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ALIMENTARY TRACT AND METABOLISM › DRUGS FOR FUNCTIONAL GASTROINTESTINAL DISORDERS › DRUGS FOR FUNCTIONAL GASTROINTESTINAL DISORDERS › Synthetic anticholinergics, quaternary ammonium compounds
methantheline
A03AB07
Adult Dosing
- Peptic ulcer or gastrointestinal hypermotility: 50 mg orally every 6 hours
- Maximum daily dose: 300 mg
Pediatric Dosing
- Safety and efficacy in pediatric patients not established
Indications
- Adjunctive therapy in the treatment of peptic ulcer disease
- Management of gastrointestinal hypermotility and hypersecretion
Mechanism of Action
- Synthetic quaternary ammonium anticholinergic agent
- Competitively blocks acetylcholine at muscarinic receptors in the gastrointestinal tract and smooth muscle
- Reduces gastric acid secretion, GI motility, and smooth muscle spasm
Contraindications
- Hypersensitivity to methantheline or other anticholinergics
- Narrow-angle glaucoma
- Obstructive uropathy (e.g., prostatic hypertrophy)
- Obstructive disease of the gastrointestinal tract (e.g., pyloroduodenal stenosis)
- Paralytic ileus or intestinal atony
- Severe ulcerative colitis or toxic megacolon
- Myasthenia gravis
Adverse Reactions
- Xerostomia (dry mouth)
- Blurred vision and cycloplegia
- Constipation
- Urinary retention
- Tachycardia and palpitations
- Drowsiness and dizziness
- Decreased sweating and anhidrosis
Drug Interactions
- Amantadine: May increase anticholinergic side effects
- Antihistamines with anticholinergic properties: Potentiation of drying and sedative effects
- Phenothiazines and tricyclic antidepressants: Enhanced anticholinergic adverse effects
- Digoxin: Quaternary anticholinergics may increase serum digoxin concentration via decreased GI motility
Curated Content: Needs Vetting Before Put to Clinical Use