HTN Drugs - Kruse Flashcards
4 categories of HTN drugs
- Vasodilators
- Sympathetic antagonists
- Diuretics
- ACE Inhibitors/ARBs
How to use vasodilator drugs?
W/ diuretic or beta blocker – for compensatory tachycardia, salt/water retention, etc.
Classes of vasodilator drugs
- Calcium channel blockers (DHP, non-DHP)
- Potassium channel openers
- D1 agonists
- N.O. release agents
Function of calcium channel blockers
Channel types?
Block L-type (voltage-gated) Ca++ channels to reduce frequency of opening w/ depol.
- Vascular channels = vasodilate
- Cardiac channels = decreased ht function
When not to use CCBs
Heart slowing failure of any kind (CHF, bradycardia, heart block)
Types of CCBs
- DHPs = vascular selective
- Non-DHPs = both L-type channels
DHP CCB drug names
- Nifedipine
- Amlodipine
Non-DHP CCB drug names
- Verapamil
- Diltiazem
Nifedipine vs. Amlodipine
Both DHP CCBs
N = short acting, no AV problems A = long acting, some AV problems
Nifedipine vs. Amlodipine:
Use when?
Don’t use when?
N - use for AV conduction abnormality, short term. DON’T USE for chronic HTN
A - use for angina or HTN. DON’T USE for heart failure
Verapamil and Diltiazem (Non-use)
Both non-DHP CCBs
- Decrease vascular AND cardiac mm. fxn - NOT w/ BETA BLOCKER
Verapamil side effect
Constipation
Diltiazem side effect
Facial rash
A patient is on Nifedipine or Amlodipine. What else should they be on?
Other vasodilator (CCB, K+ channel opener, D1 agonist, N.O. modulator)
K+ channel opener drug names
Function?
- Diazoxide
- Minoxidil
Relax smooth muscle (hyperpolarize)
Diazoxide
Long-acting K+ channel opener
Injections
USE - hypertensive emergency
DON’T - renal failure, beta blockers, ischemic ht disease
Minoxidil
K+ channel opener
Pro-drug
Use with BETA-BLOCKER and LOOP DIURETIC
USE - long term outpatient severe HTN
Side effects of Minoxidil
- HA, sweating, hair growth (Rogaine)
- REFLEX SNS stimulation –> tachycardia, palpitations, angina, edema
Fenoldopam
D1 agonist Peripheral vasodilation Needs continuous IV for short 1/2 life USE - HTN emergency, operative HTN DON'T - glaucoma (increased IOP) S.E.'s = reflex SNS, HA, sweating
N.O. release drugs
Function?
- Hydralazine
- Nitroprusside
Arteriolar dilation via cGMP
Hydralazine:
Function?
Use? (alone)
Don’t?
Side effects?
Fxn = N.O. release (cGMP)
Use - long term HTN
Don’t - Ischemic ht disease
Sides = reflex tach (could lead to arrhythmias in ischemic heart disease)
When might hydralazine be used in combo with something else? (2)
HTN + heart failure = Hydralazine + nitrates
HTN + pregnancy = Hydralazine + methyldopa
Nitroprusside:
Function?
Use?
Side effects?
Fxn = Metabolized into N.O. –> dilates ALL
- Rapid on, rapid off (continuous IV needed)
Use - HTN emergencies, acute decompensated heart failure, aortic dissection
Sides = Cyanide poisoning (chronic use)
Nitroglycerin:
Function?
Use?
Don’t?
Side effects?
Fxn = N.O. release (VEINS smooth muscle)
Use - HTN emergencies, angina, heart failure
Don’t - Increased ICP, PDE5 inhibitors (-afil) (worsened hypotension)
Sides = Tolerance (use 8 hrs between), hypotension, syncope, THROBBING HA’s
How to use sympathoplegic drugs?
With a diuretic (avoid compensatory Na/H2O retention due to hypotension)