← Search & browse all drugs
ALIMENTARY TRACT AND METABOLISM › DRUGS FOR FUNCTIONAL GASTROINTESTINAL DISORDERS › BELLADONNA AND DERIVATIVES, PLAIN › Belladonna alkaloids, semisynthetic, quaternary ammonium compounds
methylscopolamine
A03BB03
Forms & Strengths
- Oral tablet: 2.5 mg
- Oral tablet: 5 mg
Adult Dosing
- Peptic ulcer disease: 2.5 mg orally 4 times daily (before meals and at bedtime)
- Maintenance therapy: 2.5 mg to 5 mg orally twice to 4 times daily
- Maximum daily dose: 20 mg
Pediatric Dosing
- Safety and efficacy not established in pediatric patients
Indications
- Adjunctive treatment of peptic ulcer disease
- Reduction of hypermotility in gastrointestinal tract disorders
Mechanism of Action
- Anticholinergic / antimuscarinic agent
- Competitively blocks acetylcholine at muscarinic receptors on smooth muscle, secretory glands, and in the CNS
- Reduces gastric acid secretion and gastrointestinal motility due to quaternary ammonium structure (limits CNS penetration)
Contraindications
- Hypersensitivity to methylscopolamine or other anticholinergics
- Glaucoma (narrow-angle)
- Obstructive uropathy (e.g., bladder neck obstruction due to prostatic hyperplasia)
- Obstructive disease of the gastrointestinal tract (e.g., achalasia, pyloroduodenal stenosis)
- Paralytic ileus, intestinal atony, or toxic megacolon
- Severe ulcerative colitis
- Myasthenia gravis
- Unstable cardiovascular status in acute hemorrhage
Adverse Reactions
- Xerostomia (dry mouth)
- Blurred vision and cycloplegia
- Constipation
- Urinary retention
- Tachycardia and palpitations
- Drowsiness and dizziness
- Reduced sweating leading to heat intolerance
- Urticaria and other dermal manifestations
Drug Interactions
- Amantadine: enhanced anticholinergic adverse effects
- Antipsychotics (e.g., phenothiazines): increased risk of anticholinergic toxicity and reduced antipsychotic efficacy
- Antihistamines (first-generation): additive anticholinergic effects
- Tricyclic antidepressants: potentiation of anticholinergic adverse effects
- Digoxin: slowed GI motility may increase serum digoxin absorption
- Ketoconazole: concurrent antacids/anticholinergics may decrease ketoconazole absorption
Curated Content: Needs Vetting Before Put to Clinical Use