Isosorbide

INTRODUCTION

Indications

Acute treatment of anginal attacks (sublingual only). Prophylactic management of angina pectoris. Treatment of chronic CHF (unlabeled).

Action

Produce vasodilation (venous greater than arterial). Decrease left ventricular end-diastolic pressure and left ventricular end-diastolic volume (preload). Net effect is reduced myocardial oxygen consumption. Increase coronary blood flow by dilating coronary arteries and improving collateral flow to ischemic regions.

Therapeutic Effects: Relief and prevention of anginal attacks.

Adverse Reactions/Side Effects

CNS: dizziness, headache. CV: hypotension, tachycardia, paradoxic bradycardia, syncope. GI: nausea, vomiting. Misc: flushing, tolerance.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Assess episodes of angina pectoris at rest and during exercise. Document whether drug therapy is helpful in reducing the frequency and severity of anginal attacks.

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

• Assess dizziness and syncope 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.

• If used to treat CHF, assess signs and symptoms (dyspnea, rales/crackles, peripheral edema, jugular venous distention, exercise intolerance) to help document whether drug therapy is effective in reducing these symptoms.

• Report signs of drug tolerance during long-term use, as indicated by increased episodes of angina or CHF symptoms. This problem may be resolved by instituting nitrate-free periods; that is, the physician may recommend removing the nitroglycerin patch for several hours each day.

Interventions

• Design and implement aerobic exercise and endurance training programs to improve coronary perfusion, reduce angina, and improve myocardial pumping ability.

• Because of an increased risk of angina and arrhythmias, or in conditions such as CHF, use caution during aerobic exercise and endurance conditioning. Terminate exercise if patient exhibits untoward symptoms (chest pain, shortness of breath, etc.) or displays other criteria for exercise termination (See Appendix L).

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

• To minimize orthostatic hypotension, patient should move slowly when assuming a more upright position.

• If used to treat acute angina, make sure patient brings isosorbide sublingual tablets to all physical therapy appointments, and that this drug is readily available during exercise and other interventions.