Pharm: Cardiac Drugs Flashcards
MOA of Methyldopa. Side effect?
Methyldopa is a centrally acting a2-agonist which reduces cardiac output or vascular resistance.
May cause hemolytic anemia
A cheese lover on MAO inhibitor experienced a hypertensive crisis. How did this happen?
Large amounts of tyramine in cheese may cause release of large amounts of neurotransmitters. Tyramine normally had low bioavailability because of its metabolism by MAO.
Beta blocker with direct vasodilator action
Nebivolol
What is the MOA of the ff vasodilators:
- Hydralazine
- Verapamil
- Fenoldopam
- Minoxidil
- Release of NO from drug or endothelium
- Reduction of Ca influx via L-type channels
- Activation of dopamine D1 receptors
- Hyperpolarization due to opening of K channels
Anti hypertensive used topically in the treatment of baldness
Minoxidil
Thiazides derivative that lacks diuretic effects; given as an anti hypertensive because it causes hyper polarization and relaxation of smooth muscles
Diazoxide
Inhibits renin’s action on its substrate, angiotensinogen. What are its major toxicities?
Aliskiren.
Headache and diarrhea
Recent evidence suggest that the MOA of ranolazine as an anti-anginal drug is related to:
Inhibition of late Na current
5 mechanisms/drug classes for sympathiplegic control of blood pressure.
1) baroreceptor sensitizing agents
2) CNS sympathetic outflow blockers
3) ganglion blockers
4) nerve terminal blockers
5) adrenergic blockers
What loop diuretic has no sulfa group?
Ethacrynic acid
What is the most potent loop diuretic?
Bumetanide. Also does not need to be bound to albumin.
Gravest side effect of reserpine
Severe psychiatric depression with suicidal ideations
Feared side effects of alpha 1 selective blockers
1st dose orthostatic hypertension
Feared side effect of methyldopa
Immunologic mediated hemolytic anemia (+) Coombs test.
What beta blocker is used to treat pheochromocytoma?
Labetalol
Aside from blocking sympathetic effects on the heart, what is the other mechanism of action of beta blockers?
Decreases renin release
What are the common causes of drug induced lupus?
Hydralazine
Isoniazid
Procainamide
Penicillamine
What vasodilators are specific for arterioles?
Hydralazine
Minodixil
Nitroprusside
Marker for drug induced lupus
Antihistone 95% sensitive
What CCB causes gingival hyperplasia?
Nifedipine
Cyclosporine
Phenytoin
Verapamil
Which CCB is preferential for cardiac L-type calcium channels?
Non-dihydropyridines
What is the dopamine agonist that increases renal blood flow by dilating afferent and efferent arterioles?
Fenoldepam
What are 2 mechanisms by which ACEI protect diabetic kidneys?
ACEIs inhibit albumin excretion and slowdown progression to macroalbuminuria.
Secondary effect: decrease compensatory hypertrophy of nephrons
Vasodilator used in the treatment of insulinomas
Diazoxide
Decreases insulin release from islet of Langerhans
What vasodilator is known to cause coronary steal syndrome?
Nitroprusside.
According to ALLHAT and NKF-ADA, what drugs should be given to patients with DM? Provided they still have good kidney function, CKD 2.
Diuretic, BB, ACEI or ARB, CCB, aldosterone antagonist
Vasospastic angina is responsible for how many % of anginal cases?
10%
Mechanism of action of pFOX inhibitors?
Shifts fatty acid metabolism to more efficient glucose use in cardiac muscle.
Give an example of a 3-KAT inhibitor.
Trimetazidine. Shifts fatty acid to glucose metabolism in cardiac cells
Cause of nitrate induced headaches?
Meningeal artery vasodilation
Rapid infusion of nifedipine cause cardiotoxicity by what mechanism?
Rapid vasodilation > significant lowered BP > increased sympa outflow > increased HR > increased myocardial O2 demand
What drug in the treatment of cyanide toxicity forms a less toxic and easily excretable metabolite?
What is the metabolite?
IV sodium thiosulfate
Thiocyanate
Inhaled amyl nitrite and sodium nitrates cause?
Methemoglobinemia, which has increase affinity for cyanide
After how long does or develop a tolerance to nitroglycerin transdermal patches?
8-10 hours
Rare toxic effect of diltiazem that primarily affects the extremities.
Raynaud’s phenomenon
What drugs causes Raynaud’s phenomenon?
Diltiazem, some beta blockers, chemotherapeutic drugs, smoking
What drug class when combined with beta blockers has decreased side effects?
Nitrates
ECG findings in digitalis toxicity
1) most common: bradycardia
2) scooped out ST segment
3) prolonged PR interval
More specific:
4) bidirectional vent. Tachycardia
5) atrial fibrillation with slow ventricular rate
6) atrial tachycardia with a block
What drug used in acute treatment of heart failure increase mortality when used for chronic HF?
Phophodiesterase inhibitors
What drug significantly improves functional status in CHF but not prolong life?
Digoxin
Drug of choice in the treatment of digitalis toxicity?
Lidocaine
What diuretics has significant long term benefits in HF?
Spironolactone and epleronone
What drugs have been shown to have survival benefits for HF?
ACEIs
beta blockers
Aldosterone antagonists
Give the Singh-Vaughan Classification of antiarrhythmics:
1) Na channel blockers
2) Beta blockers
3) potassium channel blockers
4) CCBs
Most selective class 1 antiarrhythmic for ischemic tissue.
1B
Lidocaine, tocainide, mexiletine
What antiarrhyhtmic has the deadly side effect of agranulocytosis?
Tocainide
What class 1 antiarrhythmic is used to treat malaria
Quinidine
Quinidine’s unique side effect among the antiarrhythmics?
ITP
Treatment for class 1A overdose with arryhythmia?
Sodium lactate
Last resort antiarrhytmic known to have a proarrhythmic effect?
Flecainide
Ideal treatment for Wolf-parkinson-white?
Procainamide or Amiodarone.
Don’t forget cardioversion is the best option!
What 2 class 3 drugs also have class 2 effects?
Amiodarone and sotalol
What class of antiarrhythmics is characterized by prolongation of the action potential?
Class 3 & (minor class 1A) Caused by blockade of Ik channels that are responsible for repolarization thereby increasing effective refractory period.
Amiodarone like drug with less side effects used for the treatment of atrial flutter?
Dronedarone
What drug leaves microcrystalline deposits on the skin and cornea?
Amiodarone
Why are dihydropyridines not used as antiarrhythmics?
They evoke a compensatory sympathetic response that facilitates arryhythmia rather than terminating them.
Transient chest pain is a notable side effect of adenosine, why?
It causes mild to moderate bronchoconstriction
What diuretic group does not act on the luminal side?
Aldosterone receptor antagonists
What drug blocks the excretion of weak acids and bases at the PCT
Probenecid
What causes hep enceph in patients receiving acetazplamide?
Acetazolamide causes alkalinization of urine due to decreased bicarbonate reabsorption. This prevents ammonia from turning to ammonium. Ammonia is more easily reabsorbed.
Parathyroid hormone shares several renal effects with what diuretic?
Thiazides diuretics
What diuretic mimics the effect of gitelman syndrome?
Thiazide diuretics
What diuretic mimics bartter syndrome?
Loop diuretics
Only for type 1 Bartter syndrome
What diuretics cause acidosis?
Acetazolamide by decreased bicarbonate reabsorption
Spironolactone by decreased H+ secretion
What drugs cause hypochloremic, hypokalemic metabolic alkalosis?
Thiazides and Loop D’s.
Drug of choice for central diabetes insipidus
Desmopressin
Drug of choice for nephrogenic DI?
Thiazides
Drug used for Von Willebrands disease?
Desmopressin
MAO inhibitors were once used for HPB because they caused formation of this false neurotransmitter in postganglionic neuron terminals which had very low efficacy.
Octopamine
