Labetalol

INTRODUCTION

Indications

Management of hypertension.

Action

Blocks stimulation of beta₁ (myocardial)– and beta₂ (pulmonary, vascular, and uterine)–adrenergic receptor sites. Also has alpha₁-adrenergic blocking activity, which may result in more orthostatic hypotension. Therapeutic Effects: Decreased blood pressure.

Adverse Reactions/Side Effects

CNS: fatigue, weakness, anxiety, depression, dizziness, drowsiness, insomnia, memory loss, mental status changes, nightmares. EENT: blurred vision, dry eyes, nasal stuffiness. Resp: bronchospasm, wheezing. CV: ARRHYTHMIAS, BRADYCARDIA, CHF, PULMONARYEDEMA, orthostatic hypotension. GI: constipation, diarrhea, nausea. GU: erectile dysfunction, decreased libido. Derm: itching, rashes. Endo: hyperglycemia, hypoglycemia. MS: arthralgia, back pain, muscle cramps. Neuro: paresthesia. Misc: drug-induced lupus syndrome.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

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

• Assess routinely for signs of CHF and pulmonary edema, including dyspnea, rales/crackles, weight gain, peripheral edema, and jugular venous distention. Report these signs to the physician immediately.

• Assess blood pressure (BP) periodically and compare to normal values (See Appendix F) to help document antihypertensive effects. Be alert for a fall in BP when patient assumes a more upright position (lying to standing, sitting to standing, lying to sitting). Document orthostatic hypotension and contact physician when systolic BP falls >20 mm Hg, or diastolic BP falls >10 mm Hg.

• Assess symptoms of bronchospasm (wheezing, coughing, tightness in chest). Perform pulmonary function tests to quantify suspected changes in ventilation and respiration (See Appendices I, J, K). Repeated or prolonged bronchoconstriction may require a change in dose or medication (e.g., switch to a more cardioselective beta blocker).

• Watch for signs of hypoglycemia (weakness, malaise, irritability, fatigue) or hyperglycemia (drowsiness, fruity breath, increased urination, unusual thirst). Patients with diabetes mellitus should check blood glucose levels frequently. Medication may mask some signs of hypoglycemia, but dizziness and sweating may still occur.

• Monitor excessive fatigue or weakness. Beta blockers often cause some degree of fatigue and weakness, but any sudden or severe change in muscle strength or energy levels should be reported.

• Assess any back or joint pain to rule out musculoskeletal pathology; that is, try to determine if pain is drug induced rather than caused by anatomic or biomechanical problems.

• Assess signs of paresthesia (numbness, tingling) or muscle cramping. Perform objective tests, including electroneuromyography and sensory testing to document any drug-related neuropathic changes.

• Monitor mood and personality changes, including depression, anxiety, memory loss, or other changes in behavior. Notify physician if these changes become problematic.

• Assess dizziness and drowsiness that might affect gait, balance, and ...