Treating Hypertension Flashcards
A single elevated blood pressure reading . . .
. . . does not establish a diagnosis of HTN
Nonpharmacologic treatments for HTN
- Weight Loss
- Exercise
- Diet (lower sodium intake, increase potassium intake, decrease alcohol consumption)
- Smoking cessation
- Relaxation therapy
Pharmacologic management of blood pressure tree diagram
___ are the most commonly perscribed diuretics.
Thiazides are the most commonly perscribed diuretics.
Adverse thiazide side effects
- Increased blood glucose, TAG, and LDL
- Hypokalemia
- Hyperuricemia
- Decreased sexual function
Doxazosin
α1-antagonist
ACE inhibitor mechanisms
- Decreased angiotensin II direct vasoconstriction
- Decreased sodium and water retention
- Increased circulating bradykinin (vasodilation)
ACE inhibitor side effects
- Dry cough
- Hyperkalemia
- Azotemia (high levels of nitrogen-containing metabolites)
Angiotensin II receptor blockers
Inhibit vasoconstriction and aldosterone selection by directly antagonizing the AT1 receptors. Usually much better tolerated than ACE inhibitors, and do not have cough as a side effect.
Current recommendations for limiting salt intake in hypertensive patients
<6 g of sodium chloride per day
This is less than 1/3 the average American’s daily salt consumption
Centrally acting α2-adrenergic agonists
Ex, methyldopa and clonidine
Reduce sympathetic outflow to the heart, blood vessels, and kidneys
Rarely used owing to their high frequency of side effects (e.g., dry mouth, sedation)
Direct renin inhibitor
Aliskiren
Newest class of antihypertensives. reduces levels of angiotensin I and angiotensin II by binding to the proteolytic site of renin, thus inhibiting cleavage of angiotensinogen.
Side effects and long-term effects still unknown.
Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure recommendations for treating HTN
- Start with thiazide diurectics as the first line treatment for uncomplicated HTN
- In patients with concurrent heart failure, diabetes, or LV dysfunction following myocardial infarction, consider starting with an ACE inhibitor
- In a patient with CAD, a β-blocker is most appropriate
Why is combination drug therapy so frequent in treating HTN?
The effects of one drug, acting at one physiologic control point, can be defeated by natural compensatory mechanisms.
For example, the drop in renal perfusion by a direct vasodilator can activate the renin–angiotensin system, prompting the kidney to retain more volume, thereby blunting the antihypertensive benefit. A direct vasodilator is often paired with a low-dose diuretic to avoid the undesired volume expansion effect.
Effects of pregnancy on blood pressure
BP usually declines during the first trimester of pregnancy and then slowly rises.
Preeclampsia
A dangerous form of hypertension with proteinuria that has the potential to result in serious adverse consequences for a pregnant mother (stroke, HF) and fetus (small for gestational age, premature birth)
Most effective risk reduction is with beta blockers and calcium channel blockers.
Many commonly used antihypertensives, such as ___, are contraindicated for pregnancy
Many commonly used antihypertensives, such as ACE inhibitors, angiotensin receptor blockers, and direct renin inhibitors, are contraindicated for pregnancy
What drugs are indicated for treatment of hypertensive pregnant women?
- Beta blockers (labetalol)
- Calcium channel blockers (nifedipine)
- Centrally acting alpha2 agonists (methyldopa)
- Alpha1 blockers (hydralazine)
Factoring racial trends into treating blood pressure
In general, whites appear to respond better to beta-blockers and ACE inhibitors whereas blacks appear to respond better to diuretics and calcium channel blockers.
You should know these, BUT, do not let them guide clinical decisions. HTN is a patient-tailored approach and this is a sweeping generalization that is not particularly nuanced.
Most hypertensive patients need ____ for adequate blood pressure control
Most hypertensive patients need 2 to 4 drugs for adequate blood pressure control
Thiazides: Mechanism, When to use, Side effects
Hydrochlorothiazide and Chlorthalidone
Mechanism: Blocks Na+ and H2O reabsorption at distal convoluted tubule
When to use: 1st line anti-HTN medication, Can use with loop diuretics to increase diuresis in volume overload
Side effects: HYPOKALEMIA, Volume depletion, Metabolic alkalosis, Hypercalcemia, Hyperuricemia/Gout
Loop diuretics: Mechanism, When to use, Side effects
Furosemide and Torsemide
Mechanism: Blocks Na+ and H2O reabsorption at ascending loop of Henle
When to use: Congestive heart failure, Edema/volume overload, hyperkalemia
Side effects: HYPOKALEMIA, Volume depletion, Metabolic alkalosis, Ototoxicity
K+ sparing diuretics: Mechanism, When to use, Side effects
Spironolactone
Mechanism: Mineralocorticoid receptor blocker, indirectly blocks Na+ and H2O reabsorption at collecting duct
When to use: Management of refractory edema in CHF and cirrhosis, Reduction of K+ loss from other diuretic therapy, Attenuation of cardiac remodeling in heart failure
Side effects: HYPERKALEMIA, Gynecomastia
