Albuterol

INTRODUCTION

Indications

Used as a bronchodilator to control and prevent reversible airway obstruction caused by asthma or COPD. Inhaln: Used as a quick-relief agent for acute bronchospasm and for prevention of exercise-induced bronchospasm. PO: Used as a long-term control agent in patients with chronic/persistent bronchospasm.

Action

Binds to beta₂-adrenergic receptors in airway smooth muscle, leading to activation of adenyl cyclase and increased levels of cyclic-3,′,5,′ adenosine monophosphate (cAMP). Increases in cAMP activate kinases, which inhibit the phosphorylation of myosin and decrease intracellular calcium. Decreased intracellular calcium relaxes smooth muscle airways. Relaxation of airway smooth muscle with subsequent bronchodilation. Relatively selective for beta₂ (pulmonary) receptors. Therapeutic Effects: Bronchodilation.

Adverse Reactions/Side Effects

CNS: nervousness, restlessness, tremor, headache, insomnia (Pedi: occurs more frequently in young children than adults), hyperactivity in children. CV: chest pain, palpitations, angina, arrhythmias, hypertension. GI: nausea, vomiting. Endo: hyperglycemia. F and E: hypokalemia.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Assess pulmonary function at rest and during exercise (see Appendixes I, J, K) to document effectiveness of medication in controlling bronchospasm.

• Monitor signs of paradoxical bronchospasm (wheezing, cough, dyspnea, tightness in chest and throat), especially at higher or excessive doses. If condition occurs, advise patient to withhold medication and notify physician immediately.

• Assess blood pressure periodically and compare to normal values (see Appendix F). Report a sustained increase in blood pressure (hypertension) to the physician.

• Assess heart rate, ECG, and heart sounds, especially during exercise (see Appendixes G, H). Report any rhythm disturbances or symptoms of increased arrhythmias, including palpitations, chest discomfort, shortness of breath, fainting, and fatigue/weakness.

• Monitor and report signs of CNS toxicity, including nervousness, restlessness, tremor, or hyperactivity. Sustained or severe CNS signs may indicate overdose or excessive use of this drug.

• Monitor signs of hyperglycemia, including drowsiness, fruity breath, increased urination, and unusual thirst. Patients with diabetes mellitus should check blood glucose levels frequently.

• Monitor and report any muscle weakness, aches, or cramps that might indicate low potassium levels (hypokalemia).

Interventions

• When implementing airway clearance techniques or respiratory muscle training, attempt to intervene when the airway is maximally bronchodilated. Peak responses typically occur 60–90 min after inhalation or 2–3 hr after oral administration.

• Use caution during aerobic exercise and endurance conditioning because of the risk of cardiovascular stimulation. Cardiac effects should be minimal at lower oral doses or occasional inhaled use. Cardiovascular effects such as arrhythmias, angina pectoris, or increased blood pressure may occur at higher doses or during excessive use, ...