Ipratropium Bromide
Ipratropium bromide
Also known as: Atrovent · DuoNeb · Combivent · Sch-1000
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
Small Mammals
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| As a bronchodilator in rats | one puff into nebulization chamber | Inhalation | twice daily | — | 🌎 NA |
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Adjunctive treatment of RAO, heaves (mild to moderate disease) | 180 micrograms inhaled aerosol | Inhalation | q4-6h | 14 days | 🌎 NA |
| Adjunctive treatment of RAO/heaves (moderate to severe disease) | 90-180 micrograms inhaled via Equine Aeromask or Equine Haler | Inhalation | every 6 hours | — | 🌎 NA |
| Adjunctive treatment of foals with severe bronchospasm | 2-3 micrograms/kg via aerosol | Inhalation | q6-8h | — | 🌎 NA |
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Locally administered (inhaled) ipratropium bromide is an antimuscarinic agent used for the adjunctive treatment of bronchospastic conditions, such as Recurrent Airway Obstruction (RAO) in horses and chronic respiratory diseases in small animals.
Clinical Pearls:
- Ipratropium is a quaternary ammonium derivative of atropine. Because of its highly polar nature, it is poorly absorbed into the systemic circulation and does not readily cross the blood-brain barrier, significantly reducing the risk of systemic anticholinergic side effects.
- It has a relatively short duration of activity and may need to be administered frequently.
- While there is limited formal pharmacokinetic data in small animals, it is generally considered safe and effective as an adjunctive bronchodilator.
Mechanism of action
Ipratropium acts as a competitive antagonist of acetylcholine at muscarinic receptors in the bronchial smooth muscle.
- Mechanism: Antagonizes acetylcholine → Prevents increases in intracellular cyclic guanosine monophosphate (cGMP) → Reduces bronchial smooth muscle constriction.
- Advantage over Atropine: Unlike atropine, ipratropium does not reduce mucociliary clearance, making it highly beneficial for patients with respiratory diseases where clearing airway secretions is critical.
Safety & warnings
Contraindications
- Hypersensitivity to ipratropium or other atropine derivatives
Adverse effects
- Tracheal or bronchial irritation (coughing)
- Allergic responses
- Mild anticholinergic effects (e.g., dry mouth, tachycardia) in rare cases
Precautions
Use with caution in conditions where antimuscarinics may be harmful, including narrow-angle glaucoma, bladder-neck obstruction, or prostatic hypertrophy. FDA Category B for pregnancy in humans; likely safe to use during nursing.
Drug interactions
May cause additive antimuscarinic effects
May have additive therapeutic bronchodilatory effects
Monitoring
- Clinical efficacy (improvement in respiratory rate, effort, and lung sounds)
Pharmacokinetics
Half-life
Absorption
Minimal drug is absorbed into the systemic circulation because the medication is inhaled and acts locally.
Distribution
Acts locally within the respiratory tract.
Metabolism
Not extensively detailed in the monograph; primarily local action.
Elimination
In humans, the elimination half-life is about 2 hours.
Overdose
Overdosage is unlikely to be a cause for concern. The drug is not well absorbed orally or after inhalation. Oral LD50 values for laboratory animals were greater than 1 gram/kg.
Available products
Formulations
- Solution for Inhalation
- Aerosol for Inhalation (Metered Dose Inhaler)
Human-labeled
- Ipratropium Bromide Solution for Inhalation: 0.02% (500 micrograms/vial) preservative free in 25 & 60 unit-dose vials (2.5 mL UD 'nebs')
- Ipratropium Bromide Aerosol for Inhalation: each actuation delivers 17 micrograms in 12.9 grams metered dose inhaler w/mouthpiece (approx 200 inhalations); Atrovent HFA
- Combination products: DuoNeb (with albuterol as nebs), Combivent (with albuterol as MDI)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
The solution for inhalation should be stored at room temperature and protected from light. Keep in foil pouch until time of use. The metered dose inhalers should be stored at room temperature. The solution for nebulization may be mixed with albuterol or metaproterenol if used within one hour.
Client information
Important Note: This medication is not for treating an acute asthma attack; it is intended for maintenance treatment to keep airways open over time.
- Inhaler Usage: If using the aerosol metered dose inhalers (MDI), do not use after 200 inhalations (puffs) even if there appears to be medication remaining, as the active ingredient concentration cannot be assured.
- Handling: Do not shake the HFA canister before using.
- Administration: Ensure you are comfortable with the administration device (e.g., Aeromask, nebulization chamber) to ensure your pet receives the full dose.
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.