated in patients with hypersensitivity to anticholinergics and in those with obstructive uropathy, obstructive disease of the GI tract, reflux esophagitis, severe ulcerative colitis, toxic megacolon, myasthenia gravis, unstable CV status in acute hemorrhage, tachycardia secondary to cardiac insufficiency or thyrotoxicosis, or glaucoma; also contraindicated in breast-feeding patients and in children under age 6 months.
Nursing considerations
Patient teaching
*Liquid contains alcohol. **May contain tartrazine. †Canada ‡Australia §U.K. OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING