Vetdrugs 2.0Salbutamol, also called albuterol, is a short-acting beta-2 adrenergic agonist used to relieve reversible bronchoconstriction. It provides rescue bronchodilation in dogs, cats and horses with compatible lower-airway disease. Amounts are expressed as salbutamol/albuterol base, including preparations that contain the sulfate salt.
Inhaled delivery targets the airways and generally acts more rapidly than oral administration. Its principal effect is relaxation of bronchial smooth muscle, making it useful for intermittent rescue bronchodilation within the broader management of airway disease.
Group
Short-acting beta-2 adrenergic bronchodilator
Mechanism of Action
Salbutamol stimulates beta-2 receptors on bronchial smooth muscle. Receptor activation couples through stimulatory G proteins to adenylyl cyclase, increasing intracellular cyclic AMP. The resulting signaling reduces contractile activity and relaxes airway smooth muscle, lowering resistance to airflow when bronchospasm is reversible.
Beta-2 stimulation may also reduce release of some mediators from mast cells, but this does not substitute for anti-inflammatory treatment in asthma or other inflammatory airway disease. Bronchodilation cannot correct obstruction caused entirely by fixed structural narrowing, mucus plugging or disease outside the lower airways.
Systemic beta-adrenergic exposure can increase heart rate, shift potassium into cells and increase blood glucose. The racemic drug contains R and S isomers, with the R isomer principally responsible for bronchodilation. Levalbuterol contains the R isomer alone and is a distinct preparation rather than an automatically interchangeable strength.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Bronchospasm | 20–50 mcg/kg | PO | Every 6–8 h | Do not use in: Pregnancy when uterine relaxation is undesirable; Oral doses are largely extrapolated; inhaled rescue treatment has a different regimen. |
| Bronchospasm | 100 mcg/kg | PO | Every 6 h | Do not use in: Pregnancy when uterine relaxation is undesirable; Reported upper oral dose, not an initial-dose recommendation. Monitor cardiovascular effects and potassium. |
| Bronchospasm | 20 mcg/kg | PO | Every 12 h | Up to 5 days; Lower initial oral course; if ineffective without adverse effects, a separately described escalation is 50 mcg/kg every 8-12 hours. Reduce to the lowest effective regimen. |
| Bronchospasm | 50 mcg/kg | PO | Every 8–12 h | Alternative oral regimen after response and adverse-effect assessment. |
| Bronchospasm | 2.5 mg/animal | INHALATION | Every 6 h | Reported nebulization regimen for an approximately 27 kg dog, not a universal canine fixed dose: 0.5 mL of 5 mg/mL solution added to 4 mL saline. Adjust the clinical plan for patient and device. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Bronchospasm | 20–50 mcg/kg | PO | Every 6–8 h | Do not use in: Pregnancy when uterine relaxation is undesirable; Oral doses are largely extrapolated; inhaled rescue treatment has a different regimen. |
| Bronchospasm | 100 mcg/kg | PO | Every 6 h | Do not use in: Pregnancy when uterine relaxation is undesirable; Reported upper oral dose, not an initial-dose recommendation. Monitor cardiovascular effects and potassium. |
| Bronchospasm | 90–180 mcg/animal | INHALATION | As needed | One or two actuations only for a 90 mcg/actuation device, delivered through a fitted spacer and mask. In a crisis, monitored repeat treatment every 15 minutes for 3-4 treatments is described; reassess response and oxygenation. Continue appropriate anti-inflammatory treatment. |
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Bronchospasm | 360 mcg/animal | INHALATION | As needed | Do not use in: Pregnancy when uterine relaxation is undesirable; Adult horses: up to four treatments daily using a suitable adaptor. Equivalent to four actuations only for a device delivering 90 mcg base per actuation. |
| Bronchospasm | 0.01–0.02 mg/kg | PO | Every 8–12 h | Do not use in: Pregnancy when uterine relaxation is undesirable; Foals; monitor heart rate and clinical response. |
| Bronchospasm | 2–3 mcg/kg | INHALATION | As needed | Alternative delivered-dose regimen using an equine mask and spacer; determine the device-specific actuation count. |
| Bronchospasm | 0.8–2 mcg/kg | INHALATION | As needed | Separate lower inhaled-dose regimen for equine airway obstruction; assess response and device delivery. |
| Bronchospasm | 450–900 mcg/animal | INHALATION | As-needed alternative; no more than four treatments per week unless used with a corticosteroid. Five to ten actuations applies only to a 90 mcg/actuation device. |
Indications
- Rapid relief of reversible bronchospasm in dogs and cats with compatible lower-airway disease, including rescue treatment during acute exacerbations.
- Short-term bronchodilation in horses with equine asthma or other reversible bronchoconstrictive airway disease.
- Adjunctive rescue bronchodilation during management of inflammatory airway disease.
- Selected oral bronchodilator treatment when systemic delivery is appropriate.
Contraindications
- Avoid in pregnancy when inhibition of uterine contractions is undesirable.
- Use cautiously with tachyarrhythmias, cardiovascular disease, hypokalemia or hyperglycemia.
- Do not administer to animals intended for food under these regimens.
- Known salbutamol or formulation hypersensitivity.
- Use cautiously in hyperthyroidism, hypertension, seizure disorders and diabetes.
- Frequent scheduled racemic albuterol exposure may aggravate feline airway inflammation; reserve it principally for rescue and reassess control if frequent doses are required.
Interactions
- Other sympathomimetics can increase tachycardia and arrhythmia risk.
- Nonselective beta blockers can oppose bronchodilation.
- Potassium-depleting drugs can increase hypokalemia risk.
- Digoxin and inhalation anesthetics may increase arrhythmia risk.
- Tricyclic antidepressants and monoamine oxidase inhibitors may potentiate cardiovascular effects.
Adverse effects
- Tachycardia, tremors, agitation or arrhythmias.
- Hypokalemia and hyperglycemia with substantial systemic exposure.
- Inhibition of uterine contractions near term.
Toxicity
Excess exposure, including chewing an inhaler, can cause marked tachycardia, tremors, arrhythmias and hypokalemia. Monitor ECG, potassium and glucose; correct abnormalities according to measured values and clinical response.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Ventolin Syrup 2 mg/5 mL Contains salbutamol sulfate equivalent to 2 mg salbutamol base per 5 mL. | Oral Liquid | 2 mg / 5 mL | PO |
| Albuterol Sulfate Syrup 2 mg/5 mL (Quagen) Quagen Pharmaceuticals LLC Each 5 mL contains 2 mg albuterol base supplied as 2.4 mg albuterol sulfate. | Oral Liquid | 2 mg / 5 mL | PO |
| Albuterol Inhalation Solution USP 0.083% (Mylan) The Ritedose Corporation Unit-dose nebulizer solution; potency is expressed as albuterol base. Store in the pouch protected from light at 2-25 C. Not for injection. | Other | 2.5 mg / 3 mL | INHALATION |
| Albuterol Inhalation Solution USP 0.5% (Rising) Nephron Pharmaceuticals Corporation Concentrated nebulizer solution; potency is expressed as albuterol base. Dilute for nebulization. Store in pouch protected from light at 20-25 C; not for injection. | Other | 5 mg / mL | INHALATION |
| Ventolin Respirator Solution 0.5% Concentrated nebulizer solution; dilute according to the selected protocol and device. Not an injectable preparation. | Other | 5 mg / mL | INHALATION |
Monitoring and Administration
Monitor respiratory effort and rate, auscultation and clinical response; measure oxygenation or blood gases when indicated. Monitor heart rate/rhythm and potassium in susceptible patients.
A device delivering 90 mcg albuterol base per actuation is different from one delivering 100 mcg. Do not infer puff counts from canister mass or substitute sulfate mass for base mass.
A described equine emergency approach uses 360 mcg inhaled, with monitored repeats at 15-minute increments for up to two hours during severe obstruction, followed by reassessment and a less frequent schedule. Rapid tolerance can develop with sole beta-agonist treatment; concurrent anti-inflammatory treatment remains important.
A canine oral dose printed as 50 mg/kg in older references is specifically identified as an overdose in the supplied material; 50 mcg/kg is 0.05 mg/kg. Never treat these units as interchangeable.
Separate feline rescue approaches include 90 mcg inhaled every 30 minutes as needed in an emergency with oxygen and anti-inflammatory treatment, and two actuations through a spacer with 7–10 seconds of breathing for intermittent signs. One account permits crisis repeats every 30 minutes for 2–4 hours. These are distinct from the shorter-repeat course already recorded; do not merge them into an unrestricted repeat schedule.
Do not puncture or expose aerosol canisters to excessive heat. Shake and prepare the device as directed and confirm delivered amount per actuation. Ventolin Evohaler is listed in official Pakistan product information; Asthalin inhaler is identified by Cipla and salbutamol inhalers are listed by Sri Lanka SPC. Metered-actuation strengths require device-specific interpretation and are not encoded as mg/mL preparations.