Albuterol, also known as salbutamol, has an indication for the treatment and prevention of bronchospasm (acute or severe) in patients with reversible obstructive airway disease, including exercise-induced bronchospasm.[1][2][3] Without the bronchodilatory effects of albuterol, the individual may suffer catastrophic asphyxiation, making this drug highly desirable to keep on hand for individuals who suffer from recurring obstructive airway symptoms such as in asthma.

Albuterol has an off-label indication for adjuvant treatment of hyperkalemia. [4] [5] Albuterol should not be used as monotherapy and should only be used after successfully attempting treatment first with intravenous calcium to stabilize the cardiac tissue, the rhythm of which is highly dependent on potassium concentrations, followed by administration of insulin and glucose to facilitate intracellular transport of the potassium. [6] Albuterol should not be used as monotherapy because its potassium-lowering effect can be weakened in patients with end-stage renal disease.

Albuterol acts on beta-2 adrenergic receptors to relax the bronchial smooth muscle. It also inhibits the release of immediate hypersensitivity mediators from cells, especially mast cells. Although albuterol also affects beta-1 adrenergic receptors, this is minimal and has little effect on the heart rate.[7][8] In at least one specific study that used immunoliposomes to deliver albuterol to oxytocin receptors, the albuterol was shown to abate uterine contractions. [9] Albuterol, however, is not approved as a tocolytic.

Albuterol comes in a variety of dosing forms and strengths. An aerosol metered-dose inhaler gives 90 mcg (base)/actuation, which is equivalent to 108 mcg of albuterol sulfate. The powder metered-dose inhaler form gives the same values as the aerosol metered-dose inhaler. Albuterol also is offered in 2 mg and 4 mg tablets. Extended-release tablets are available in 4 mg and 6 mg versions. As a nebulized solution, albuterol is available in 0.083%, 0.5%, 0.63 mg/3mL, and 1.25 mg/3 mL dosage forms. There is also an available oral syrup in a 2 mg/5 mL concentration.[10]

Several forms of albuterol are accepted for the treatment of bronchospasm. A nebulized solution of 2.5 mg two or three times a day as needed is acceptable for quick relief of symptoms. Dosing of 1.25 to 5 mg every four to eight hours as needed of the nebulized solution is also effective for quick relief of symptoms. For the powdered and aerosol metered-dose inhaler, the advice to use one or two puffs of 90 mcg every four to six hours depending on the patient, but it is advised not to exceed 12 puffs within 24 hours. For tablet and syrup formulations, 2 to 4 mg every 6 to 8 hours is recommended with the advisory not to exceed 32 mg in one day. The extended-release tablets are taken in either 4 mg or 8 mg doses (depending on the patient’s need) every 12 hours with the limit of 32 mg per day.[11]

For the treatment of acute or severe bronchospasm, it is advisable to use a nebulizer solution with a concentration of 2.5 to 5 mg every 20 minutes for three cycles, followed by repeat nebulizer treatments of 2.5 to 10 mg every 1 to 4 hours as needed. Treatment can be maintained with continuous nebulizer treatments every 10 to 15 minutes. If treating with a metered-dose inhaler, 4 to 8 puffs of 90 mcg every 20 minutes for up to 4 hours is a standard practice followed by 4 to 8 puffs every 1 to 4 hours as needed.

For exercise-induced bronchospasm, the recommendation is to treat with aerosol or powder metered-dose inhaler before exercise. Two puffs of 90 mcg (for a total of 180 mcg) taken 15 to 20 minutes prior to exercise may help prevent symptoms.

For the treatment of pediatric patients, age becomes a significant factor in the course of treatment. For children under two years old, nebulizer solution with dosing by weight of 0.2-0.6 mg/kg/day divided into either a 4- or 6-hour cycle. For children two years old and older, a nebulizer solution dosing of the 2.5 mg/0.5 mL solution is given every 6 to 8 hours with a maximum of 10 mg given in any 24 hours.

The use of aerosol metered-dose inhalers in the pediatric population under the age of 4 years old has not had research conducted. The dosing recommendation for four years and older is 90 to 180 mcg (1 to 2 puffs) every 4 to 6 hours.

The use of powder metered-dose inhalers in the pediatric population under the age of 4 years old has not been studied. Dosing recommendation for four years and older to take 180 mcg (2 puffs) every 4 to 6 hours not to exceed 12 puffs within 24 hours.[2]

The dosing of albuterol tablets in pediatric patients under six years old is 0.3 to 0.6 mg/kg/day divided into three treatments given every 8 hours throughout the day. It is advised not to exceed 12 mg/day. For those ages 6 to 12, 2 mg every 6 to 8 hours is the recommended dosage with a daily maximum of 24 mg per day. For pediatric patients over the age of 12, 2 to 4 mg given every 6 to 8 hours with a daily maximum of 32 mg.[12]

Extended-release albuterol tablets are not recommended for those under the age of 6. For pediatric patients between 6 and 12 years of age, the recommendation is for a dose of 4 mg every 12 hours is given, not to exceed 24 mg in 24 hours. For pediatric patients over the age of 12, 8 mg taken every 12 hours is the recommended dose.

The syrup formulation has not been studied in children under the age of 2. For patients between the ages of 2 and 6, the dose is 0.1 mg/kg every 8 hours. This dosing can increase if needed, to 0.2 mg/kg every 8 hours. For those 6 to 14 years of age, 2 mg taken every 6 to 8 hours should suffice. For pediatric patients over the age of 14, 2 to 4 mg taken every 6 to 8 hours is the recommended dose with a daily maximum of 32 mg/day.

The primary adverse effects of albuterol therapy are tremors and nervousness, mostly seen in children who are 2 to 6 years of age, though can be seen at any age. Tremors are the result of activation of the beta-2 receptors found on the motor nerve terminals which increases intracellular cAMP. These side effects occur in approximately one in every five patients. Other side effects include insomnia and nausea, which occur in approximately 1 in every ten patients. Less common adverse effects may include fever, bronchospasm, vomiting, headache, dizziness, cough, allergic reactions, otitis media, epistaxis, increased appetite, urinary tract infections, dry mouth, gas, hyperhidrosis, pain, dyspepsia, hyperactivity, chills, lymphadenopathy, ocular pruritus, sweating, conjunctivitis, and dysphonia. Albuterol also has been shown to increase blood pressure and may cause hypokalemia. Increased blood glucose concentrations and prolonged QTc interval and ST-segment depression have occurred, although rarely.[13][14]

Hypersensitivity is a contraindication for albuterol. Also, if a patient is severely hypersensitive to milk protein, it is advised to avoid the use of albuterol.