HTN Flashcards
What is the lifetime risk of developing HTN?
90%
What is the prevalence of HTN in adult?
1 in 3
HTN is a risk factor for developing what?
Heart disease
Stroke
Heart failure
Renal disease
What are some of the pathophysiologic mechanisms behind HTN?
Sex, Environment (stress), Genetics, CNS (sympathetic), Cardiac (CO), Renal (Na+ retention), G.I (obesity, nutrients, alcohol), Endocrine (insulin, aldosterone), Age, Endothelium (NO, endothelin)
List risk factors for HTN
Cigarette smoking Obesity ( BMI > 30) Physical inactivity Dyslipidemia DM Renal dysfunction (may also be an end result) Age: MEN > 55, WOMEN > 65 Family h/o premature CVD: men < 55, women < 65
Differentiate between Essential & Secondary HTN
Essential accounts for 90% of cases; has a hereditary component
Secondary accounts for < 10%; common causes are chronic kidney dz, renovascular dz, pregnancy, medications, etc.
Differentiate between Systolic & Diastolic BP
Systolic: represents cardiac contraction
Diastolic: represents nadir, filling of the heart
Define Cardiac Output (CO) and Total Peripheral Resistance (TPR)
CO: AMOUNT of blood pumped out by the ventricles (represents SBP)
TPR: sum of peripheral resistance in peripheral vasculature (represents DBP)
How would you calculate BP if given CO & TPR
BP = CO x TPR
What is the mechanism behind increasing peripheral resistance?
Functional Vascular Constriction/ Structural Vascular Hypertrophy (narrows the vessel as well)
- -> overactivity of sympathetic NS
- -> Genetic components
What is the mechanism behind increased CO?
Increased preload
–> increased fluid volume
–> excess Na+ intake
–> renal Na+ retention
water follows Na+
What are possible mechanisms behind venous constriction?
- ->Excess RAAS stimulation (constriction = more H2O, Na+ = increased BP)
- -> Sympathetic NS overactivity
What are the new JNC 8 goals for BP?
- Pts > 60
- Pts < 60
- Pts w/ DM and CKD
- Pts w/ DM (per ADA)
- Pts > 60 goal: < 150/90
- Pts < 60 goal: < 140/90
- Pts w/ DM & CKD goal: < 140/90
- Pts w/ DM (per ADA) goal: <140/ 80
What are some of the lifestyle modifications suggested to lower BP?
Smoking cessation
Weight loss (overweight/ obese pts)
DASH diet (fruits, veggies, whole grains)
Dietary Sodium restriction
Increased physical activity
Limit alcohol intake to < 1-2 drinks/ day
What is the most effective lifestyle modification used to lower BP? By how much?
Recommendations?
Losing weight: could reduce systolic BP by 5-20 mm Hg PER 10- kg wt loss
Recommendation is to maintain a BMI between 18.5-24.9
What is a DASH diet pattern? How does it affect BP?
A diet rich in fruits, veggies & low-fat dairy products with reduced saturated & total fat
May reduce systolic BP 8-14 mmHg
What is the ideal Sodium intake for a pt with HTN?
Ideally, 65 mmol/day (1.5g/ day sodium or 3.8g/day NaCl)
What are the four first line options for treating HTN?
Thiazides, Calcium Channel Blockers (CCBs), ACE-Inhibitors, ARBs (Angiotensin II receptor blocker)
Which two medication classes should not be used in African American pts to treat HTN?
ACE-I & ARBs
1st line would be a Thiazide or CCB
Which two medication classes are recommended for treating HTN in a pt with DM or CKD?
ACE-I & ARBs: DO NOT USE THEM TOGETHER!
Which medication class should be used to treat HTN in a pt with a cardiac history (i.e. M.I., CHF)?
Beta-Blockers
What is the 1st option in the treatment approach to HTN?
Start with 1 DRUG and MAX THE DOSE; then add on 2nd agent if not at goal and MAX THE DOSE PRN; add on a 3rd agent if still not at goal –> referral to specialist if still not at goal after 3rd drug
What is the 2nd option in the treatment approach to HTN?
Start with 1 DRUG, and ADD 2ND DRUG if not at goal (prior to maxing out 1st drug); MAX THE DOSE ON BOTH DRUGS; if not at goal, add 3rd agent
What is the 3rd option in the treatment approach to HTN?
Start with 2 DRUGS from the beginning IF SBP > 160 and/or DBP > 100; MAX OUT BOTH DRUG DOSES; if not at goal, add 3rd agent
Give examples of the 3 Thiazide Diuretics, what is the MOA?
- Hydrochlorothiazide (HCTZ), chlorthalidone, metolazone
- Inhibits Na+ reabsorption in the DISTAL TUBULE (better at lower BP than regular diuretics
Which is the most common Thiazide diuretics? Least common?
HCTZ = MC
Metolazone is rarely used; potent diuretic
What is the place in therapy for a Thiazide diuretic? What is the typical dose?
One of the FIRST LINE drug classes in treating HTN
25mg (can start at 12.5 mg); any dose >25 mg will NOT be more effective, may show more ADEs
What are some adverse effects of Thiazide diuretics?
- Orthostatic hypotension;
- Electrolyte abnormalities (DECREASED K+, Na+; INCREASED Ca++, uric acid, glucose) –> avoid with gout or kidney dz;
- Photosensitivity (recommend SPF >30)
- Increase in urination (initially) –> TAKE IN THE AM
What precautions should you adhere to when prescribing Thiazide diuretics?
-Use caution in pts with SULFA ALLERGY (anaphylactic)
-INEFFECTIVE IN PTS WITH SEVERE RENAL DZ: CrCl
< 30 mL/min – won’t even get into DCT to work
-AVOID in pts taking Lithium (may increase [Lithium] d/t similar structure)
Give examples of Loop Diuretics
What is the MOA?
Furosemide (Lasix), Bumetanide, Torsemide
- Inhibits active transport of Na+, Cl- & K+ in thick ASCENDING LIMB of Loop of Henle –> ion excretion
- Collecting duct EXCRETES MORE H2O in response
What is the most potent of the loop diuretics? The least? Give equivalence doses
MOST –> Torsemide (1 mg) = Bumetanide (20 mg) = Furosemide (40 mg) <– LEAST
What is the place in therapy of Loop Diuretics?
- CHF (preferred)
- Edema (both peripheral & pulmonary)
- HTN (not 1st line)
What are some adverse effects of Loop Diuretics?
Precautions?
- Electrolyte abnormalities (DECREASED: K+, Na+, Ca++, Mg; INCREASED: uric acid –> gout!!)
- Dehydration
- Ototoxicity (esp if combined w/ another agent)
- Increase in SCr
- Caution in sulfa-allergic pts
- Nephrotoxicity
What are the two subcategories of Potassium-Sparing Diuretics?
Aldosterone Receptor Blockers
Potassium Sparing Drugs