Pharmacotherapy of HTN Flashcards
Epidemiology of HTN
1/3 adults in US have HTN
About 70% of people with MI, CVA, or heart failure have BP >140/90
Normal BP
<120/80
Pre-HTN
120-139/80-89
Stage 1 HTN
140-159/90-99
Stage 2 HTN
>160/100
CVD risk doubles with what increase in BP?
20/10
Evaluation of elevated BP
- Asses lifestyle and identify other CV RFs or concomitant disorders
- Reveal identifiable causes of high BP (primary vs secondary HTN)
- Asses the presence or absence of target organ damage
JNC 7 Major Cardiovascular Disease RFs
HTN
Tobacco Use
Obesity
Physical inactivity
DM
Dyslipidemia
Microalbuminuria
Age (55/65)
FHx of premature CVD (MI/sudden death)– 55/65
Definable causes of HTN
(secondary HTN)
Sleep apnea
Chronic kidney disease
Primary aldosteronism
Renovascular disease
Chronic steroid therapy/Cushings syndrome
Pheochromocytoma
Coarctation of the aorta
Thyroid or parathyroid disease
Medications that can cause HTN
NSAIDs
Corticosteroids
Oral contraceptives
Cocaine, amphetamines
Sympathomimetics
Erythropoieten
Licorice
Target Organ Damage
Heart: LV hypertrophy, angina or prior MI, prior coronary revascularization, heart failure
Brain: stroke/TIA
Nephropathy
Peripheral artery disease
Retinopathy
Goal of HTN therapy
Reduce CVD and renal morbidity and mortality
Achieve SBP goal
Blood pressure goals for uncomplicated HTN
<140/90
Blood pressure goals if also have DM, renal disease, CAD, CAD equivalents, Framingham score >10%, or left ventricular heart failure
<130/80
The Big 5: Lifestyle Modifications to Manage HTN
- Weight reduction
- DASH diet
- Decrease Sodium intake
- Physical activity
- Moderation of alcohol consumption
Pharm treatment decreases the risk of what?
clearly decreases the incidence of cardiovascular morbidity and mortality
Dec BP by 5-6 leads to 42% dec in stroke and 14% in CHD
Potential additive favorable and unfavorable effects of thiazide diuretics
Useful in slowing osteoporosis
Should be used cautiously with history of gout or hyponatremia
Potential additive favorable and unfavorable effects of BBs
Useful in treating atrial tachyarrhythmias/fib, migraine, essential tremor, perioperative HTN
Avoid in pts with asthma, reactive airways disease, or second/third degree heart block
Potential additive favorable and unfavorable effects of CCBs
Useful in Raynuad’s syndrome and certain arrhythmias
Potential additive unfavorable effects of ACEI
Do not use in women who are pregnant or may become pregnant
Do not use if hx of angioedema
Preferred Combos of synergistic antihypertensives
ACEI + thiazide
ACEI + DHP CCB
ARB + thiazide
ARB + DHP CCB
NOT preferred combos of antihypertensives
ACEI + ARB
BB + ACEI or ARB
BB + NDHP CCB
BB + Central acting
Follow up in pts being treated for HTN
Patients should return of f/u and adjustment of meds until goal is reached:
- Check BP 2-4 weeks after start or change in dose, assess response after 4-6wks
- More frequent visits for stage 2 or if comorbid conditions
After BP at goal, f/u at 3-6 month intervals
Serum potassium and creatinine montitored 1-2times/year
May come in more frequently if other comorbid conditions
Monitoring of pts being treated for HTN
- Diuretics
- Aldosterone antagonists
- ACEI
- ARBs
- CCB
- BB
Diuretics
- K, Mg, UA, Cr, Na, BG
Aldosterone antagonists, ACEI, ARBs
- Cr, K
CCB, BB
- HR
Antihypertensive Therapy Adherence Issues
One in four will take taking med withing 6 months. To improve this:
- Educate pts why its import to control BP
- Identify problems with drug tolerance as early as possible
- Address increased urination with diuretics; use low doses and advise that limiting salt will help decrease urination and improve thiazide efficiency
- Use generics or combo products to dec cost
If patient is not responding to treatment, check causes of resistant HTN
Improper BP measurement
Volume overload
- Excessive sodium intake
- Volume retention from kidney disease
- Inadequate diuretic therapy
Medication
- Nonadherence
- Inadequate doses
- Drug interactoins
Associated conditions
- Obesity, excess EtOH intake
- Secondary HTN
HTN Urgency
DBP > 130mmHg but no target organ damage
Can use oral agents
Reduce DBP to 100 mmHg within 24hrs
HTN Emergency
DBP > 130mmHg and target organ damage present
Goal: reduce DBP to 110mmHg in 30 minutes, then to 100 within 12-24 hrs
Requies IV drug therapy: nitropusside, nicardipine, fenoldopam, nitroglycerin, enaliprilat, hydralazine, diazoxide
What is the inital drug of choice for most patients, either alone or in combination?
Thiazide diuretics
Classes of diuretics
Thiazides
Potassium sparing
Loop
Thiazide Diuretics
Chorthalidone (Thalidone)
Work at distal tubule to
- Inc Na excresion
- Dec plasma volume and CO
Adverse Effects
- Hypokalemia and hypomagnesemia
- Hyperuricemia
- Hyperglycemia
Effective in renal insufficiency, unless really severe (SCr)
**Potassium Sparing Diuretics **
Spironolactone
Weak diuretic effects at collecting duct
Used with thiazides because will offset hypokalemia by conserving potassium
If used with ACEI may cause hyperkalemia
May cause gynecomastia because aldosterone antagonist
**Loop Diuretics **
Furosemide
More potent diuretic effect at loop of Henle to
- Inc Na excretion
- Dec plasma volume
More effective than thiazide in pts with significant heart failure or renal insufficiency
Greater risk for hypokalemia, hypomagnesemia, overdiuresis, and metabolic alkalosis
**ACE Inhibitors **
Lisinopril (Prinivil, Zestril)
Mechanism of Action
- By inhibiting ACE, they…
- Block formation of Angiotensin II (powerful vasoconstrictor)
- Dec Aldosterone (dec Na retention)
- Inc Bradykinin (vasodilator)
May cause hyperkalemia (especially with potassium sparing diuretic). Consider stopping diuretic to avoid excessive hypotension.
Adverse effects:
- cough, hypotension, rash, angioedema, and acute renal failure in pts with bilateral renal artery stenosis
- Do not use in pregnant women
Angiotensin II Receptor Blockers (ARB)
Losartan
By blocking the angiotensin II receptor, they
- cause vasodilation
- Dec aldosterone (dec Na retention)
Adverse effects: Same as ACEI, except no cough or rash (hypotension, angioedema, acute renal failure)
Use in pts who cannot tolerate ACEI
**Direct Renin Inhibitors **
Aliskiren
By directly inhibiting renin, they lead to
- Vasodilation
- Dec aldosterone (dec Na retention)
Adverse effects:
- Diarrhea
- Cough, angioedema
- Do not use in pregnancy
ESPENSIVE
**Calcium Channel Blockers **
Class effects
Block intracellular influx of calcium therby causing vascular smooth muscle relaxation or vasodilation
Adverse side effects:
- headache
- dizziness
- peripheral (ankle) edema
- eczema in elderly
- Do not use in pts with HF because dec’s contractile force of heart
Calcium Channel Blockers–Dihydropyridine class
**Amlodipine **
Contractility (-)
Peripheral Vasodilation (+++) Strong
May cause tachycardia–because heart compensating for fluid accumulating in LE
Calcium Channel Blockers–Non-dihydropyridine Class
Diltiazem and Verapamil
Diltiazem
- Contractility (- -)
- Peripheral Vasodilation (++)
Verapamil
- Contractility (- - -)
- Peripheral Vasodilation (++)
- May increase digoxin levels significantly,
- May cause constipation
Both slow down HR, so use caution in pts with bradycardia, heart block, or sinus node disease
**Beta Blockers **
Class adverse effects and comments
Beta 2 blockade may aggrave asthma
CI in patients with bradycardia, heart block, and sinus node disease due to decreased HR
Caution use in pts with uncontrolled HF
May cause:
- fatigue
- bradycardia
- aggrevate PVD
- masks signs of hypoglycemia
- insomnia, nightmares
Do not stop abruptly in pts with IHD
Beta Blockers Classes and MOA
Non-Selective (Propranolol)
Cardioselective (Atenolol, Metoprolol)
Mixed alpha-beta (Labetalol)
Intrinsic Sympathomimetic Activity (ISA) (Acebutolol)
Non-Selective (Propranolol)–beta 1 and 2
- Block beta 1 in heart to…
- Dec HR and CO, therefore dec BP
- Also dec plasma renin activity
Cardioselective (Atenolol, Metoprolol)
- Same as non-selective
Mixed alpha-beta (Labetalol)
- Same as beta blocker with additional alpha blocking effects (vasodilation)
Intrinsic Sympathomimetic Activity (ISA) (Acebutolol)
- Same, but only indicated for HTN
- Does not confer cardioprotective effects
Second line agents for HTN
Centrally Acting alpha-2 Agonists
Peripherally-acting Adrenergic Antagonists
Direct Vasodilators
alpha-1 Receptor Blockers
