Levalbuterol

INTRODUCTION

Indications

Bronchospasm due to reversible airway disease (short-term control agent).

Action

R-enantiomer of racemic albuterol. 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 bronchial smooth muscle. Therapeutic Effects: Relaxation of airway smooth muscle with subsequent bronchodilation. Relatively selective for beta₂ (pulmonary) receptors.

Adverse Reactions/Side Effects

CNS: anxiety, dizziness, headache, nervousness. Resp: increased cough, paradoxical bronchospasm, turbinate edema. CV: tachycardia. GI: dyspepsia, vomiting. Endo: hyperglycemia. F and E: hypokalemia. Neuro: tremor.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• 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 or other health care professional immediately.

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

• Assess heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Report tachycardia or symptoms of other arrhythmias, including palpitations, chest pain, shortness of breath, fainting, and fatigue/weakness.

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

• Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.

• 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. Responses usually begin 15 min after inhalation and peak approximately 90 min after inhalation.

• Because of the risk of cardiovascular stimulation, use caution during aerobic exercise and endurance conditioning. Cardiac effects should be minimal at lower doses or occasional inhaled use. Cardiovascular effects such as arrhythmias, angina pectoris, or increased blood pressure (BP) may occur at higher doses or during excessive use and are caused by inadvertent stimulation of beta receptors on the heart.

Patient/Client-Related Instruction

• Advise patient to not exceed the recommended dose or frequency of inhalations. Contact physician immediately if bronchospasm is not relieved by medication or is accompanied by ...