Hypertension Management Course Materials

HYPERTENSION MANAGEMENT (PHARMACHOLOGICAL AND LIFESTYLE) Hypertension • • • • • Greatly increased risk of stroke and MI Diuretics and beta blockers à reduced mortality Treatment implemented should take into account their other risk factors o Unmodifiable risk factors (diabetes or renal disease) or those with evidence of end-organ damage (LV hypertrophy) à more aggressive therapy may be required o Modifiable risk factors = smoking, lipids, alcohol, salt, lack of exercise, overweight Vessel rarefaction = reduced capillaries in high BP Old age → static state of vascular tone Treatment targets • • • Target volume Target systemic tone o SNS e.g. Beta blockers, Ca channel blockers (cause smooth muscle relaxation) o VSM contraction o Local constrictions Renin and angiotensin system – local tone and salt retention Classes of drugs • • • • • • • Diuretics Antiadrenergic agents Vasodilators Angiotensin converting enzyme inhibitors Angiotensin receptor antagonists Calcium channel antagonists Mineralocorticoid receptor antagonists Implementing hypertension medication • • • • • • • 1st line treatment 2nd line treatment = different class to 1st line 3rd line treatment – by now must have a diuretic o Reduce HR response to fluid loss: ▪ Beta blocker ▪ Antiadrenergic ▪ Both alpha and beta blocker If you need a 4th line drug you have refractory hypertension If you need >5th line drug you have resistance hypertension Look for compelling indication e.g. a drug that has side-effects that help with other conditions e.g. migraines Look for contraindication e.g. asthma, pregnancy, drug interactions Diuretics • Elevates rate of urination → reduced blood volume → reduced cardiac output → reduced BP • Diuretics act in kidney to influence salt and water reabsorption: increase Na+ excretion, thus reduce plasma volume • 3 types: o Loop diuretics act in loop of Henle o Thiazide diuretics act in distal convoluted tubule o K+ sparing diuretics act in collecting tubule Beta-adrenoceptor antagonists – Beta blockers • • Block action of endogenous adrenaline and noradrenaline on Beta receptors → block effect of adrenaline/noradrenaline on myocardium → reduced rate and force of cardiac contraction Reduce renin release from kidney • Combining beta blockers and a diuretic = best 1st line treatment o Cheap and effective → most widely available in the world o USA guidelines α2 adrenergic receptor agonists • • • • Inhibits adenylyl cyclase activity → reduce brainstem vasomotor centre-mediated CNS activation o Used as antihypertensives, sedatives and treatment of opiate and alcohol withdrawal symptoms Clonidine (mixed alpha2-adrenergic and imidazoline-I1 receptor agonist) Methyldopa Physiotens: moxonidine ACE inhibitors • • • • • • Block conversion of AI to AII → reduce AII-induced vasoconstriction, aldosterone release and Na retention Block breakdown of bradykinin Used in hypertension, heart failure, post-MI Should not be used in pregnancy, renanl artery stensosis ACEI include captopril, enalapril, and lisinopril (side effects = severe hypotension, hyperkalaemia, renal impairment) AII Antagonists block the effects of circulating and tissue AII by blocking the binding of AII to the AII type 1 receptor (known as AT1 receptor), which is responsible for the cardiovascular actions of AII. Blood pressure is lowered as the total peripheral resistance is decreased, while cardiac output and heart rate are maintained. These drugs block the effects of AII more selectively than ACEI and cause relatively few adverse effects. 4th line treatment • Add a calcium channel blocker → vascular smooth muscle relaxation → vasodilation → reduced BP o Dihydropyridine: reduces systemic vascular resistance and arterial pressure o Non-dihydropyridine: reduces myocardial O2 demand o Pharmacokinetics of calcium channel antagonists (blockers): • • Alternatively: ACE inhibitor Additional treatment: another vasodilator e.g. monoxidil Original treatment options • • • • • • • • Thiocyanate Veratrum viride Sympathectomy Pentaquine (Ganglion blocker) Hydaralazine (1950) Hexamethomium Reserpine Chlorthiazide Recommended targets Adults ≥ 65 years • Unless there is diabetes and/or renal insufficiency and/or proteinuria (≥0.25g/day) • Adults < 65 years, and/or • Adults with diabetes, and/or • Adults with renal insufficiency, and/or <140/90 <130/85 • Adults with proteinuria (≥0.25g/day) Adults with proteinuria > 1g/day (in people with or without targets) <125/75 Lifestyle modifications • • • • • • • • Lose weight – 5kg reduction (reduces IGT risk ) tied in with reductions in BP Limit alcohol 2 std drinks per day (men) 2 std drink for women Increase aerobic exercise 30-45 mins per day Reduce sodium intake to <100mmol/lday =2.4 g sodium, or 6g sodium chloride Maintain adequate potassium intake (90 mmol/day) Maintain calcium and magnesium intake Stop smoking and reduce dietary saturated fat and cholesterol for overall cardiovascular health Diets • • • • • • Low salt Low calorie 1904 low protein, rice-fruit diet Normal protein, salt restricted DASH Aus- DASH