Nitrates + Everything else (Stable Angina CAD) Flashcards
Nitrates MOA
Short and long acting forms
Mixed venous AND arterial dilating drugs Venous>arterial dilation ↑ venous capacity ↓ventricular preload improved venous and later arterial filling
Nitrates Indications
Adjunctive
To reduce sx (only) aka sx relief!!!! NO CV outcome
Controls SX and delays ED/urgent care visits
Nitrates Metabolism
glutathione depletion is:
extensive 1st pass met with ORAL nitrates
SL rout avoids 1st pass = rapid vasodilation but only lasts for 30 min
glutathione depletion = nitrate tolerance Bioactivated- needs redox: small amount gets into circulation and depletes glutathione causing tolerance so don’t use less then 12 hrs apart!
Nitrates- monitor
Monitor: anginal relief (frequency of anginal episodes), activity tolerance, ortho hypo
Intolerance/toxicity: activity intolerance or worsening angina, hypotension, orthostasis, dizzy, h/a, blurry vision, perioheral edema, falls, reflux
Nitrates SE
- Orthostasis from venous pooling (dangerous if dehydrated, upright, not moving, or etoh)
- Temporal and meningeal arteries vasodilate—intense headache 60%
- Rebound tachycardia & enhanced Na retention in response to venous dilatation
- nitrate tachyphylaxis from long term exposure to short acting nitrates(sulfahydryl/glutathione depletion)
- nitrate toxicity
Nitrates Considerations
Reduces hospitalizations
No cv outcome
hold phosphdieesterase inhibitors for 24 hrs after giving nitrate circulatory collapse from too much dilating
Nitroglycerine MOA
Vascular smooth muscle relaxes via increased cGMP
↓O2 demand, preload, afterload, SX, hospitalizations
improved collaterals
NTG indications
Rapid relief of angina—not for background vasodilation
can be used to prevent exercised induced angina
Paste:1-2 inches applied to chest wall USE GLOVES
Patch: clean dry skin for 12 hrs on, then off 12 hrs
NTG metabolism
SL duration: 20-30 min
TD duration: 6-8 hrs remove patches before MI and defibrillation
Half life 1-4 minutes
Nitrate free interval of 10-12 hrs required to avoid tolerance to oral
Give first dose under observation for h/a or reflux
NTG DI
NO ALCOHOL!!
NTG SE/ Considerations
(if they don’t improve call asap bc prob ACS not stable CAD)—take 2 doses every 5 min while waiting
Isosorbide Mononitrate MOA
Systemic vasodilation by increasing cGMP
↓preload, LV end diastolic volume and pressure
Isosorbide Mononitrate indications
Tx sx only—24 hour control of angina
Can be added with SL nitroglycerine
Isosorbide Mononitrate
Metabolism
XR tablet allows increase of dose every 3 days—make sure the pt isn’t confusing this with SL nitro or chewing this like ASA
schedule adjust for nocturnal angina
Isosorbide Mononitrate DI
NO alcohol!!!!
Space PDE5 inhibitors 24 hrs apart
Ranolazine MOA
Inhibits late phase Na current in ischemic myocytes
Reduces intracellular Na = reduced Ca influx
–aka it decreases Na/Ca exchange
reduction in Ca = reduced ventricular wall tension and MVO2 = enhanced metabolic efficiency without changing hemodynamics: no change in bp or hr!! ****
Ranolazine Indications
Use when BB, CCB, and nitrates are maximized to increase functional tolerance –helps with cardiac rehab too
Ranolazine metabolism
Higher doses inhibit delayed rectifier K current = prolongs ventricular contraction and QT interval (can lead to vtach and sudden death!)
Met by CYP3A4
Ranolazine cosiderations
Limit dose with verapamil/diltiazem and substrate/inhibitors of P gylcoproteins
*improves tradmill exercise tol by 30 seconds
Ivabradine MOA
Selective Na channel blocker reduces HR, and hyperpolarizes the SA node: alternative node blocker
Ivabradine Indications
Pts with LVD, HF with EF 35-40%, stable CAD if HR >70,
Considered in HF/LVD when BB, digoxin not tolerated
Ivabradine Metabolism
Mod CYP3A4 substrate
PGP inhibitor
Half life 6 hrs
70% protein bound
Hepatic metabolism
Metabolite has 40% of parent activity
Ivabradine considerations
Food increases exposure 20-40%
Can cause new AF, bradycardia, av block sick sinus dynrome: decompression (better used in pts with higher HR)
Max Medical Management
Aspirin +/- Clopidogrel (if stented) Ace-I/ARBs, BBlockers, BP management Statins: LDL tx goals or minimum 40% reduction from baseline Quit smoking Treat depression Nutritionist –cals, food quality, fiber CV rehab, personal trainer Bmi 25-27 Cal expenditure targets