Vasodilators in Angina Flashcards
Damage to _____ can alter the ability of coronary vasculature to dilate
endothelium
True or False: Beta blockers are typically considered first line defense against angina if they are tolerated by the patient
True
Are B-adrenergic blockers used for angina treatment?
For stable angina, YES. They decrease O2 demand through decreasing HR and contractility and they lower BP.
For variant angina (vasospastic), no. B-adrenergic blockers do not vasodilate so they don’t do anything for variant angina.
Does norepinephrine vasodilate or vasoconstrict?
Vasoconstrict. It acts on the A1 receptors
Management of angina is centered around what?
Increasing O2 supply and/or reducing O2 demand.
Which side effects are associated with amlodipine?
A. Bradycardia B. Cough C. Edema D. QT prolongation E. Hypotension F. Flushing
Edema, hypotension, flushing.
Amlodipine is a pure vasodilator so you consider the side effects that are peripheral.
It wouldn’t cause Bradycardia or QT prolongation. Cough is side effect of ACE inhibitors, not -dipines.
How do ACE inhibitors vasodilate?
They increase bradykinin which triggers eNOS (endothelial nitric oxide synthase) to create nitric oxide which causes smooth muscle relaxation/vasodilation through cGMP.
How are CCBs metabolized and what should be kept in mind?
Metabolized by cytochrome P450. Effects may fluctuate if administered with inhibitors or inducers.
Does epinephrine vasodilate or vasoconstrict?
Vasodilate. It acts on the B2 receptors
All calcium channel blockers are vaso_____.
vasodilators
What is the most common calcium channel blocker?
Amlodipine
Nitrates are the drug of choice for ______ _______ of angina.
acute exacerbation
What is the main purpose of Beta Blockers in treatment of Angina?
Decreasing myocardial O2 demand
How can verapamil cause constipation?
L-type channels in intestinal muscles causes relaxation of intestines and stops propulsion.
Coronary blood flow is decreased by increased _______
Left ventricular end diastolic pressure (preload)
Name 5 calcium channel blockers
- amlodipine
- verapamil
- diltiazem
- nifedipine
- felodipine
Of verapamil, diltiazem, and the dihydropyridines, which have the major adverse effect of hypotension?
They all do. They all vasodilate
What do you do if a patient whose angina was previously well controlled with once-daily isosorbide mononitrate states that he recently has been taking it twice a day to control angina symptoms that are occurring more frequently during early morning hours?
You should advise the patient not to take twice a day because that depletes the nitrosothiol groups necessary for NO formation (tachyphylaxis/tolerance). You should also recommend that he take the once-daily administration in the evening because some patients have worse symptoms in the morning so shifting the regimen time can help.
What are 4 contraindications for B blockers?
- Severe bradycardia
- Asthma (relative - via B2 block)
- Peripheral vascular disorders (relative - via B2 block)
- Abrupt withdrawal -> precipitates SNS overactivity
Prophylactic treatment for chronic angina is typically done with beta blockers. When would you use nitrates?
When beta-blockers are contraindicated in a particular patient or poorly tolerated, or they can be used in addition to beta blockers if angina persists with beta-blocker usage.
Is B1 selectivity in metoprolol and atenolol absolute or dose-dependent?
Dose-dependent
Do B2 receptors dilate or constrict?
dilate
What is a potential adverse reaction for ranolazine? (to do with conduction)
Can prolong the QT interval (through inhibition of HERG channel - IKr) in dose-dependent manner (higher doses)
Torsades de pointes has not been observed but use cautiously with QT-prolonging drugs
How do you treat stable angina?
Beta blockers, nitrates, calcium channel blockers
When are CCBs used in angina? (3 things)
- used for vasospastic angina
- long-acting agents are commended for stable angina if beta-blockers are contraindicated or poorly tolerated
- can be added to beta-blockers if angina persists
Broadly speaking, how do you increase O2 supply and reduce O2 demand?
Increasing O2 supply is done surgically (CABG/PTCA) or secondarily with vasodilator drugs. Decreasing myocardial O2 demand is achieved pharmacologically with vasodilators and negative inotropic and chronotropic agents.
Name the vasodilator that is a sustained release preparation that is used chronically PO.
Isosorbide mononitrate
Nitrates result in reduction of what two things?
- Reduced Left Ventricular End Diastolic Pressure (leads to decreased wall tension => decreased myocardial O2 demand)
- Reduced systemic vascular resistance
How do you increase regional flow distribution to increase myocardial oxygen supply?
Nitrates, CCBs, B-blockers
How do you decrease preload => decrease ventricular volume and pressure => decrease myocardial wall tension => lower myocardial oxygen demand?
Nitrates
What is something to consider with continuous exposure of nitrates?
Tachyphylaxis (tolerance). This happens because of depletion of nitrosothiol groups necessary for NO formation. Nitrate free interval of 6-14 hours is recommended (typically during sleep)
Of Verapamil, diltiazem, and the dihydropyridines, which has the most major adverse effects?
Verapamil (hypotension, bradycardia, avblock, CHF, and constipation)
Which CCB is most likely to cause constipation?
Verapamil
For drug administration, wtf does Dr. French mean with SL and TS?
SL = sublingual, TS = translingual spray
Which b-blocker is a1, b1, and b2 (vasodilating)?
Labetalol, carvedilol
What is the mechanism for nitrates and PDE 5 inhibitor DDI?
Sildenafil, tadalafil, and vardenafil are erectile dysfunction drugs that are PDE inhibitors. They prevent the breakdown of cGMP so that vasodilation persist for the erection. Nitrates create excess NO which also increases cGMP which causes even more vasodilation causing a dangerous drop in BP resulting in syncope or worse.
What are 5 adverse reactions of ranolazine?
- bradycardia
- hypotension
- palpitations
- edema
- QT interval prolongation (possible)
Nitrates dilate primarily on the ____ side.
Primarily venous side. But not exclusively… it’s dose dependent