HTN 2 Drugs 2 Flashcards
CCBs and Direct Vasodilators are
approaching the vasculature Directly
Calcium Channel Blockers (CCBs) have two categories ____ , but where their effect is different
Dihydropyridine
Non-dihydropyridine
Calcium Channel Blockers (CCBs) MOA
MOA: vasodilator activity by inhibiting Ca2+ influx across slow channels of vascular smooth muscle and myocardium during depolarization, relaxing the coronary vascular smooth muscle and coronary vasodilation.
Non-Dihydropyridine CCB MOA
Decrease contractility → decrease SV → decreases CO
cardiac smooth muscle calcium channels
Dihydropyridine-CCB → MOA
dilate peripheral arterioles → decrease PVR
periphery smooth muscle channels
Dihydropyridine CCBs MOA ( )
MOA: Act on vascular smooth muscle → Dilate peripheral arterioles (↓PVR)
Dihydropyridine CCBs ARE
Amlodipine (Norvasc) 5 – 10 Daily
Nifedipine, long acting (Adalat CC,
Nifedical XL, Procardia XL)
60 - 120 Daily
Non-Dihydropyridine CCBs MOA ()
- Decrease HR and conduction across the AV node
- Negative inotropic and negative chronotropic effects
- ↓ contractility → ↓ SV → ↓ CO
Non-Dihydropyridine CCBs are
Diltiazem 120 – 540 Daily
Verapamil 120 – 480 Daily (sometimes BID)
Clinical Considerations: DHP CCBs are
First-line therapy ACC/AHA guidelines (without compelling indications)
Preferred therapy in black patients
Effective in older patients with isolated systolic hypertension
Also indicated in stable CAD
Clinical Considerations: Non DHP (Diltaizam and Verapamil) CCBs are
- Indicated for cardiac focused benefit
- Angina (stable)
- Atrial fibrillation / flutter
- PSVT (paroxysmal supraventricular tachycardia)
When in hospital in an acute situation these agents along with BB help lowering blood pressure
• Verapamil is very helpful in
migraine prophylaxis
The adverse effect of Non-DHP (Verapamil, Diltiazem)are
Bradycardia (Verapamil, Diltiazem)
Constipation (verapamil)
The adverse effect of DHP CCBs (amlodipine, Nifedipine)
Reflex tachycardia (DHPs) Pedal Edema is ADEs can come from vasodilation of periphery(more frequently DHP)
MIX ADVERSE effect of CCB are
Gingival hyperplasia
Headache
Orthostatic hypotension
Dizziness
(Diltiazam and verapamil )Non-DHP contraindications are
Heart block
HF
Avoid use with beta-blockers
Pt with HF (ok to use amlodipine or felodipine as they are safe to use)
Drug interactions: of p450 are
Verapamil, diltiazem are P450 substrates
Simvastatin dosing limitations are
With Amlodipine - no more than 20mg of simvastatin
Verapamil & diltiazem - no more than 10mg
Direct Vasodilators MOA
Act directly on vascular smooth muscle to dilate arterioles (not veins)
BP = CO x PVR
Lower BP via ↓ PVR
When PVR go down by having Direct Vasodialtor we have
Tachycardia
Direct Vasodilators are
Minoxidil (Loniten) 10 – 40 1-2
Hydralazine (Apresoline) 20 – 200 2-4
Hydralazine is used for people as an add on
Resistant HTN
Clinical considerations OF Direct vasodilator are:
Not considered first-line agents
Considered 4th-line or later
Likely add-on in resistant HTN
Topical minoxidil indicated in alopecia
Topical minoxidil indicated in
alopecia
Every hair growth OTC have ___ in it
Minoxidil
ADEs of direct vasodilator are
- Reflex tachycardia, palpitations
- Headache, dizziness
- Na+/H2O retention
- Hirsutism (minoxidil)
- Lupus-like syndrome (higher doses of hydralazine)
Diuretics are
Thiazide
Loop
Potassium sparing
Thiazide Diuretics MOA
Inhibit NaCl reabsorption in the distal convoluted tubule (DCT)
increase Na+ and H2O excretion
• BP = CO X PVR
Decrease in Vol, decrease in preload, Decrease in SV and decrease in CO
Thiazide Diuretics: are
Hydrochlorothiazide (HCTZ) 12.5 – 25 (no use in going to 50mg) Daily
Chlorthalidone 12.5 – 50 Daily
A thiazide that should be switched from ______ to ______
HCTZ, Chlorthalidone
Clinical Considerations of Thiazide diuretics
They cause HYPOkalemia
Do not use if significant allergy hx with sulfonamides (e.g., Bactrim)
When switching: 12.5 mg dose of chlorthalidone is equivalent to 25 mg of HCTZ means chlorthalidone is more potent
Little efficacy in CrCl < 30ml/min
Loop Diuretics MOA
selectively inhibit NaCl reabsorption in the thick ascending limb of the Loop of Henle
_______ are better than loop dieuretics
THiazide dieuretics
Loop Diuretic are
Furosemide (Lasix) 20 – 80 1-2
Clinical Considerations: LOOP diuretics are
Can result in hypokalemia: Give with K+supplement if needed
Someone with a Sulfur allergy should avoid Loop diuretic
Loops most potent (work at CrCl <30 ml/min)
Preferred in symptomatic HF and mod-to-severe CKD (eGFR<30)
Bumetanide 1mg is equal to
= torsemide 20mg = furosemide 40mg
K-Sparing Diuretics MOA
MOA: reduce Na+reabsorption into the collecting ducts/tubules
K-Sparing Diuretics are
Triamterene
Clinical Considerations: of K-Sparing Diuretics are
Not recommended for initial tx of HTN per ACC/AHA and JNC8
Avoid in pts with significant CKD
Contraindicated if K > 5.5, receiving K-supplements, or on meds that can increase K
_____ and ______ can cause Hyper uricemia so people with
Thiazide and Loop, Gout need to be cautious
K+ sparing dieuretics can
primarily used to prevent hypokalemia caused by other agents (i.e., thiazide or loop diuretics) so avoid with ACE/ARB and
Drug Interactions: All Diuretics are contraindicated with
NSAIDs
ACEI/ARBs (K+-sparing diuretics only)
High salt foods – less efficacy
Monitor labs and effects in all diuretics for
Basic metabolic panel 2-4 weeks after initiation or dose
increase: renal function (Cr, BUN), electrolytes (Na, K, etc..)
• Uric acid, BG
All Diuretics can cause Dehydration which can cause
Hypotension sx (esp with position change)
All dieuretics caution
Gout history • Renal insufficiency • Volume depletion • Elderly • History of urinary issues (incontinence, BPH sx in men) • Adherence (? Skipping doses) • Blood sugar • Tinnitus (loops
Preferred therapy in black patients are
Amlodipine , nifedapine
When in hospital in an acute situation _______ agents along with BB help lowering blood pressure
Verapamil and Diltiazam
what medication is Effective in older patients with isolated systolic hypertension
Amplodipine and Nifedapine
Non dihydropyridine work on what part of the heart
(cardiac smooth muscle calcium channels)
Dihydropyridine work on what part of the heart
(periphery smooth muscle channels)
(higher doses of hydralazine) can cause
Lupus-like syndrome
Avoid use of beta-blockers with
Diltiazam and verapamil