FR Review 3 - Cardiac Drugs Flashcards
Classify the four Ca channel blockers by their myocardial and vascular effects.
Verapamil: 95% heart and 5% vasculature (1st CCB)
Diltiazem: 50% heart and 50% vasculature
Nifedipine: 5% heart and 95% vasculature
Amlodipine: 1% heart and 99% vasculature
What is the primary use of verapamil and diltiazem?
Rate control in atrial fibrillation –> no use in CHF
What is the primary use of nifedipine and amlodipine?
Anti-hypertensives and safe in CHF
What is the most significant adverse effect of nifedipine and amlodipine and how is it managed?
Non-cardiogenic peripheral edema. Treat with a low dose diuretic if it bothers the patient.
Other than HTN, list and define a potential use for nifedipine.
Achalasia –> lower esophageal tone is too high
Other than the primary AE, what is another rare AE associated with nifedipine?
gingival hyperplasia
Differentiate selective from non-selective beta blockers.
Selective: block only beta-1
Non-selective: block both beta-1 and beta-2
-Goal is to block B-1 –> blocking B-2 is baggage
What is ISA in relation to beta blockers?
ISA = intrinsic sympathomimetic activity. Some beta blockers have some mild beta agonist properties. They still have more beta antagonist effects but the are less potent beta antagonists.
What is the benefit of beta blockers that also have alpha-1 antagonism and give some examples.
More potent beta blockers s/p vasodilation - useful in cocaine OD. Exs: carvbedilol, labetalol
Give three examples of commonly used beta-1 selective beta blockers.
atenolol, metoprolol, esmolol
Explain why patients on beta blockers must have them withdrawn slowly over a relatively long period of time.
While on beta blockers, the heart upregulates beta 1 receptors and increases their sensitivity. Sudden withdrawal of the medication can lead to tachycardia and hypertension.
What is unique about the pharmacokinetics of esmolol?
It is eliminated via plasma esterases (in blood), meaning the drug will have a short 1/2 life and can only be given IV.
What 3 beta blockers are used for CHF?
Carvedilol, Metoprolol XL, Bisoprolol
What are the indications for use of propranolol?
Tremor, anxiety/stage fright, aggression, thyroid storm
DOC for portal HTN
If a patient with asthma or COPD history has to be on a beta-blocker, which ones are safest?
Selective BBs –> asthma/COPD patients should not have drugs that block B-2
Describe the efect of beta blockers in patients that are prescribed an epi-pen.
BBs decrease the efficacy of epi-pens –> pateints should carry two epi-pens if they are on BBs.
Name 3 alpha-1 blockers and state the caution with these medications?
Doxazosin, Prazosin, Terazosin. They are very potent vasodilators that cause postural HypoTN and falls.
List three selective (bladder specific) alpha-1 blockers and describe their use.
Afluzosin, Silodosin, Tamsulosin. Blockade of alpha-1 in the bladder promotes urination - used in BPH.
What is the mechanism of action of clonidine?
Centrally acting alpha-2 agonist –> dec release of epi and norepi from the synapse and decreases BP
What are the indications for use of clonidine?
Last line as an anti-hypertensive
Other: ADD/ADHD, epidurals, smoke cessation
What are three actions of angiotensin II?
- potent vasoconstriction
- secretion of aldosterone retaining renal Na and H2O
- stimulates cardiac and vascular smooth muscle proliferation –> hypertrophy and dec efficiency
What is the mechanism of action of ACE Inhibitors (ACEi) and angiotensin receptor blockers (ARB)?
ACEi prevents conversion of angiotensin I to angiotensin II. ARB prevents angiotensin II from binding to receptors.
All ACEi drugs end in what suffix? List examples.
“pril” - elanapril, captopril, lisinopril, quinapril
What action of ACEi drugs may cause a dry, hacking cough?
Inhibition of kinase which increase bradykinin in lungs. Bradykinin is a vasodilator and promotes production of other vasodilators. Inc bradykinin in the lungs can also cause a cough.
How is a cough caused by an ACEi treated?
Possibly ASA or by removing the ACEi drug. DO NOT treat with cough suppressants.
Name three cough suppressants.
Benzonatate, codeine, dextromethorphan
Other than a dry cough, what other adverse effects exist with ACEi drugs?
HyperK, Angioedema (may also be caused by NSAIDs), avoid in pregnancy (especially 3rd trimester)
Describe the effect of angiotensin II and prostaglandins on the kidneys.
A2: keeps the efferent arteriole closed
PGs: keeps the afferent arteriole open
What is the caution in prescribing ACEi drugs to patients with renal disease?
Must r/o renal artery stenosis. RAS reduces blood flow to the kidney. Normally, the efferent arteriole constricts to compensate and maintain renal blood flow. If an ACEi is given, this compensatory mechanism will be taken away, and kidney injury may result.
T/F: It is sensical to have a patient on both an ACEi and an ARB.
False: non-sensical
ARB drugs end in what suffix? List some examples.
“sartan” - losartan, valsartan, telmisartan