Methyldopa

INTRODUCTION

Indications

Management of moderate-to-severe hypertension (with other agents).

Action

Stimulates CNS alpha-adrenergic receptors, producing a decrease in sympathetic outflow to heart, kidneys, and blood vessels. Result is ↓ blood pressure and peripheral resistance, a slight ↓ in heart rate, and no change in cardiac output. Therapeutic Effects: Lowering of blood pressure.

Adverse Reactions/Side Effects

CNS: sedation, ↓ mental acuity, depression. EENT: nasal stuffiness. CV: MYOCARDITIS, bradycardia, edema, orthostatic hypotension. GI: DRUG-INDUCED HEPATITIS, diarrhea, dry mouth. GU: erectile dysfunction. Hemat: eosinophilia, hemolytic anemia. Misc: fever.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Watch for signs of myocarditis, including chest pain, arrhythmias, fatigue, shortness of breath, peripheral/pulmonary edema, and difficult or labored breathing. Report these signs to the physician immediately.

• Be alert for signs of drug-induced hepatitis, including anorexia, abdominal pain, severe nausea and vomiting, yellow skin or eyes, skin rashes, flu-like symptoms, and muscle/joint pain. Report these signs to the physician immediately.

• Assess blood pressure (BP) periodically and compare to normal values (See Appendix F). Document whether drug therapy is successful in controlling hypertension. Also measure 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 heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Report an unusually slow heart rate (bradycardia) or signs of other arrhythmias, including palpitations, chest discomfort, shortness of breath, fainting, and fatigue/weakness.

• Assess peripheral edema using girth measurements, volume displacement, and measurement of pitting edema (See Appendix N). Report increased swelling in feet and ankles or a sudden increase in body weight due to fluid retention.

• Monitor signs of eosinophilia (fatigue, weakness, myalgia) and hemolytic anemia (unusual fatigue, shortness of breath, dizziness, headache, coldness in your hands and feet, pale skin, chest pain). Report these signs to the physician.

• Be alert for signs of depression, decreased mental alertness, or other changes in mood and behavior. Notify physician if these changes become problematic.

Interventions

• Because of the risk of arrhythmias and abnormal BP responses, use caution during aerobic exercise and other forms of therapeutic exercise. Assess exercise tolerance frequently (BP, heart rate, fatigue levels), and terminate exercise immediately if any untoward responses occur (See Appendix L).

• Avoid physical therapy interventions that cause systemic vasodilation (large whirlpool, Hubbard tank). Additive effects of this drug and the intervention may cause a dangerous fall in BP.

• To minimize orthostatic hypotension, advise patient to move slowly when assuming a more upright ...