HTN II Flashcards
- What BP is HTN for home monitoring?
2. 24-hr BP Dx of HTN
- > 135/85 mmHg (office measure is 140/90)
2. >130/80 mmHg
BP Follow-Up Timeline:
- Normal
- Pre-HTN
- Stage 1
- Stage 2
- Recheck in 2 years
- Recheck in 1 year
- Confirm w/in 1 month
- Evaluate or refer w/in 2 weeks
If BP is =/> 180/110, evaluate and treat immediately or within 1 week
Initial Dx of HTN: 3 key steps
- Identify possible secondary causes of high blood pressure
- Identify other cardiovascular disease
risk factors - Assess for target organ damage
Physical Exam for Dx HTN
Physical Examination • Check the BP in both arms • Obtain orthostatic blood pressures (especially elderly) • Cardiac: palpation and auscultation • Vascular: pulses, carotid, abdominal, and femoral bruits • Abdomen: masses and aortic pulsation • Lower extremities: edema • Palpate thyroid • Examine optic fundi
Initial Lab Tests
Initial Laboratory Tests • Urinalysis • Blood glucose • Hematocrit • Serum potassium • Serum calcium • Serum creatinin, GFR • 12-lead ECG • TSH • Fasting lipid panel: HDL-c, LDL-c, TGs
Major classes of anti-HTN drugs:
• Angiotensin -converting enzyme inhibitors • Angiotensin receptor blockers • Calcium channel blockers • Diuretics
Other anti-HTN drugs
• β-Blockers • α-Blockers • Direct vasodilators • Aldosterone antagonists • Direct renin inhibitors • Central α2 agonists
What drugs must you not use for HTN in pregnant women?
ACE-inhibitors, angiotensin receptor blockers, renin inhibitors
ACE-inhibitors:
- Name/example:
- Mechanism
- Effects
- Side Effects
- Misc.
- “…pril”–captopril
- Bind to angiotensin converting enzyme
- Effects:
a) ++ Ang I
b) – Ang II
c) ++ Renin
d) – aldosterone
e) –peripheral arterial resistance
f) –intravascular volume - CATCHH
- Protects the kidneys: dilates vessels, lowers intraglomerular pressure
ACE-I Side Effects
CATCHH
a) Cough
++ BK in lungs
5-20%
dose-dependent
b) angioedema
*potentiation of BK
>90% can take an ARB
-usually in 1st month
-Swelling of tongue and laryngeal mucosa
•Greater risk among African
Americans
c) teratogen
- Need Ang II for fetal kidney
d) creatine bump (up to 30%)
- can cause worsening renal fxn in those with CKD, renal artery stenosis, cardiomyopathy, DM
e) hyperkalemia
- typical of all RAAS inhibitors
- Na+/K+ pump: we dump Na+ therefore we keep K+
f) hypotension-blocking RAAS
Angiotensin Receptor Blockers (ARBs)
- Name/example:
- Mechanism
- Effects
- Side Effects
- Misc.
- “…sartan”
- Selectively block AT1 receptor; thus Ang II can’t bind
- Effects:
a) ++ Renin
b) – aldosterone
c) –peripheral arterial resistance
f) –intravascular volume
g) inhibits sympa activation, vasoconstriction, cell growth, Na+ fluid retention - Similar S/E to ACE-i but better S/E profile
- hyperkalemia
- ++creatinine - No effect on BK (thus less incidence of cough and angioedema)
AT1 Receptor
Blocked by ARBs from binding Angiotensin II
Normally: vasoconstriction, sympathetic activation, cell growth, Na+ fluid retention
Diuretics:
- Mechanism
- Effects
- Side Effects
- Loop
- Thiazide
- Misc.
- Increase urinary excretion of sodium
at various sites in the kidney - Venodilation, decreases intravascular
volume, lowering blood pressure
3. Side Effects: Volume depletion • Hypotension, orthostasis • Electrolyte changes: −Hypokalemia −Hypomagnesemia −Hyponatremia (thiazide) −Hypercalcemia (thiazide) •Hyperkalemia (potassium sparing) diuretics) -stable after 1st 3-7 days • Ototoxicity (Loop) • Metabolic side effects: −Hyperglycemia −Hypercholesterolemia −Hyperuricemia (loop)-->gouty arthritis • Erectile dysfunction • Sulfa-allergy
- Loop: more potent
- ex) furosemide
- great in decompensated heart failure
- potent venodilators, natriuretic agent
- S/E: ototoxicity, ++Ca2+ excretion–>worsens osteoporosis - Thiazide
ex) hydrochlorothiazide (chlorthalidone)
- cheap and useful
- Decreases ECF and dilates peripheral arterioles
a) short term effects (1-2 weeks): decreases ECF volume, small bump in peripheral resistance, decreased BP
b) long-term effects: Steady lower levels of BP, peripheral resistance, and fluid volume
- as CO returns to baseline, SVR decreases - Not good for diabetics
Ca2+ Channel Blockers
- Mechanism
- Effects:
- Dihydropyridine
- Non-dihydropyridine
- Side Effects
- L-type Ca2+
channels: Ca2+ influx and smooth muscle contraction
•
CCBs bind
to receptors:
-vasodilate arteriolar smooth muscle
-decrease peripheral
vascular resistance - Effects:
* ++ RBF–> ++nariuresis
* dilating afferent arterioles
* ++glomerular filtration pressure - Dihydropyridine (amlodipine)
-Decrease Ca2+ influx into vascular SMCs
-chronic use-little effect on resting HR
-Can cause reflex tachycardia
S/E (due to arteriolar dilation): edema, headache, flushing, dizziness,
palpitations - Non-dihydropyridine
-verapamil, diltiazem
-also decrease Ca2+ influx into myocardium (decreases HR)
-S/E: bradycardia, AV
block, CONSTIPATION - General S/E:
-Gingival hyperplasia
-Aggravate
gastroesophageal
reflux due to
inhibition of LES
contraction
-inhibits CYP34A: increasing blood levels of other meds
-hypotension
-headache
-ankle edema
-nausea
Direct Renin Inhibitors
- Mechanism
- Warnings
- Side Effects
- Example
- Advantages?
- Blocks the “rate
limiting step” of
RAAS
2. Do not use with ACE-I or ARB: Increased incidence of nonfatal stroke, worsening kidney function especially with diabetes
3.Side effects overlap
with ACE-Is and ARBs
- Aliskiren
- ACE-Is and ARBs cause compensatory increase in renin (decreases their efficacy), whereas renin inhibitors do not