Beta blockers, the two kinds of calcium channel blocker and the nitrates side by side, with the two vasculoprotective add-ons: how each works, what it does to heart rate and pressure, where it fits, what to watch and when not to use it.
| Class and examples | How it works (oxygen demand and supply) | Effect on heart rate, contractility and wall tension | Place in therapy and coexisting conditions | Main adverse effects | Do not use / avoid | Patient education and monitoring | Source |
|---|---|---|---|---|---|---|---|
| Beta blockers metoprolol, atenolol (beta-1 selective); propranolol, nadolol (non-selective); carvedilol, labetalol (third generation) | Lower oxygen demand only; no effect on oxygen supply. | Heart rate falls markedly; contractility falls; systolic blood pressure falls; left ventricular volume rises. | First line in the absence of contraindications. First line when there is hypertension, a prior myocardial infarction or decreased left ventricular function. In diabetes a cardioselective beta blocker is an alternative (course table). Also useful in anxiety, supraventricular arrhythmias and stable (compensated) heart failure. | Hypotension, bradycardia, hyperglycemia, dyslipidemia, fatigue, sexual dysfunction, nightmares, worsened claudication. | Contraindicated: heart rate below 60, systolic pressure below 100 mmHg, atrioventricular block, acute decompensated heart failure. Avoid all beta blockers in bradycardia, atrioventricular block and variant angina; avoid non-cardioselective agents in asthma and in diabetes (course table). | Avoid rapid discontinuation (stop gradually; added background: rebound angina and myocardial infarction, with a Food and Drug Administration (FDA) boxed warning on several agents); dizziness and fatigue. Monitor heart rate, blood sugar and lipids. | L8 slide 17 slide 16 slide 18 slide 19 slide 34 slide 39 |
| Dihydropyridine calcium channel blockers nifedipine, amlodipine, felodipine | Lower demand and help supply: mild dilation in areas of fixed stenosis and relief of vasospasm. | Heart rate rises (reflex) with nifedipine and felodipine, but amlodipine leaves it unchanged; contractility unchanged or decreased; systolic blood pressure falls markedly; left ventricular volume unchanged or decreased. Strongest vasodilation (four plus); atrioventricular conduction unchanged. | Added to a beta blocker when the beta blocker alone is not successful; also combined with long-acting nitrates. Chosen (as a class) for vasospastic angina, asthma, severe peripheral vascular disease and uncontrolled diabetes; left ventricular dysfunction is dihydropyridines only. First line in bradycardia or atrioventricular block. Amlodipine is the alternative in decreased left ventricular function. | Hypotension, headache, flushing, peripheral edema. | Avoid short-acting agents (nifedipine). Contraindicated with systolic pressure below 100 mmHg. Avoid calcium channel blockers other than amlodipine in decreased left ventricular function. After a myocardial infarction the course table says to avoid calcium channel blockers (current practice allows a non-dihydropyridine when a beta blocker cannot be used). | Dizziness; monitor relief of symptoms. Cytochrome P450 3A4 (CYP3A4) interactions. | L8 slide 22 slide 20 slide 21 slide 23 slide 24 slide 34 |
| Non-dihydropyridine calcium channel blockers diltiazem, verapamil | Lower demand and help supply: mild dilation in areas of fixed stenosis and relief of vasospasm; act on the heart as well as the vessels. | Heart rate falls; contractility falls; systolic blood pressure falls; left ventricular volume unchanged or decreased. Moderate vasodilation (two plus); atrioventricular conduction falls (verapamil the most). | Initial therapy when beta blockers are contraindicated or not tolerated. Chosen (as a class) for vasospastic angina, asthma, severe peripheral vascular disease and uncontrolled diabetes (not for left ventricular dysfunction). First line in diabetes when there is no other reason for a beta blocker (course table; current practice also accepts a cardioselective beta blocker). Avoid in bradycardia or atrioventricular block. | Hypotension; slowed heart rate and atrioventricular conduction. | Contraindicated: systolic pressure below 100 mmHg, heart rate below 60, acute heart failure, ejection fraction below 40 percent. Caution with a concurrent beta blocker. After a myocardial infarction the course table says to avoid calcium channel blockers. | Monitor heart rate. Dizziness and constipation. Cytochrome P450 3A4 (CYP3A4) interactions. | L8 slide 22 slide 20 slide 21 slide 23 slide 24 slide 34 |
| Short-acting nitrates nitroglycerin sublingual tablet (Nitrostat) or lingual spray (Nitrolingual Pumpspray) | Nitric oxide raises cyclic guanosine monophosphate (cGMP), lowering cytosolic calcium: vasodilation. Supply: dilating coronary arteries, relief of vasospasm, antithrombotic and antiplatelet effects. | Heart rate rises; systolic blood pressure falls; left ventricular volume falls markedly (less preload). | Rescue: relieve acute symptoms and prevent effort-induced angina. Sublingual nitroglycerin for acute relief. | Hypotension (orthostatic), headache, reflex tachycardia. | Contraindicated: phosphodiesterase type 5 inhibitors (sildenafil, tadalafil, vardenafil) and hypotension. Avoid in severe aortic valve stenosis and obstructive cardiomyopathy. | Store in the original container in a cool, dry place; course rule: replace tablets 3–6 months after opening (current labeling uses the expiration date if kept in the tightly closed original glass container); apply or spray under the tongue; warn about orthostatic hypotension; call emergency medical services if there is no relief 5 minutes after the first dose. | L8 slide 27 slide 25 slide 26 slide 28 slide 33 slide 54 |
| Long-acting nitrates isosorbide mononitrate (Imdur), isosorbide dinitrate; nitroglycerin ointment and patch | Same nitric oxide and cyclic guanosine monophosphate mechanism as the short-acting forms: vasodilation, preload reduction and coronary dilation. | Same pattern as the short-acting nitrates: heart rate rises, systolic blood pressure falls, left ventricular volume falls markedly. | Usually an adjunct and not recommended as monotherapy; allowed as initial therapy when beta blockers and calcium channel blockers are contraindicated or not tolerated, otherwise added to them. Mononitrate lasts 12 hours (once daily); dinitrate 3–6 hours (three times daily). Useful in variant angina. | Headache, flushing, postural hypotension, reflex tachycardia; tolerance (tachyphylaxis). | Contraindicated: phosphodiesterase type 5 inhibitors. Avoid in severe aortic valve stenosis and obstructive cardiomyopathy. | Nitrate-free interval: patch or ointment 12 hours on, 12 hours off; wipe off the old ointment before applying the new one; keep covered with applicator paper. | L8 slide 29 slide 30 slide 31 slide 32 slide 33 slide 39 |
| ACE (angiotensin-converting enzyme) inhibitors vasculoprotective add-on | Not antianginal: do not significantly affect myocardial oxygen consumption; may help prevent progression of coronary artery disease. | No significant effect on oxygen consumption; do not relieve symptoms of angina. | For coronary artery disease with diabetes and/or left ventricular systolic dysfunction; indefinite use after myocardial infarction, left ventricular dysfunction or diabetes; consider in all patients with coronary artery disease or other vascular disease. | Adverse effects are covered in the antihypertensive drug chart. | Pregnancy contraindication is covered in the antihypertensive drug chart. | Long-term protection, not symptom relief. | L8 slide 35 |
| Aspirin and clopidogrel antiplatelet, vasculoprotective add-on | Antiplatelet: used to prevent acute coronary syndrome. | No heart rate, contractility or wall tension effect is listed; they are preventive, not antianginal. | Aspirin for all patients with ischemic heart disease in the absence of contraindications. Clopidogrel (as efficacious in secondary prevention) for patients allergic to aspirin. | Adverse effects of aspirin and clopidogrel are not covered here; aspirin contraindications are in the next column. | Aspirin: allergy, recent gastrointestinal bleed, recent intracranial hemorrhage. | Clopidogrel is the substitute when aspirin cannot be taken because of allergy. | L8 slide 37 slide 53 |