Anti-hypertensive drugs Flashcards
What are some sequelae of hypertension?
MI
Congestive HF
Renal damage
Cerebrovascular incidents
Hypertensive encephalopathy
Aneurysm (thoracic or abdominal)
Aortic dissection
What are the major factors influencing blood pressure?
Cardiac output & peripheral resistance
What affects cardiac output and peripheral resistance?
Cardiac output: heart rate, contractility and filling pressure which is determined by venous tone and blood volume
Peripheral resistance: arteriolar tone
What are the two kinds of angiotensin inhibitors?
ACE-I inhibitors and AT-1 blockers
What are some examples of ACE-I inhibitors?
Lisinopril, captopril, enalapril (basically all the prils)
What is the action of ACE-I inhibitors?
Prevents the conversion of angiotensin I to angiotensin II
What are the clinical uses of ACE-I inhibitors?
Hypertension
Cardiac failure
Post-MI
Renal insufficiency
what are the adverse effects of ACE-I inhibitors?
- Severe hypotension
- Renal failure
- Hyperkalemia due to decreased K+ secretion
- Angioedema and dry cough due to increased bradykinin and substance P activity (ACE breaks them down!)
Contraindicated in pregnancy! (teratogenic among other things)
What are the sartans? losartan, valsartan etc
Angiotensin II type I (AT1) blockers
what is the action and adverse effects of AT1 blockers?
they block the receptors, preventing the action of angiotensin II at AT1 receptors
also contraindicated in pregnancy but have less/no dry cough
What is the MOA of beta blockers?
B1 blockade inhibits adenyl cyclase which ultimately inhibits the opening of calcium channels and decreases contractility
they prevent calcium induced calcium release as well
B2 inhibition also causes bronchoconstriction by decreasing cAMP formation and thus reducing the amount of inactivated MLCK – reducing bronchodilation and thus causing bronchoconstriction
What are some non-selective beta-blockers?
Propanolol
Pindolol
Carvedilol
What are some B1 selective beta-blockers?
BAM
Bisoprolol
Atenolol
Metoprolol XL (normal metoprolol doesn’t work for HF)
What is a mixed/3rd gen beta blocker?
What does being mixed entail?
Nebivolol
- B1 selective in low doses or in people who have fast metabolism
- non-selective in high doses or people w slow metabs
- also has vasodilatory effects through increased NO release
What are the clinical uses of beta blockers?
Hypertension
Heart failure
Abnormal heart rhythms
Post MI
Anxiety
What are the adverse effects of beta blockers?
Hypotension
Bradycardia
Reduces exercise capacity
AV nodal block
Too much bronchoconstriction (in asthmatics, for e.g.)
CNS effects: vivid dreams, beta blocker blues (clinical depression)
how is calcium reabsorbed in the kidneys?
it is reabsorbed by epithelial cells in the distal convoluted tubule
- via an apical Ca2+ channel and a basolateral Na+/Ca2+ exchanger
What are some examples of thiazides?
Hydrochlorothiazide and indapamide
What is the MOA of thiazides?
Basically diuretics
They inhibit NaCl reabsorption by blocking the Na/Cl transporter – this increases excretion of salt and thus water – thus anti hypertensive
They also enhance Ca2+ reabsorption in the distal convoluted tubule
Impt to note that PGs synthesized by the kidney are somehow needed for thiazides to work. Therefore NSAIDs can interfere with thiazides
What are the clinical uses of thiazides?
- Hypertension
- Congestive heart failure
- Nephrolithiasis due to idiopathic hypercalciuria
- Nephrogenic diabetes insipidus
What are the adverse effects of thiazides?
- Hypokalemic metabolic alkalosis
- Hyponatremia
- Hypercalcemia
- Hyperuricemia
- Hyperglycemia
- Hyperlipidemia
