Angina Flashcards
Pathophysiology
Angina
The result of an imbalance between the myocardial oxygen supply and the myocardial oxygen demand
Signs and symptoms
Angina
- Dizziness
- Fatigue
- Nausea
- Shortness of breath
- Sweating
Rationale for drug use
Angina
Provide symptom relief.
Reduce risk of death or MI.
Drug treatment plan
Angina
- beta blocker (atenolol OR metoprolol - HFrEF)
- nonhydropyridine calcium channel blocker (diltiazem, verapamil)
- Beta blocker + dihydropyridine calcium channel blocker (amlodipine)
- Add long-acting nitrate (transdermal glyceryl trinitrate to (1) OR (2)
For a patient with stable angina, beta blockers are usually first-line therapy to prevent episodes of angina, unless contraindicated. There is some evidence that beta blockers reduce incidence of recurrent myocardial infarction. Use:
**1atenolol 25 mg orally, daily, increasing if required up to 100 mg daily **
pts with left ventricular function <40% (HFrEF) should use beta blockers with cardiac benefits (metoprolol)
Nondihydropyridine calcium channel blockers (diltiazem, verapamil) used if beta blockers aren’t tolerated
What is stable angina
Angina is defined as retrosternal chest discomfort (pain or tightness) that lasts 10 minutes or less and subsides promptly with rest. It occurs when myocardial oxygen demand exceeds supply, which is usually restricted by atherosclerotic obstruction. Angina is commonly triggered by physical activity or emotional stress.
Angina is considered stable if the pattern of symptoms has not changed during the past month (eg the distance walked before the development of angina, when allowing for terrain, meals or cold weather).
Two kinds of Calcium channel blockers
Dihydropyridines
Non-dihydropyridines
suffix
Dihydropyridines Calcium channel blocker
Pine
Generic names of Dihydropyridines Calcium channel blocker
Amlodipine
Amlodipine with atorvastatin
Amlodipine with valsartan
Amlodipine with valsartan and hydrochlorothiazide
Clevidipine
Felodipine
Lercanidipine
Lercanidipine with enalapril
Nifedipine
Nimodipine
Generic names of Non-dihydropyridines Calcium channel blockers
Diltiazem
Verapamil
Trandolapril with verapamil
Indication
Calcium channel blockers
Hypertension
Angina
MOA
Calcium channel blockers
Block inward current of calcium into cells in vascular smooth muscle, myocardium and cardiac conducting system via L‑type calcium channels.
Act on coronary arteriolar smooth muscle to reduce vascular resistance and myocardial oxygen requirements, relieving angina symptoms.
Dihydropyridines act mainly on arteriolar smooth muscle to reduce peripheral vascular resistance and BP. They have minimal effect on myocardial cells.
Non-dihydropyridines: diltiazem and verapamil act on cardiac and arteriolar smooth muscle. They reduce cardiac contractility, heart rate and conduction, with verapamil having the greater effect. Diltiazem has a greater effect on arteriolar smooth muscle than verapamil.
Precautions
Calcium channel blockers
Myasthenia-like neuromuscular disease—calcium channel blockers may increase risk of muscle weakness and respiratory depression (most case reports with verapamil).
Peritoneal dialysis—cloudy peritoneal fluid (with no signs of infection) has been reported, mostly with lercanidipine; it is not clear if this is a class effect.
Adverse effects
Calcium channel blockers
Most listed adverse effects occur with all calcium channel blockers.
Adverse effects vary between the calcium channel blockers according to their relative effects on vascular, myocardial and conducting tissue.
Dihydropyridines have more pronounced vasodilatory effects than diltiazem and verapamil. Verapamil, and to a lesser extent, diltiazem, reduce cardiac contractility, heart rate and conduction.
Peripheral oedema
Dihydropyridines commonly cause peripheral oedema due to redistribution of extracellular fluid (rather than fluid retention); this does not respond to treatment with diuretics, which may put patient at risk of volume depletion.
Practice points
Calcium channel blockers
vasodilatory adverse effects usually subside with continued treatment (may require dose reduction)
Drug class and indication
Amlodipine
Dihydropyridine Calcium channel blocker
Hypertension
Angina
Drug class and indication
Amlodipine with atorvastatin
Dihydropyridine Calcium channel blocker + statin / HMG-CoA reductase inhibitors
Hypertension or angina, in patients with hypercholesterolaemia or multiple cardiovascular risk factors
Drug class and indication
Amlodipine with valsartan
Dihydropyridine Calcium channel blocker + sartan (ARA)
Hypertension
Sartan a.k.a. angiotensin II antagonists and angiotensin receptor antago
Drug class and indication
Amlodipine with valsartan and hydrochlorothiazide
Dihydropyridine Calcium channel blocker + Sartan (ARA / ARB/ angiotensin II receptor blocker + Thiazide diuretic
Hypertension
Drug class and Indication
Clevidipine
Dihydropyridine calcium channel blocker
Hypertension (short-term use when oral treatment not appropriate)
Drug class and indication
Felodipine
Dihydropyridine calcium channel blocker
Hypertension
Drug class and indication
Lercanidipine
Dihydropyridine calcium channel blocker
Hypertension
Drug class and Indication
Lercanidipine with enalapril
Dihydropyridine calcium channel blocker + ACE inhibitor
Hypertension