Antihypertensives Flashcards
What is considered stage I vs. stage II HTN?
- stage I: 130-139/81-89
- stage II: ≥140/90
What are the 8 classes of antihypertensive drugs currently used in the treatment of HTN?
- Diuretics
- ACE inhibitors
- ARBs
- CCBs
- BBs
- Centrally-acting agents
- Alpha adrenergic blockers
- Vasodilators
Which drugs are the first line drugs of choice for treatment of HTN?
- Diuretics
- ACEIs
- ARBs
- CCBs
What are compelling indications for diuretics?
- first-line choice for uncomplicated HTN
- effective for mild/moderate HTN combined w/ lifestyle modifications
- more effective in AAs than ACEIs or ARBs
What are the main adverse effects associated with the thiazides?
- hypokalemia
- hyperuricemia (uric acid is reabsorbed at the PT, and diuretics compete with transport of uric acid back into the lumen at the DT)
What are the tricks to avoid hypokalemia associated with thiazide diuretics?
- decrease dose
- decrease Na+ intake
- increase K+ intake
- combine w/ BBs, ACEIs, or ARBs
What is a contraindication and relative contraindication for thiazides?
- contraindication=hypokalemia
- relative contraindication=pregnancy
Why can thiazide diuretics cause hyperglycemia?
due to K+ loss (K+ normally stimulates insulin release)
How do beta blockers interact with thiazides?
Beta blockers have an effect on glucose (contribute to hyperglycemia). Thiazides can also result in hyperglycemia. This creates a situation of prolonged hyperglycemia, which is dangerous.
Why do the loop diuretics cause such pronounced natriuresis/diuresis?
They block the Na+/K+/Cl- cotransporter, which is responsible for reabsorbing ~50% of the Na+ filtered into the nephron.
What are the major side effects associated with the loop diuretics?
- hypokalemia
- impaired diabetes control (due to hyperkalemia)
- increased LDL/HDL
- ototoxicity (reversible)
- dehydration/hyponatremia
Describe how NSAIDs interact with the loop diuretics.
NSAIDs inhibit prostaglandins, and loop diuretics cause venous dilation via prostaglandins.
Why are the aminoglycosides contraindicated for patients on loop diuretics?
AGs may further exacerbate ototoxicity.
Which drugs are the ENaC blocker K+ sparing diuretics?
triamterene and amiloride
Which drugs are the Aldosterone Receptor Antagonists?
spironolactone and eplerenone
What makes ACE inhibitors such an effective class of drugs?
They block the action of ACE on (1) activating ang II and (2) inactivating bradykinin. No Ang II=less vasoconstriction and less aldosterone. No bradykinin breakdown=more vasodilation.
What are the 2 types of K+ sparing diuretics?
- ENaC blockers: triamterene, amiloride
- Aldosterone Receptor Antagonists: spironolactone, aplerenone
What are the side effects of K+ sparing diuretics?
- hyperkalemia (thus, don NOT use in patients who are on drugs that block RAAS)
- gynecomastia (spironolactone)
Can K+ sparing diuretics be used as monotherapy in HTN patients?
No, they must be combined with other diuretics.
What are the major contraindications for K+ sparing diuretics?
- RAS inhibitors (can add thiazide to counteract hyperkalemia)
- Addison’s disease (decreased aldosterone production)
Which is the most prescribed ACE inhibitor (and the one we should focus on)?
Lisinopril
What are the adverse effects of ACE inhibitors?
- dry cough
- hyperkalemia
- angioedema (rare, can be life-threatening)
- rash
True or false: K+ sparing diuretics combined with ACE inhibitors serves as a good combination for treatment of HTN.
FALSE! K+ drugs used with ACE inhibitors will exacerbate hyperkalemia.
What are the benefits of lisinopril over captopril or enalapril?
Lisinopril is excreted unchanged by the kidney, has a longer HL (allowing for once daily dosing), and has a more predictable onset/duration of action.