Antimuscarinic (quaternary)
Pregnancy: Animal reproduction and teratology studies have not been performed. Cohort data on parasympatholytics indicate a possible association with minor malformations. In view of this, Pro-Banthine should not be administered in pregnancy unless considered essential. It is unknown whether propantheline bromide is excreted in human breast milk and no animal studies have been conducted, so it should not be administered during breast-feeding unless considered essential. Suppression of lactation may occur with parasympatholytics.
Propantheline bromide
Brand names: Pro-Banthine
Propantheline bromide is an antimuscarinic (anticholinergic) agent that has been used for conditions including urinary frequency and detrusor instability, as well as gastrointestinal smooth muscle spasm and hyperhidrosis.
Adult dose
Dose: Adults (the SPC gives one regimen for all licensed uses: adjunct in GI disorders characterised by smooth muscle spasm, hyperhidrosis, adult enuresis): recommended initial starting dose is one 15 mg tablet before each meal and two 15 mg tablets at bedtime; subsequently adjust according to the patient's individual response and tolerance.
Route: Oral. Tablets should be taken at least one hour before meals (food has been reported to reduce bioavailability).
Frequency: One tablet before each meal and two tablets at bedtime (initial regimen), then adjusted to individual response and tolerance
SOURCE: UK SPC, Pro-Banthine 15mg tablets (eMC product 229). Section 4.1: indicated in adults for adjunctive treatment in GI disorders characterised by smooth muscle spasm, hyperhidrosis and adult enuresis; the SPC gives no indication-specific doses. The tablet strength is 15 mg (product name). NO MAXIMUM IS PUBLISHED: the SPC says only 'Doses up to 120mg may be required in some patients' and does not state whether that figure is per dose or per day, so it is not presented as a ceiling. Elderly: 'Elderly patients may be more susceptible to antimuscarinic side effects; glaucoma and urinary retention may occur. Consideration should be given to the presence of other disease and concomitant drug therapy.' Children: 'Safety and efficacy of Pro-Banthine in children have not been established' - no paediatric dose is given. Food: 'Food has been reported to reduce the bioavailability of Pro-Banthine. Tablets should be taken at least one hour before meals.' Excipient warnings (section 4.4): patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency, or of galactose intolerance or total lactase deficiency, should not take this medicine; less than 1 mmol sodium (23 mg) per 15 mg tablet.
Dose adjustments
Renal
No renal dose adjustment is stated in the SPC. Section 4.4: use with caution in all patients with renal disease.
Hepatic
No hepatic dose adjustment is stated in the SPC. Section 4.4: use with caution in all patients with hepatic disease.
Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.
Contraindications
- Hypersensitivity to the active substance or to any of the excipients listed in section 6.1
- Obstructive diseases of the gastrointestinal or urinary tract
- Pyloric stenosis, paralytic ileus, intestinal atony
- Severe ulcerative colitis or toxic megacolon
- Hiatus hernia associated with reflux oesophagitis
- Unstable cardiovascular adjustment in acute haemorrhage
- Myasthenia gravis
- Prostatic enlargement
- Closed-angle glaucoma, or a shallow anterior chamber, since it may raise intra-ocular pressure
Side effects
- Dryness of the mouth with difficulty in swallowing, and thirst
- Dilatation of the pupils with loss of accommodation and sensitivity to light; increased intra-ocular pressure
- Flushing, dryness of the skin, decreased sweating, heat stroke
- Bradycardia followed by tachycardia, palpitations and arrhythmias
- Urinary hesitancy and retention
- Constipation; reduced bronchial secretions
- Occasional confusion in the elderly
- Occasional nausea and vomiting; occasional dizziness
Interactions
- Antimuscarinics tend to delay gastric emptying, so they may alter the absorption of other medication given concomitantly
- Other antimuscarinic agents (belladonna alkaloids, synthetic and semi-synthetic antimuscarinics, other drugs with antimuscarinic activity): excessive muscarinic blockade may occur
- Increased risk of antimuscarinic side effects with nefopam, disopyramide, MAOIs, tricyclic or tricyclic-related antidepressants, antihistamines and clozapine
- Reduced absorption of ketoconazole, and possibly of levodopa; absorption of paracetamol reported to be reduced and retarded; absorption of nitrofurantoin reported to be enhanced
- Slow-dissolving digoxin tablets: concurrent use may cause increased serum digoxin levels
- Antimuscarinics antagonise the effects of domperidone and metoclopramide on gastrointestinal activity, and the effects of parasympathomimetics
- Sublingual nitrate tablets: effect possibly reduced (failure to dissolve under the tongue owing to dry mouth)
- Haloperidol: effects possibly reduced; phenothiazines: plasma concentration reduced but risk of antimuscarinic side effects increased; amantadine: increased risk of antimuscarinic side effects; memantine: effects of antimuscarinics possibly enhanced
Monitoring
- Observe patients with severe heart disease closely, in whom an increase in heart rate is undesirable
- Use with caution in the elderly and in all patients with autonomic neuropathy, hepatic or renal disease, hyperthyroidism, coronary heart disease, congestive heart failure, cardiac arrhythmias or hypertension
- Also use with caution in Down's syndrome, gastrointestinal reflux disease, acute myocardial infarction, cardiac insufficiency and pyrexia
- Patients with ulcerative colitis: intestinal motility may be suppressed to the point of paralytic ileus, precipitating or aggravating toxic megacolon
- Ileostomy or colostomy: diarrhoea may be a symptom of incomplete intestinal obstruction and therapy should be avoided in such patients
- Fever and heat stroke may be induced in a high environmental temperature because of decreased sweating
Clinical monograph
How it works
It is a quaternary ammonium antimuscarinic that competitively blocks acetylcholine at muscarinic receptors, reducing smooth muscle tone and secretions.
Prescribing in practice
- It is contraindicated in angle-closure glaucoma, significant bladder outflow or gastrointestinal obstruction and myasthenia gravis.
- Use with caution in older people, who are more susceptible to antimuscarinic adverse effects including confusion, constipation and urinary retention.
- It is best taken before food, as administration with food reduces its absorption.
Monitoring
Monitor for anticholinergic adverse effects and for symptom control, with particular attention to cognition and bowel and bladder function in older patients.
Counselling the patient
- Take the medicine before meals as directed.
- Expect a dry mouth and report difficulty passing urine, constipation or blurred vision.
Evidence & guidelines
It is a long-established antimuscarinic; consult the SPC and current prescribing references for licensed uses and cautions.
Reference: Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).
Related
Curated clinical cross-links plus same-class fallbacks.