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RELIEVING THE PRESSURE. Medications for Treating Hypertension Jeannie Collins Beaudin, RPh Keswick Pharmacy. WIDESPREAD PROBLEM. CANADIAN STATISTICS: More than 1 in 5 adults have hypertension (22%) 46% of Canadians age 55-65 42% - No diagnosis Only 16% are controlled
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RELIEVING THE PRESSURE Medications for Treating Hypertension Jeannie Collins Beaudin, RPh Keswick Pharmacy
WIDESPREAD PROBLEM... CANADIAN STATISTICS: • More than 1 in 5 adults have hypertension (22%) • 46% of Canadians age 55-65 • 42% - No diagnosis • Only 16% are controlled • 9% of those with diabetes (more stringent targets)
IMPORTANCE OF NURSES’ ROLE • Nurses have: • Frequent patient contact • Patient trust • Favourable financial model • Educational role
...PART OF THE PICTURE • METABOLIC SYNDROME: • Hypertension • Insulin resistance • Hypercholesterolemia • Abdominal weight gain • Prothrombic state • Pro-Inflammatory state • All are risk factors for cardiovascular disease • #1 cause of death
CAUSES OF METABOLIC SYNDROME • Obesity • Inactivity • Poor diet • Unknown genetic factors • Stress? • Cortisol • Increases BP, heart rate, lipids, blood glucose • Weight gain around waist
KEY CHEP MESSAGES... • Need to assess overall CVD risk • Combination of drug therapy and lifestyle changes are most effective • Monitor regularly when above target • Regular screening for all adults • Focus on adherence
ADHERENCE • Assess regularly • Encourage patients to bring bottles • Check date filled and amount remaining • Fit to daily schedule • Strive for once daily dosing • Long-acting formulas • Fixed-dose combinations • Fewer pills per day • Often more expensive, not covered • Use unit-of-dose packaging • Improve patient education • Encourage patient involvement in monitoring
TYPES OF HYPERTENSION MEDICATIONS • Those that affect hormone systems • Beta-blockers • ACE Inhibitors (angiotensin converting enzyme inhibitors) • ARBs (angiotensin receptor blockers • Those that affect electrolytes • Fluid balance • Diuretics • Vasodilation • Calcium channel blockers
ABCs OF HYPERTENSION MEDS • Angiotensin Converting Enzyme Inhibitors (ACE-I), Angiotensin Receptor Blockers (ARB) • Beta-Blockers • Calcium channel blockers (CCBs) • Diuretics • “Everything else”... Alpha-Blockers
ACE-Inhibitors • End with “-pril” • Block the enzyme that converts Angiotensin I to Angiotensin II • Also reduce morbidity/mortality of • HF, angina, stroke, DM neuropathy • Generally well tolerated • 25% can develop dry cough • ACE enzyme also block breakdown of bradykinin (xs causes cough) • Teratogenic – caution in pre-menopausal women
ANGIOTENSIN RECEPTOR BLOCKERS (ARBs) • End with “-sartan” • Block the effect of Angiotensin II instead of blocking production • Actions similar to ACE-I • But does not affect bradykinin • No cough side effect • Better tolerated • More expensive • Also teratogenic
BETA-BLOCKERS • End with “-olol” • “Beta adrenergic receptor blockade” • Block beta receptors for adrenalin • Beta-1, Beta-2 receptors • Beta-1 - heart, blood vessels • Beta-1 selective BB’s (e.g. Atenolol, Metoprolol) • Beta-2 - lungs, brain • Non-selective BB’s (e.g. Propranolol, Nadolol)
BETA-BLOCKERS BETA-2: • Lungs • Bronchodilation • Site of action of Salbutamol (beta-agonist) • Brain • Dreaming • Migraine • Beta-blockers can decrease frequency
BETA-BLOCKERS • Block action of adrenalin and beta(adrenalin) agonists on lungs: • Can worsen bronchospasm, asthma • Block action of inhaled Salbutamol • Can be useful for blocking essential tremor
BETA-BLOCKERS • Disadvantages: • Slow heart rate, lower blood pressure (fatigue) • Reduce blood flow to extremities (cold hands, feet, impotence) • Less heart-selective can increase dreaming • Increase risk of diabetes (especially with diuretics) • Not recommended over 65 years • Advantages: • Reduce mortality post-MI • Also useful for HF, angina • Non-cardio selective can prevent migraine • Inexpensive
CALCIUM CHANNEL BLOCKERS • Calcium is necessary for smooth muscle contraction • Calcium enters cells via tiny channels • Blocking calcium channel inhibit muscle contraction • Vasodilation • Reduced force of heart muscle contraction • Affect heart, blood vessels – not skeletal muscle
CALCIUM CHANNEL BLOCKERS Three types: • Dihydropyridines (DRPs) - end with “-dipine” • Amlodipine, Felodipine, Nifedipine • Phenylalkylamines • Verapamil • Benzothiazepines • Diltiazem • Last 2 have similar characteristics • Often referred to as “non-dihydropyridines” (non-DRPs) • Essentially 2 classes now: DRPs and non-DRPs
CALCIUM CHANNEL BLOCKERS DIFFERENT SITES OF ACTION: • DRPs (-dipines) act mainly on blood vessels “vasodilating” • Excess relaxation -> peripheral edema • Adversely affect renal function in diabetes • Non-DRPs (verapamil, diltiazem) also act on heart “modulating” • Verapamil has the strongest effect on heart • Diltiazem is “middle of the road” • Both slow conduction of impulse through AV node • Caution with 2nd and 3rd degree heart block • Avoid in heart failure • Renal protective • Preferable if risk of diabetes or kidney damage
CALCIUM CHANNEL BLOCKERS • No effect on: • Insulin secretion or action • Blood glucose • Plasma protein levels • Potassium balance • Magnesium balance • Grapefruit interaction • Amlodipine, felodipine
CALCIUM CHANNEL BLOCKERS • Short-acting nifedipine • Spike in norepinephrine, transient rise in plasma renin • Reflex tachycardia, BP rise • No longer used for emergency hypertension
DIURETICS • End with “-ide” • Hydrochlorothiazide, indapamide, furosemide • Act on kidney to increase fluid excretion • Reduced blood volume -> reduced pressure • Thiazides – act on tubules • Furosemide - “Loop” diuretic, more potent • Most cause loss of potassium • Increased risk of electrolyte imbalances • Exceptions “potassium sparing”: • Spironolactone (Aldactone) • Amiloride (in Moduret, Apo-Amilzide), • Triamterene (in Dyazide, Apo-Triazide, Nov0-Triamzide )
DIURETICS • Many side effects: • Lethargy, reduced exercise tolerance, polyuria • Hypokalemia • Skeletal muscle weakness, GI hypomotility (ileus, constipation) • Leg cramps, arrhythmia • Can precipitate gouty arthritis (increased uric acid) • Adverse effect on glucose and lipids (especially with B-Blockers) • Poorer compliance noted than with other classes • Very inexpensive, effective
“EVERYTHING ELSE” ALPHA BLOCKERS • End with “-azosin” • Prazosin, terazosin • Also used for enlarged prostate • Block alpha adrenalin receptors • Strong rapid blood pressure reduction • Dose must be started low and raised slowly • Side effect: • Postural hypotension (may be severe)
CONCLUSION... • HTN is most important cause of stroke, angina and renal and heart failure • Most important key for successful treatment is patient education • Important to focus on multiple CV risk factors: • 10% in BP + 10% in TC = 45% in CVD!
QUESTIONS? THANK YOU!