Hypertension Flashcards
Pre-Hypertension
Classification and management
- systolic bp 120-139 mm Hg
- diastolic bp 80-89 mm Hg
- without compelling indication - no drug therapy indicated
- with compelling indication - drugs for compelling indication
Stage 1 HTN
Classification and management
- SBP - 140 - 159 mm Hg
- DBP - 90 - 99 mm Hg
- without compelling indication - thiazide-type diuretic, ACEI, ARB, DHP-CCB
- with compelling indication - drugs for compelling indications. other antihypertensives as needed
Stage 2 HTN
Classification and management
- SBP of 160 mm Hg or greater
- DBP of 100 mm HG or greater
- Without compelling indication: two drug combination for most (usually thiazide-like diuretic and ACEI, ARB or DHP-CCB)
- with compelling indication - drugs for compelling indications. Other antihypertensives as needed
Identifiable causes of HTN
- sleep apnea
- drug induced or related causes
- CKD
- primary aldosteronism
- renovascular disease
- chronic steroid therapy or Cushings syndrome
- pheochromocytoma
- coarctation of the aorta
- thyroid or parathyroid disease
Risks of HTN
- pts 40 -70 years each increment of 20mmHg SBP or 10mmHg DBP doubles the risk of CVD across the range of 115/75 - 185/115 mmHg
- Target organ damage:
- heart
- left ventricular hypertophy
- angina or MI
- coronary revascularization
- heart failure (HF)
- reduced left ventricular ejection fraction
- preserved left ventricular EF
- brain - stroke or TIA
- CKD
- PAD
- Retinopathy
- heart
Benefits of Lowering BP
- Associated with the relative risk reduction in the incidence of:
- Stroke - 35-40%
- MI - 20-25%
- HF - greater than 50%
- in patients with stage 1 HTN and additional cardiac risk factors, achieving a sustained 12mm Hg over 10 years will prevent one death for ever 11 patients treated
- In the presence of CVD or other target organ damage, only nine patients would require such a BP reduction to prevent a death.
Accurate BP measurement
- seated quietly for 5 minutes with feet on floor, back supported, and arm supported at heart level
- appropriate sized cuff
- at least two measurements should be made
- clinicians should provide to patients, both verbally and in writing, their specific BP readings and goals
Self-Measurement of BP
- helpful in evaluating white-coat HTN and long-term BP monitoring
- home measurement devices should be checked regularly for accuracy
- Automatically inflating arm devices are preferred over wrist monitors or manual inflation devices for accuracy
Lifestyle modification and HTN
1) weight reduction
- can reduce SBP by 5-20 mm HG for every 10kg
2) diet
- DASH diet can reduce SBP by 8-14 mm Hg
- Na restriction can reduce SBP by 2-8 mm Hg
3) exercise
- 30 minutes of aerobic activity on most days of the week can reduce SBP by 4-9 mm HG
4) moderation of alcohol consumption
- limiting to no more than two drinks a day for men or one drink a day for women can reduce SBP by 2-4 mm Hg
ACEIs
Mechanism of action
- prevents conversion of angiotensin I to angiotensin II (potent vasoconstrictor) by competitive inhibition of ACE
- results in lower BP secondary to lower levels of angiotensin II, increased levels of plasma renin activity, and a reduction in aldosterone secretion
ACEIs
Evidence
- HOPE (Heart Outcomes Prevention Evaluation Study)
- effects of ramipril on CV events in high risk patients - EUROPA
- efficacy of perindopril in reduction of cardiovascular events among patients with stable coronary artery disease - PEACE
- ACEI in stable coronary artery disease - PROGRESS
- randomized trial of a perindopril-based BP lowering regimen among 6,105 patients with previous stroke or TIA - SAVE (Survival and Ventricular Enlargement trial)
- effect of captopril on maortality and morbidity in patients with left ventricular dysfunction after MI
ACEIs
Clinical use
- Compelling indications to use ACEIs 1st line
- DM - reduces the progression of nephropathy and alunminuria
- CKD - reduces the progression of diabetic and non diabetic renal disease
- HF or left ventricular dysfunction with LVEF <40%
- Post MI
- High CAD risk
- recurrent stoke prevention - reduces recurrence when used in combination with thiazide diuretic
- Recommended add-on therapy to thiazide diuretic
ACEIs
contraindications
- bilateral renal artery stenosis
- pregnancy
- angioedema
ACEIs
Important adverse drug reactions
- increasing Cr - limited rise as much as 30% above baseline is acceptable. This becomes the patients new baseline
- hyperkalemia
- angioedema - occurs two to four times more frequently in African Americans
- cough (dry)
ACEIs
Dosing and monitoring
- consider avoiding in women during childbearing years
- consider starting at lower-than-average dose if patient id elderly, in on concommitant diuretic therapy or has renal impairment
- Monitor Cr and K 7-10days after initiation or titration
ARBs
Mechanism of action
- selective, competitive antiotensin II receptor type 1 receptor antagonist, reducing end-organ response to angiotensin II
- results in decreased total peripheral resistance (afterload) and cardiac venous return (preload)
- reduction in BP occurs independently of the status of the renin-antiotensin system
ARBs
Evidence
- LIFE - Losartan Intervention for Endpoint reduction in hypertension study
- randomized trial against atenolol
- VALIANT
- valsartan, captopril, or both in MI complicated by HF, left ventricular dysfunction, or both
ARBs
Clinical use
- recommended as first line, but generally reserved for patients who have ACEI intolerance
- Compelling indications (typically after ACEI fail)
- HF or left ventricular systolic dysfunction with LVEF of 40% or less
- DM - reduces the progression of nephropathy and albuminuria
- CKD - reduces the progression of diabetic and non diabetic renal disease
ARBs
Contraindications
- bilateral renal artery stenosis
- pregnancy
- angioedema (ARB-induced or idiopathic)
- although ARBs may be considered alternative therapy for patients who have developed angioedema while taking an ACEI, patients have also developed angioedema with ARBs.
- extreme caution is advised when substituting an ARB in a patient who has had angioedema associated with ACEI use
- although ARBs may be considered alternative therapy for patients who have developed angioedema while taking an ACEI, patients have also developed angioedema with ARBs.
ARBs
Important adverse drug reactions
- Increasing SCr - limited rise of as much as 30% above baseline is acceptable. This becomes the patients new baseline
- hyperkalemia
- angioedema - less than with ACEIs
ARBs
Dosing and monitoring
- consider avoiding in women during childbearing years
- monitor Scr and K 7-10 days after initiation and titration
Renin inhibitor (aliskiren) Mechanism of action
- direct renin inhibition
- decreasing plasma renin activity and inhibiting the conversion of angiotensinogen to angiotensin I
Renin inhibitor (aliskiren) Evidence
- no outcomes data available for aliskiren mono therapy
- ALTITUDE - Aliskiren Trial in Type 2 Diabete Using Cardiovascular and Renal Disease Endpoints
- trial terminated early
- aliskiren added to ACEI or ARB therapy in patients with type 2 DM and renal impairment compared with placebo
- an increase in adverse events (nonfatal stroke, renal complications, hyperkalemia and hypotension)
- no apparent benefit to patients randomized to aliskiren
Renin inhibitor (aliskiren) Contraindicaitons
- pregnancy
- do not use with ARBs or ACEIs in patients with diabetes
Renin inhibitor (aliskiren) Important adverse drug reaction
- angioedema
- hyperkalemia if used concomitantly with ACEI
Renin inhibitor (aliskiren) Dosing and monitoring
- consider avoiding in women during childbearing years
- high-fat meals decrease absorption substantially
- patients with renal insufficiency were excluded from trials
Beta blockers
Mechanism of action
- selective (beta-1) or nonselective (beta1 and 2) receptor blocker results in negative inotropic and chronotropic actions
- some (pindolol and acebutolol) exhibit intrinsic sympathomimetic activity meaning they are cpable of exerting low-level agonist activity at the beta receptor while simultaneously acting as an antagonist
- cardioselective agents without intrinisic sympathomimetic activity are usually used for HTN
- Carvedilol and labetalol also have alpha1 blocking activity
Beta blockers
Evidence
ACCF/AHA guidelines since the 1980s
Beta blockers
clinical use
1) Compelling indications
- HF or left ventricular systolic dysfunction wiht LVEF <40% or less - 1st line with ACEI
- Post-MI (within first 3 yearr) = First line
- High CAD risk
- DM
2) Controversy regarding the appropriateness of using as first line agent in patients without a compelling indication.
Beta-blockers with alpha1-blocking activity are likely more effective antihypertensive agents than beta-blockers without this mechanism
Beta-blockers
Contraindications
- SA or AV node dysfunction
- decompensated HF
- severe bronchospastic disease
Beta-blockers
Important adverse drug reactions
- bradycardia
- heart block
- bronchospastic disease
- exercise intolerance, sexual dysfunction, fatique
Beta-blockers
Dosing and monitoring
- relative contraindications include significant sinus or AV note dysfunction, hypotension, decompensated HF, and severe bronchospastic lunch disease
- Monitor HR regularily
Thiazides
- hydrochlorothiazide
- chlorthalidone
- metolazone
- indapamide
Thiazides
Mechanism of action
- Acts on kidneys to reduce Na reabsorption in the distal convoluted tubule.
- by impairing Na transport in the distal convoluted tubule, natriauresis and concomitant water loss in induced
Thiazides
Evidence
- ALLJAT
- Preventnion of stroke by antihypertensive drug treatment in older people with isolated systolic HTN: Final results of the Systolic Hypertension in the Elderly Program (SHEP)
- Medical Research Council (MRC) trial of treatment of mild hypertension: Principal results
Thiazides
Clinical use
- prevents CVD complications
- option as first-line therapy for most patients wiht HTN, either alone or in combination with other classes (ACEI, ARBs, beta-blockers, CCBs)
- enhances the effect of multi-drug regimens
- affordable but often underused
Thiazides
Contraindications
anuria
Thiazides
Important adverse drug reactions
- electrolyte abnormalities (hypokalemia, hyponatremia)
- hyperuricemia
Thiazides
dosing and monitoring
- ineffective for patients with GFR less than 30 mL/minute
- monitor SCr, Na and K 7-10 days after initiation or titration
Loop diuretics
furosemide
bumetanide
torsemide
ethacrynic acid
Loop diuretics
Mechanism of action
- acts by reversibly binding to the Na, K, chloride cotransport mechanism on the luminal side of the ascending loof of Henle, thereby inhibiting the active reabsorption of these ions
Loop dirutetics
Clinical use
- HTN management for patients with HF and CKD using scheduled twice-daily dosing
Loop diuretics
Contraindications
anuria
Loop diuretics
Important adverse drug reactions
- electrolyte abnormalities (hypokalemia, hyponatremia, hypomagnesemia)
- dehydration
Loop diuretics
Dosing and monitoring
- avoid in patient with a CrCl less than 10ml/min
- monitor SCr and K 7-10 days after initiation or titration
DHP-CCBs
amlodipine
felodipine
nefidipine
nicardipine
DHP-CCBs
Mechanism of action
- act by relaxing the smooth muscle in the arterial wall, decreasing total peripheral resistance, and hence reducing BP
- in angina they increase blood flow to the heart muscle
DHP-CCBs
Evidenc
- ACCOPLISH
- Prevention ov CV efentwi the anti hypertensive regimen of amlodipine, adding perindopril as required vs atenolol, adding bedroflumethazine as required, in the Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowring Arm; a multicentre randomised controlled trial (ASCOT_BPLA)
- Outcoms in hpertensive patients at high CV risk treated with regimes based on amlodipine or amlodipine (VALUE)
- Effects of intensive BP lowering and low-dose aspirin in patients with HTN: Principal results of the Hypertension Optimal Treatment (HOT) randomized trial
DHP-CCBs
Clinical Use
- Option as first-line therapy for most patients with HTN
- Potent BP lowering
- improves anginal symptoms
DHP-CCBs
Important adverse drug reactions
- Peripheral edema
DHP-CCBs
Dosing and monitoring
- start at a low dose for elderly patients
nonDHP-CCBs
verapamil
diltiazem
nonDHP-CCBs
Mechanism of action
- acts as a potent vasodilator of coronary vessels, increasing blood flow and decreasing the HR by strong depression of AV node conduction
- also acts as a potent vasodilator of peripheral vessels, reducing peripheral resistance and afterload.
- has negative inoptropic effects
nonDHP-CCBs
Evidence
- Principal results of the Controlled Onset Verapamil Investigation of Cardiovascular End Points trial (CONVINCE)
- a calcium antagonist versus a non-calcium antagonist treatment strategy for patients with CAD: The International Verapamil-Trandopril Study: A randomized controlled trial (INVEST)
- randomized trial of effects of calcium antagonists compared with diuretics and beta-blockers on CV morbidity and mortality in HTN: The Nordic Diltiazem study (NORDIL)
nonDHP-CCBs
Clinical use
- used for HTN in patients iwht concomitant conditions (e.g. atrial fibrillation or stable angina) who would benefit from these medications
nonDHP-CCBs
Contraindications
- heart block
- Sick sinus syndrome
nonDHP-CCBs
Important drug reaction
- bradycardia
- heart block
- constipation
nonDHP-CCP
Dosing and monitoring
- potent CYP inhibitors; potentially serious drug-drug interactions
- do not use with concomitant systolic dysfunction HF (ejection fraction less than 40%)
- use with caution in patient on concomitant beta-blocker therapy
alpha-blockers
terazosin
doxaosin
prazosin
alpha-blockers
mechanism of action
- selective alpha-antagonsit that works by blocking the actions of adrenaline on smooth muscle of the blood vessel wall
alpha-blockers
Evidence
ALLHAT showed a 25% higher rate of combine CVD and a 2-fold higher rate of HF compared with the diuretic arm
alpha-blockers
Clinical use
- in general, reserved for hypertensive patient with concomitant BPH
- usually viewed as fourth- or fifth-line agent for HTN
alpha-blockers
Important adverse drug reactions
- dizziness
- orthostatic hypotension
alpha-blockers
Dosing and monitoring
- start with a very low dose
- patient should consider taking the first dose at night while in bed
- titrate slowly over time as needed
Aldosterone receptor blockers
- spironolactone
- eplerenone
Aldosterone receptor blockers
Mechanism of action
- inhibit the effect of aldosterone by competing for intracellular aldosterone receptors in the cortical collecting duct.
- this decreases the reabsorption of Ns and water while decreasing the secretion of K
Aldosterone receptor blockers
Evidence
- efficacy of low-dose spironolactone in subjects with resistant HTN
- the role of spironolactone in the treatment of patients with refractory HTN
Aldosterone receptor blockers
Clincial use
- resistant HTN
- patients with HTN and HF
Aldosterone receptor blockers
Contraindications
- Anuria
- Acute renal insufficiency
- Hyperkalemia
Aldosterone receptor blockers
Important adverse drug reactions
- hyperkalemia
- gynecomastia with spironolactone
Aldosterone receptor blockers
Dosing and monitoring
- monitor Cr and K -10 days after initiation or titration
Central alpha2-agonists
- clonidine
- methyldopa
- guanfacine
Central alpha2-agonists
Mechanism of action
- stimulates alpha2-receptors in the brain, which decreases sympathetic outflow cardiac output and peripheral vascular resistance, lowering BP and HR
Central alpha2-agonists
Clinical use
- may be useful for resistant HTN
- beneficial for hypertensive urgency
Central alpha2-agonists
Important adverse drug reactions
- dizziness and orthostatic hypotension
- drowsiness
- dry mouth
Central alpha2-agonists
Dosing and monitoring
- rebound HTN possible if withdrawn too quickly, especially if on concomitant beta-blocker (except carvedilol and loabetolol, because of unopposed alpha stimulation)
- avoid in patients with HF
Vasodilators
- hydralazine
- minoxidil
Vasodilators
Mechanism of actions
- direct-acting smooth muscle relaxant that acts as a vasodilator primarily in arteries and arterioles
Vasodilators
Clinical use
- may be useful for resistant HTN
- may be beneficial for patients with HTN and HF (hydrazine)
Vasodilators
Important adverse drug reactions
Hydralazine - tachycardia (use with beta-blocker) - drug-induced lupus-like syndrome Minoxidil - fluid retention (use with diuretic) - paricardial effusion - hirsutism
Vasodilators
Dosing and monitoring
- can dose two to four times daily
Achieving BP control
- most patients who are hypertensive will require two or more antihypertensive medications to achieve their BP goals
- adding a second drug from a different class should be initiated when use of a single drug in adequate doses fails to achieve the BP goal
- When BP is more than 20/10 mmHG above goal, consider initiating therapy with two drugs. Use caution in patients at risk of orthostatic hypotension
- Patients should return for follow-up and adjustment of medications at monthly intervals until goal is achieved. Appropriate laboratory tests (based on medications used) should be obtained and may be mecessary at closer intervals after initiation of therapy.
- More frequent visits may be necessary for patients with stage 2 HTN or with complicating conditions
- once BP is at goal and stable, follow-up visits can occur at less-frequent intervals
Compelling indications for HTN treatment
Ischemic Heart disease
Stable angina
- beta blocker, alternatively a long acting CCB can be used
Acute Coronary Syndrome
- initial treatment should be beta-blocker and ACEI
Post MI - ACEI, beta-blocker (for at least 3 years), aldosterone antagonist
Compelling indications for HTN treatment
Heart failure
Asymptomatic with demonstrable ventricular function
- ACEI and beta-blockers
Symptomatic ventricular dysfunction or end-stage heart disease:
- ACEI, beta-blocker, ARB, aldosterone antagonist (with loop diruretics
Compelling indications for HTN treatment
Diabetic
- Two or more often needed to achieve <140/80
- Combination should include ACEI or ARB but not both
- ACEIs and ARBs based treatments favourably affect the progression of diabetic nephropathy and reduce aluminuria
Compelling indications for HTN treatment
CKD
- GFR < 60 and presence of albuminuria
- goal of <130/80 (often require 3 or more drugs)
- ACEIs and ARBs have favorable effects on the progression of diabetic and nondiabetic renal disease. Limited rise in SCr as much as 30% above baseline is acceptable
Compelling indications for HTN treatment
Cerebrovascular disease
-recurrent stroke rates are lowered by the combination of an ACEI and a thiazide diuretic
Other potential effects of antihypertensive drug choices
Favorable
Thiazides
- slow demineralization in osteoporosis
Beta-blocker
- treat atrial fibrillation and tachyarrythmias, angina, migraine prophylaxis, and essential tremor
CCB
- treat Raynaud syndrome and certain arrythmias, migraine prophylaxis
Alpha-blockers
- used in prostatism
ACEIs
- may show favourable effect on blood glucose
Other potential effects of antihypertensive drug choices
Unfavorable
Thiazides
- use with caution in gout or hyponatremia
- may negatively affect blood glucose
Beta-blocker
- use caution with asthma or heart block
- may negatively affect blood glucose (except carvedilol
ACEI or ARB
- avoid in women who are, or are likely to become, pregnant
Aldosterone antagonists and K sparing diuretics
- avoid in patients with K values greater than 5.0 mEq/L or CrCl < 30ml/min