tailieunhanh - CLINICAL PHARMACOLOGY 2003 (PART 25A)

Hypertension and coronary heart disease (CHD) are of great importance. Hypertension affects above 20% of the total population of the USA with its major impact on those over age 50. CHD is the cause of death in 30% of males and 22% of females in England and Wales. Management requires attention to detail, both clinical and pharmacological. The way drugs act in these diseases is outlined and the drugs are described according to class. • Hypertension and angina pectoris: how drugs act • Drugs used in both hypertension and angina Diuretics Vasodilators organic nitrates, calcium channel inhibitors, angiotensin. | 23 SECTION 5 Arterial hypertension angina pectoris myocardial infarction SYNOPSIS Hypertension and coronary heart disease CHD are of great importance. Hypertension affects above 20 of the total population of the USA with its major impact on those over age 50. CHD is the cause of death in 30 of males and 22 of females in England and Wales. Management requires attention to detail both clinical and pharmacological. The way drugs act in these diseases is outlined and the drugs are described according to class. Hypertension and angina pectoris how drugs act Drugs used in both hypertension and angina Diuretics Vasodilators organic nitrates calcium channel blockers ACE inhibitors angiotensin II-receptor antagonists Adrenoceptor blocking drugs a and 3 Peripheral sympathetic nerve terminal Autonomic ganglion-blocking drugs Central nervous system Treatment of angina pectoris Acute coronary syndromes and myocardial infarction Arterial hypertension Sexual function and cardiovascular drugs Phaeochromocytoma Hypertension how drugs act Consider the following relationship Blood pressure - cardiac output x peripheral resistance Therefore drugs can lower blood pressure by Dilatation of arteriolar resistance vessels. Dilatation can be achieved through direct relaxation of vascular smooth muscle cells by stimulation of nitric oxide NO production or by blocking suppressing endogenous vasconstrictors noradrenaline norepinephrine and angiotensin. Dilatation of venous capacitance vessels reduced venous return to the heart preload leads to reduced cardiac output especially in the upright position Reduction of cardiac contractility and heart rate. Depletion of body sodium. This reduces plasma volume transiently and reduces arteriolar response to noradrenaline norepinephrine Modem antihypertensive drugs lower blood pressure with minimal interference with homeostatic control . change in posture exercise. 461 SECTION 5 23 ARTERIAL H Y P E R T E N S I O N A N G I N A PECTORIS Ml Angina .