Propantheline Bromide
Propantheline bromide
Also known as: Pro-Banthine · bromuro de propantelina · propanthelini bromidum · Bropantil · Corrigast · Ercorax Rollon · Ercoril · Ercotina · Pantheline · Probamide
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Detrusor hyperreflexia, urge incontinence | 0.2 mg/kg PO q6-8h; increase dose if necessary to the lowest dose that will control clinical signs | PO | q6-8h | — | 🌎 NA |
| Detrusor hyperreflexia, urge incontinence | 7.5-30 mg (total dose) PO once a day to q8h | PO | q24h to q8h | — | 🌎 NA |
| Detrusor hyperreflexia, urge incontinence | 7.5-15 mg (total dose) PO q12h; occasionally dosages of 30 mg q8h are required | PO | q12h | — | 🌎 NA |
| Sinus bradycardia, incomplete AV block, etc. | 0.25-0.5 mg/kg PO q8-12h | PO | q8-12h | — | 🌎 NA |
| Sinus bradycardia, incomplete AV block, etc. | 7.5-30 mg PO q8-12h | PO | q8-12h | — | 🌎 NA |
| Colitis, irritable bowel syndrome, etc. | 0.25 mg/kg PO three times a day | PO | TID | Do not use longer than 48-72 hours (48 hours for acute colitis) | 🌎 NA |
| Colitis, irritable bowel syndrome, etc. | 0.5 mg/kg two to three times daily | PO | BID-TID | — | 🌎 NA |
| As an antiemetic/antidiarrheal | 0.25 mg/kg PO q8h | PO | q8h | — | 🌎 NA |
- Sinus bradycardia, incomplete AV block, etc.: Usually well tolerated, but improvement is usually partial and often temporary.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Detrusor hyperreflexia, urge incontinence | 0.25-0.5 mg/kg PO q12-24h | PO | q12-24h | — | 🌎 NA |
| Detrusor hyperreflexia, urge incontinence | 5-7.5 mg (total dose) PO once a day to once every 3 days | PO | q24h to q72h | — | 🌎 NA |
| Detrusor hyperreflexia, urge incontinence | 5-7.5 mg (total dose) PO q8h; 7.5 mg PO q72h | PO | q8h or q72h | — | 🌎 NA |
| Sinus bradycardia, incomplete AV block, etc. | 0.8-1.6 mg/kg three times daily | PO | TID | — | 🌎 NA |
| Sinus bradycardia, incomplete AV block, etc. | 7.5 mg PO q8-12h | PO | q8-12h | — | 🌎 NA |
| Chronic colitis | 0.5 mg/kg two to three times daily | PO | BID-TID | — | 🌎 NA |
| As an antiemetic/antidiarrheal | 0.25 mg/kg PO q8h | PO | q8h | — | 🌎 NA |
- Detrusor hyperreflexia, urge incontinence: Empirical dosage. Further studies required to substantiate beneficial effect.
- Sinus bradycardia, incomplete AV block, etc.: Although generally ineffective, a trial may be attempted.
- Sinus bradycardia, incomplete AV block, etc.: Usually well tolerated, but improvement is usually partial and often temporary.
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| To reduce rectal contractions during oocyte collection | 0.04 mg/kg IV | IV | Once | — | 🌎 NA |
| To inhibit peristalsis for 2 hours during rectal surgery | 30 mg IV | IV | Once | — | 🌎 NA |
- To reduce rectal contractions during oocyte collection: Must be freshly prepared and filtered through a 0.22 micron-filter from oral tablets.
- To inhibit peristalsis for 2 hours during rectal surgery: Must be freshly prepared and filtered through a 0.22 micron-filter from oral tablets.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Propantheline bromide is a synthetic quaternary ammonium antimuscarinic (anticholinergic) agent. It is primarily utilized in veterinary medicine for its antispasmodic and antisecretory properties.
Key Clinical Uses:
- Small Animals: Management of diarrhea, hyperreflexic detrusor (urge incontinence), and anticholinergic-responsive bradycardias.
- Horses: Administered intravenously to reduce colonic peristalsis and relax the rectum, facilitating safer rectal examinations and surgical procedures.
Clinical Pearl: Because propantheline is a quaternary ammonium compound, it is permanently ionized and highly water-soluble. This structural feature prevents it from readily crossing the blood-brain barrier (BBB) or penetrating the eye. Consequently, it provides peripheral anticholinergic effects (like GI relaxation and heart rate elevation) with significantly fewer central nervous system (CNS) or ocular adverse effects compared to tertiary amines like atropine.
Mechanism of action
Propantheline acts as a competitive antagonist at muscarinic acetylcholine receptors (primarily M1, M2, and M3 subtypes) located on smooth muscle, cardiac muscle, and exocrine glands.
- Gastrointestinal Tract: Blockade of M3 receptors → decreased smooth muscle tone and peristalsis (antispasmodic effect) + reduced gastric acid secretion.
- Urinary Tract: Blockade of M3 receptors on the detrusor muscle → relaxation of the bladder wall → increased bladder capacity and reduced urge incontinence.
- Cardiovascular System: Blockade of M2 receptors on the sinoatrial (SA) node → vagolytic effect → increased heart rate.
- Exocrine Glands: Blockade of muscarinic receptors → decreased salivation and respiratory secretions.
Safety & warnings
Contraindications
- Hypersensitivity to anticholinergics
- Tachycardias secondary to thyrotoxicosis or cardiac insufficiency
- Myocardial ischemia
- Unstable cardiac status during acute hemorrhage
- Gastrointestinal obstructive disease
- Paralytic ileus
- Severe ulcerative colitis
- Obstructive uropathy
- Myasthenia gravis (unless used to reverse adverse muscarinic effects secondary to therapy)
Adverse effects
- Dry mouth (xerostomia)
- Dry eyes (keratoconjunctivitis sicca)
- Urinary hesitancy or retention
- Tachycardia
- Constipation
- Vomiting (especially in cats)
- Hypersalivation (especially in cats)
- Ileus (at high doses, potentially leading to bacterial overgrowth)
Precautions
Extreme Caution:
- GI Infections: Can decrease GI motility and prolong retention of causative agents or toxins, worsening clinical signs.
- Autonomic Neuropathy: Use with extreme caution.
Caution:
- Hepatic or renal disease
- Hyperthyroidism
- Hypertension
- Congestive Heart Failure (CHF)
- Tachyarrhythmias
- Prostatic hypertrophy
- Esophageal reflux
- Geriatric or pediatric patients
- Nursing patients (unknown if excreted in milk, but anticholinergics can reduce milk production and cause toxicity in neonates)
Drug interactions
May enhance the anticholinergic activity of propantheline.
May enhance the activity of propantheline.
Propantheline may decrease the absorption of cimetidine.
Long-term concurrent use may increase intraocular pressure.
May enhance the activity of propantheline.
May potentiate the adverse effects of propantheline.
Propantheline may enhance the actions of nitrofurantoin.
May enhance the anticholinergic activity of propantheline.
Propantheline may enhance their actions.
Propantheline delays absorption but increases peak serum levels of ranitidine; relative bioavailability of ranitidine may increase by 23%.
Propantheline may enhance their actions.
Monitoring
- Clinical efficacy (resolution of diarrhea, incontinence, or bradycardia)
- Heart rate and rhythm (if indicated)
- Adverse effects (dry mouth, constipation, urinary retention)
Pharmacokinetics
Absorption
Incompletely absorbed after oral administration due to complete ionization. Food decreases the amount absorbed. Variably absorbed in dogs; dosages require individual titration.
Distribution
Poorly lipid soluble; does not extensively penetrate into the CNS or eye.
Metabolism
Believed to be prevalently metabolized in the GI tract and/or liver.
Elimination
Less than 5% of an oral dose is excreted unchanged in the urine.
Overdose
Toxicity Profile: Because of its quaternary structure, minimal CNS effects are expected following an overdose compared to tertiary amines like atropine.
Treatment:
- Decontamination: If recent oral ingestion, empty gut contents and administer activated charcoal and saline cathartics.
- Supportive Care: Treat clinical signs symptomatically. Fluid therapy and standard treatments for shock may be instituted. Do not use phenothiazines as they may exacerbate anticholinergic effects.
- Antidote (Physostigmine): Controversial. Reserve for extreme agitation/risk of injury, or severe/life-threatening supraventricular and sinus tachycardias.
- Human pediatric dose (reasonable for small animals): 0.02 mg/kg slow IV; may repeat q10 minutes until reversal of toxic effects.
- Note: Physostigmine adverse effects (bronchoconstriction, bradycardia, seizures) may be treated with small doses of IV atropine.
Available products
Formulations
- Tablets (Human-labeled): 7.5 mg, 15 mg
- Injectable: No commercial veterinary product available; must be freshly compounded/filtered from oral tablets for equine IV use
Human-labeled
- Propantheline Bromide Tablets: 7.5 mg & 15 mg (Pro-Banthine®; generic)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Propantheline bromide tablets should be stored at room temperature in tight containers.
Client information
Important: Propantheline is used to treat diarrhea, urinary incontinence, or slow heart rates. It works by relaxing smooth muscles and decreasing gland secretions.
- Dry Mouth: Your pet may experience a dry mouth. This can be relieved by applying small amounts of water to your animal's tongue for 10-15 minutes.
- Monitor for Worsening Signs: Protracted vomiting and diarrhea can be serious. Contact your veterinarian immediately if symptoms are not alleviated or if they worsen.
- Other Side Effects: Watch for constipation, difficulty urinating, or a racing heart rate. Cats may occasionally drool or vomit after taking this medication.
- Administration: Give exactly as prescribed. Do not stop the medication abruptly without consulting your veterinarian.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.