Drugs Used to Treat HTN Flashcards
Why is chlorthalidone a preferred thiazide diuretic?
–prolonged half-life (50hrs)
Is chlorthalidone a K+ sparing or a K+ losing diuretic?
K+ losing, b/c it acts in the distal tubule which is upstream from the Na+/K+ ATP-ase in the collecting duct
What is the mechanism of action of chlorthalidone?
–blocks the Na+/Cl- cotransporter in the distal tubule, (thus inhibiting Na+ reabsorption back into the body)
What is the mechanism of action of amiloride and triamterene?
-blocks ENaC
Are triamterene and amiloride K+ sparing or K+ losing diuretics?
K+ sparing
-thus can be considered for use in pt’s w/ hypokalemia who are on thiazide monotherapy
Can you use K+ sparing diuretics in pt’s with kidney disease?
No, do NOT use in pt’s with a GFR < 45 mL/min
What is the mechanism of action of HCTZ?
-blocks Na+/Cl- cotransporter in the DCT
Is HCTZ K+ losing or K+ sparing?
K+ losing, because it works upstream from the Na+/K+ pump in the collecting duct
Can HCTZ be used in pt’s with a low GFR?
No
What is a use for HCTZ in regards to calcium?
-Tx of calcium nephrolithiasis
- -d/t calcium being actively reabsorbed from the DCT
- -thus, it may cause hypercalcemia
What are some side effects of HCTZ?
- hypokalemia
- hypomagnesemia
- hyponatremia
- hypochloremic metabolic alkalosis
Is HCTZ a sulfa drug?
Yes
What is metolazone?
-a thiazide diuretic that is a cardiologist’s favorite for use as an adjunct diuretic in the Tx of CHF
What is the mechanism of furosemide (a loop diuretic)?
blocks the Na+/K+/2Cl- cotransporter in the Loop of Henle
What are the indications for using furosemide (a loop diuretic)?
- edema associated w/ heart failure
- HTN
-Tx for acute pulmonary edema by decreasing preload
(rapid relief of dyspnea)
Does furosemide work in patients with a low GFR?
Yes (unlike thiazides)
What are side effects of furosemide?
- hypokalemia and hyponatremia
- hypochloremic metabolic alkalosis
- hypocalcemia (increased risk of kidney stones)
- hyperglycemia
- hyperuricemia
- ototoxicity
What loop diuretic can be used in pt’s with a sulfa allergy?
-ethacrynic acid
What is the class and mechanism of action of captopril?
- ACEi
- competitive inhibitor of ACE
What are the advantages of benazepril and lisinopril over captopril?
longer half-life, which allows 1x daily dosing
What are the two major side effects of ACEi’s?
- cough
- angioedema
In treating blacks w/ HTN, what class of drugs should be included in the initial treatment?
-thiazide or CCB
What are some medications that are safe during pregnancy?
- methyldopa
- nifedipine
- labetalol
-do NOT treat w/ ACEi’s, ARB’s, or aliskiren
