10 Antihypertensive drugs Flashcards
Thiazide diuretics- Names
Hydrochlorothiazide
Indapamide
Chlorthalidone
Thiazide diuretics-MoA
They increase sodium and water excretion and thus lower BP by two mechanisms related to this:
- Decrease blood volume and thereby decrease cardiac output
- With continued administration over weeks/months, they also decrease PVR, due to reduction in the sodium content of arteriolar smooth muscle cells, which decreases muscle contraction in response to vasopressor agents such as norepinephrine and angiotensin
Thiazide diuretics- Clinical use
Treatment of mild to moderate hypertension
- Hydrochlorothiazide->Initial treatment of mild to moderate HPT
- Indapamide->Como with angiotensin inhibitors to control BP to reduce risk of stroke and MI
Thiazide diuretics-Adverse effects
Hypokalemia-> cardiac arrhythmias and muscle weakness.
Elevate plasma levels of: glucose, uric acid and lipids in some pat.
Hematologic toxicity
Aggravate hepatic disease and diabetes
Compensatory increase in renin secretion(Should use angiotensin inhibitor in combo with them)
Thiazide diuretics- Interactions
- Increase serum levels of lithium->Lithium toxicity
- Hypotensive effect is decreased by NSAIDS and increased by ACE inhibitors
Thiazide diuretics- Specials
- Reduces BP by 10-15 mm Hg
- Protect against osteoporosis (decrease ca excretion)
- Cheap drugs
Loop diuretics- Clinical use
Reserved for hypertensive pt who have poor renal function and serum creatinine more than 2,3mg/dL
Potassium-sparing diuretics- Names
Amiloride
Spironolactone
Eplerenone
Triameterene
Potassium-sparing diuretics- MoA
Mild natriuretic effect, and they reduce renal potassium excretion and thereby prevent hypokalemia caused by thiazide and loop-diuretics
-Spironolactone and eplerenone are mineralocorticoid receptor antagonists
Potassium-sparing diuretics- Clinical use
- Hypertension that cannot be controlled with combo of three or more drugs
- Aldosteronism and heart failure
Potassium-sparing diuretics- Adverse effects
Hyperkalemia
Potassium-sparing diuretics- Interactions
Hyperkalemic effect is increased by ACE inhibitors and potassium supplements
Alpha blockers-Clinical use
Not used in initial treatment of HPT, but can be added to other drugs when BP is not adequately controlled
Alpha blockers- Adverse effects
- Reflex tachycardia and contractile force (may increase myocardial oxygen demand)
- Fluid retention and orthostatic hypotension
Alpha blockers- interaction
Hypotensive effect is increased by beta blockers and diuretics
Beta blockers- Clinical use
Hypertensive pt with cardiovascular diseases such as CAD, MI and heart failure
Beta blockers- Adverse effects
- Bronchospasm (avoid in COPD or use selective)
- Hypoglycemia in excessive insulin administration and blockade of early signs of hypoglycemia (caution in pt with diabetes)
- Decreased peripheral blood flow during exercise and risk of cold extremities
Beta blockers- Interactions
Hypotensive effect is decreased by NSAIDS
Centrally acting drugs- Names
Clonidine
Guanfacine
Methyldopa
Centrally acting drugs-MoA
Activates a2 receptors in brainstem and decrease sympathetic outflow, and vascular resistance
Centrally acting drugs-Clinical use
Clonidine->Hypertensive urgencies and decrease withdrawal symptoms
Methyldopa-> Hypertension in pregnant women
Centrally acting drugs-Adverse effects
Sedation, dry mouth, impaired mental acuity and rebound hypertension (if drug is discontinued abruptly)
-Methyldopa->Immunologic effects (Coombs positive hemolytic anemia and autoimmune hepatitis)
Centrally acting drugs-Interactions
-Hypotensive effect decreased by TCA
-Sedative effect increased by CNS depressants
Methyldopa->Hypotensive effect increased by levodopa
ACE inhibitors- names
Benazepril Enalapril Quinepril Ramipril Fosinepril Lisinopril Captopril
ACE inhibitors- MoA
They inhibit angiotensin-converting enzyme and thus the production of angiotensin II. This leads to several effects;
- Decreased vasoconstriction and thus decreased vascular resistance both in arteries (decreased afterload), and veins (decreased preload).
- Reduce aldosterone secretion, sodium and water resorption, norepinephrine release and leads to potassium retention.
- Inhibits inactivation of bradykinin by ACE and thus vasodilation
ACE inhibitors- Clinical use
Hypertension in Heart failure, MI, CKD, and DM patients
ACE inhibitors. Adverse effects
Fetal injury and death, renal failure in pt with bilateral renal artery stenosis, dry cough, angio edema, rash and abnormal taste
ACE inhibitors- Contraindication
Pregnancy
ACE inhibitors- Interactions
- Antihypertensive effect is increased by diuretics and CCBs
- Lithium toxicity
- Hyperkalemic effect is increased by PS-diuretics and potassium supplements
- Hypotensive effect is decreased by NSAIDs
ACE inhibitors-Specials
- All except captopril and lisinopril are prodrugs
- Enalaprilat is available IV, the rest is taken orally
Angiotensin receptor blockers-Names
Valsartan irbesartan Losartan Telmisartan Candesartan
Angiotensin receptor blockers-MoA
These drugs selectively block AT1 receptors in various tissues and thereby reduce vasoconstriction, aldosterone secretion, sodium reabsorption by the proximal tubule and norepinephrine release from sympathetic nerve terminals.
Angiotensin receptor blockers-Clinical use
Hypertension (reduce cardiovascular consequences including, LVH and stroke)
Angiotensin receptor blockers-Adverse effects
Hyperkalemia, neutropenia, elevated aminotransferases, and fetal injury
Angiotensin receptor blockers-Contraindication
Pregnancy
Direct renin inhibitor name and clinical use
- Aliskiren
- Hypertension
Calcium channel blockers-Name
Diltiazem verapamil amlodipine felodipine isradipine nicardipine nifedipine
Calcium channel blockers-MoA
By blocking calcium ion channels in the plasma membranes of smooth muscle, the ccbs relax vascular smooth muscle and causes vasodilation. They have greater effect on arteriolar smooth muscle then venous, effect on BP is mainly because a reduction in PVR.
Calcium channel blockers-Clinical use
Hypertension, angina pectoris, peripheral vascular disorders, cardiac arrhythmias
- Hypertension pt with asthma
- Protect against stroke, CAD and kidney disease
Calcium channel blockers-Adverse effects
Dihydropyridine drugs may cause reflex tachycardia and gingival hyperplasia
Hydralazine and minoxidil- MoA and clinical use
- Vasodilator
- Hypertension and alopecia
Hydralazine and minoxidil- Adverse effects
When used alone->Reflex tachycardia, fluid retention, and precipitation of angina in susceptible pt (Combine with diuretic + beta blocker or sympatholytic agent)
- Hydralazine-> Lupus like syndrome
- Minoxidil->Hypertrichosis
Nitroprusside- Moa and clinical use
- Vasodilator
- Management of hypertensive emergencies
Fenoldopam- Moa, clinical use and adverse effects
- Dopamine D1 agonist that leads to vasodilation in coronary, renal and mesenteric vessels
- Hypertensive emergencies
- Reduce potassium levels in blood
