antianginal drugs Flashcards
angina def
episodes of reversible myocardial ischemia,
inducible by exercise, emotion or other stress;
It is reproducible and are commonly associated with transient chest discomfort.
Classification according to the new york heart association
Class I : No limitation of physical activity (Ordinary physical activity does not cause symptoms).
Class II : Slight limitation of physical activity (Ordinary physical activity does cause symptoms).
Class III : Moderate limitation of activity (Patient is comfortable at rest, but less than ordinary activities cause symptoms).
Class IV : Unable to perform any physical activity without discomfort, therefore severe limitation (Patient may be symptomatic even at rest).
3 groups of drugs according to their effect in angin a
- symptomatic relievers
- prognosis improvers
- metabolic agents
list the symptomatic releiver drugs
bb
ccb
organic nitrates
selective if inhibitors
list the prognostic improving drugs
antiplatelets
statins
ace inhibitors
arbs
list the metabolic agents
trmetazidine
ranolazine
effects of bb on the heart in angina
Prolong diastole(-ve dromotropy)> Increase perfusion of ischemic areas -ve chromotropy Reduce 02 demand -ve inotropism -ve chromotropism These 2 effects reduce blood pressure
indications of bb in angina
Post MI
Stable angina w/o CI
Silent ischemia
Cold induced angina ( just as effective as CCB)
drug combo of bb in angina
COMBO w/ dihydropyridines
Combo w/ nitrates
Never w/ non dihydro’s- same action => HF and Hypotension.
Not w/ neuroleptics-> hypotension
bb used in angina w/ co-existing systolic heart failure
β1-selective blockers BISOPROLOL and METROPOLOL, or a
beta-blocker with additional vasodilating effects (CARVEDILOL and NEVIBILOL) in gradually increasing doses
bb used in angina w/ thyrotoxicosis
beta-blockers W/O intrinsic sympathomimetic activity e.g.
PROPANOLOL
(blocks the conversion of T4 to T3).
bb used in angina w/ liver failure
hydrophilic beta-blockers (atenolol) due to renal excretion,
beta-blockers with dual route of elimination – urine and bile (bisoprolol).
bb used in angina w/ renal insufficiency
FAT SOL beta-blockers because they undergo extensive first-pass metabolism in the liver.
propanolol & metropolol
dosing principles of bb in angina
HR at rest should be: 55-60bpm
HR at exertion: max 75% of resting HR / 100BPM
Severe stable: <50bpm w/o CM’s of bradycardia heart block
ECG stress test is reduced while using BB
dihidropyridine classification
1st gen: nifedipine: 10 mg. short acting. 3x/24hr. Blocks Ca2+ in vascular smooth muscle->VD->increased myocardial bf and O2 supply
2nd gen: felodioine: 10mg. Imdt acting. 2x/day
3rd gen: amlodipine: 10mg. Long acting
non dihydriopryidine classification
Inferior to BB post MI, and in CHF
Used when BB
verapamil
diltiazem
when are CCB used
when BB are contraindicated
Ideal for prinzmetal angina as they prevent spazm. BB favour spasm in prinzemetal due to unopposed alpha receptor action
which class of ccb is preferred in systolic heart failure
DHP> non DHP
non DHP reduce CO
which class of ccb is preferred in renal failuire
non DHP> DHP
because DHP strongly bind to pp but hypoproteinemia occurs in renal failure -> increased level of free drugs-> increased toxic
drug combo of CCB
DHP combo w/ bb not non DHP-same effect
Non DHP comb w/ nitrates, not DHP-same vasodilating effect -> hypotensh
classification of organic nitrates
Glyceryl trinitrate
Nitroglycerin – sublingual tab. 0,5 mg;
Nitroglycerine – lingual aerosol (each dose contains 0,4 mg).
Isosorbide mononitrate - tab. 20 mg
Isosorbide dinitrate - tab. 10 mg, slow release tab. 40 mg; spray (each dose contains 1,25 mg) 15 ml.
effects of organic nitrates on the heart in angina
- dilate venous capacitance vessels and lower left ventricular filling pressure (“preload”).
- dilate arterial resistance vessels and reduce ventricular emptying (“afterload”).
- Reduce myocardial oxygen demand
- have little effect on the total coronary flow but improve the blood flow through collateral vessels.
-relieve coronary artery spasm.
Increase myocardial oxygen supply
-Don’t actually reduce mortality of angina only symptoms
when are nitrates prescribed over CCB
if the dual therapy of BB and CCB is ineffective
short acting nitrates
Nitroglycerin spray: faster acting
Nitroglycerin sublingual
standard initial therapy for effort angina.
- (0.3–0.6 mg) every 5 min until the pain goes/
- a maximum of 1.2 mg has been taken within 15 min.
- patient should rest sitting (standing promotes syncope,
- lying down enhances venous return and heart work)
Isosorbide sublingual
-slower onset of anti-anginal action than nitroglycerin
because the dinitrate requires hepatic conversion to the mononitrate.
Effect lasts for about 1 h.
