Albuterol,
Salbutamol
Medication Facts
- Performance enhancing
- Conditionally if misused
- Total hours to clear
- 72
- Frequently used
- Most Prescribed
- ESC ID
- ALBUTE-0027
- Trade names
- Proventil, Ventolin
- Drug type
- Beta-2 adrenergic agonist
- Plasma half-life · hours
- 6 hrs nebulizer, 2 hrs IV
- Equine dosing
- 1 to 2 micrograms per kilogram (μg/kg) delivered via an equine mask. For a standard 1,000 lb (450 kg) horse Severe contraindications when combined with Clenbuteral. ***Recently classified by ESC as A1-Therapeutic with 0 WD due to its abiiity to provide health benefits with its short effiicacy.***
- Cmax · peak plasma concentration
- 0.4 ng/mL
- Tmax · time to peak plasma concentration
- 1
- ESC concentration guidance
- CMAX or 100% of Efficacy
- Primary withdrawal · hours
- 0
- Washout withdrawal · hours
- 48
- ESC control type
- A1 - Generally Controlled - Therapeutic
- Medication report required
- Generally not required, however understand exceptions.
Uses & side effects
Promotes Breathing - Relaxes Airway Muscles
Drug interactions
In veterinary medicine, Albuterol (known internationally as Salbutamol) is highly favored for treating equine asthma because it is a short-acting beta-2 agonist. Unlike clenbuterol, it provides immediate, rapid relief from bronchospasms but has a much shorter duration of action.
PubMed
When delivered via inhalation (either through a liquid nebulizer or a metered-dose inhaler [MDI] with an equine spacer mask like the AeroHippus), its pharmacokinetic profile changes drastically compared to systemic administration.
1. Pharmacokinetics: Half-Life, C
max and T max
When albuterol is inhaled by a horse, it targets the lungs directly. Only about 19% of the inhaled dose enters systemic blood circulation (bioavailability).
Mad Barn
Terminal Plasma Half-Life: Approximately 6 hours (specifically calculated at 6.06 hours in recent pharmacokinetic profiling). However, its actual clinical bronchodilation effect in the lungs is much shorter, typically lasting between 1 and 3 hours (up to 7 hours max).
ResearchGate
T
max
(Time to Peak Concentration): Extremely rapid. Peak concentrations are reached at 0.17 to 0.30 hours (roughly 10 to 18 minutes) after inhalation.
ResearchGate
C
max
(Maximum Plasma Concentration): Exceptionally low because the drug acts locally. Following a standard inhaled dose, the peak plasma concentration is just 0.12±0.06 ng/mL.
ResearchGate
Equine Regulatory Note: Because of its potency, the Racing Medication and Testing Consortium (RMTC) heavily regulates albuterol. It has a strict urine threshold of 1.0 ng/mL, which typically requires a 72-hour withdrawal window before a race for standard doses.
2. Standard Equine Dosing Amount
Albuterol is not officially FDA-approved for animals, so veterinarians prescribe human formulations "extra-label."
Metered-Dose Inhaler (MDI): The most common method. The standard dosage is 1 to 2 micrograms per kilogram (μg/kg) delivered via an equine mask. For an average 1,000 lb (450 kg) horse, this equates to roughly 450 to 900 μg per treatment.
Merck Veterinary Manual
Since a standard human inhaler delivers 90 μg per puff, a veterinarian will usually prescribe 5 to 10 puffs administered every 1 to 6 hours as needed for rescue therapy.
Liquid Nebulizer Solution: If using a liquid nebulizer machine, veterinarians often utilize standard human 0.083% or 0.5% solutions, adjusting the volume to deliver an equivalent microgram dose based on the specific machine's delivery efficiency.
3. Critical Drug Interactions
Because albuterol acts heavily on beta-adrenergic receptors, several key drug interactions must be monitored:
Beta-Blockers (e.g., Propranolol, Timolol): These are direct antagonists to albuterol. If a horse is concurrently on a beta-blocker, it will completely block albuterol's ability to dilate the airways, potentially causing severe bronchospasms.
Other Beta-Agonists (e.g., Clenbuterol): Combining albuterol with oral clenbuterol increases the risk of additive cardiovascular side effects, such as dangerous tachycardia (racing heart rate), severe muscle tremors, sweating, and hypokalemia (low potassium).
Diuretics (e.g., Furosemide / "Lasix"): Furosemide is highly common in racing horses to prevent exercise-induced pulmonary hemorrhage (EIPH). Both furosemide and albuterol can lower blood potassium levels. Using them together risks inducing hypokalemia, which can cause muscle weakness or cardiac arrhythmias.
Tricyclic Antidepressants or MAOIs: Though rarely used in horses, concurrent use can wildly potentiate albuterol's effects on the vascular system, resulting in severe cardiovascular stress.
Contraindications
Clenbuteral, Albuterol, Salbutamol, Ventipulmen, Tri-Hist, Dexamethasone