Antianginals are drugs used to treat angina. They’re classified by how they reduce myocardial oxygen demand and/or improve oxygen supply.
Nitrates: Nitrates dilate coronary blood vessels and reduce the work of the heart, which lowers cardiac oxygen demand. Examples include nitroglycerine (GoNitro, Minitran, Nitro-Bid, Nitrostat, Nitromist) and isosorbide (Isordil, Dilatrate-SR, IsoDitrate).
For rapid relief, nitroglycerine is available as sublingual tablets and a spray.
Adverse effects include headache and dizziness.
Nitrates are contraindicated with phosphodiesterase inhibitors like sildenafil (Viagra) and tadalafil (Cialis). They should not be used in people with certain types of glaucoma.
Calcium channel blockers: These were discussed earlier under antihypertensives. Diltiazem (Cardizem, Tiazac) and verapamil (Calan, Verelan) are calcium channel blockers with antianginal properties.
Beta blockers: These were discussed earlier under antihypertensives. Cardioselective beta blockers like atenolol (Tenormin) and metoprolol (Lopressor, Toprol XL) are preferred as antianginals.
Ranolazine: Ranolazine (Ranexa, Aspruzyo Sprinkle) is a sodium channel blocker. Adverse effects include dizziness, edema, tinnitus, and vertigo.
Dipyridamole: Dipyridamole (Persantine) is a phosphodiesterase inhibitor used as an antianginal and antiplatelet agent.
Antiarrhythmics are drugs used to prevent and treat irregular cardiac rhythms (arrhythmias), such as atrial fibrillation and ventricular tachycardia. Some antiarrhythmics are also used as antihypertensives and antianginals. They’re classified by mechanism of action as follows.
Class I or Sodium channel blockers: This group includes flecainide (Tambocor), quinidine (Cardioquin, Cin-Quin, and Quinidex), and mexiletine (Mexitil). Adverse effects include worsening of arrhythmias, and cinchonism, which presents as nausea, tinnitus, and visual changes seen with quinidine and lupus-like syndrome with procainamide.
Class II or beta blockers: This group includes atenolol (Tenormin), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), propranolol (Inderal), and acebutolol (Sectral). Adverse effects include bronchospasm, fatigue, bradycardia, and depression.
Class III or potassium channel blockers: This group includes amiodarone (Cordarone, Pacerone), sotalol (Betapace, Sorine), ibutilide (Corvert) and dofetilide (Tikosyn). Adverse effects include prolongation of QTc, Torsades de Pointes, fatigue and dizziness. Amiodarone can cause dysfunction of the thyroid gland like hypothyroidism or hyperthyroidism, lung and liver damage.
Class IV or calcium channel blockers: They include verapamil (Verelan, Calan) and diltiazem (Cardizem, Tiazac). Adverse effects include hypotension, edema, constipation, headache and atrioventricular or AV conduction block.
Others: These drugs have unique mechanisms of action.
Lipids are fatty substances found in blood, fat cells, and cell membranes. The liver plays a major role in lipid metabolism. Cholesterol and triglycerides are types of lipids.
Elevated cholesterol and/or triglyceride levels are associated with cardiovascular and pancreatic diseases. Several classes of lipid-lowering drugs are available, and statins are the most commonly used.
Statins: Statins decrease cholesterol synthesis by inhibiting the rate-limiting enzyme, HMG CoA reductase. Examples include atorvastatin (Lipitor), rosuvastatin (Crestor), simvastatin (Zocor), and lovastatin (Mevacor).
Statins:
Adverse effects include myalgia, rhabdomyolysis, hepatotoxicity, and elevated liver enzymes. Rhabdomyolysis is the breakdown of muscle tissue, and in serious cases, it may cause renal failure.
When statins are taken together with macrolide antibiotics, the risk of serious adverse effects is higher because macrolides slow down statin metabolism, leading to higher statin levels in the blood.
The FDA recommends discontinuing statins in pregnant women because they can potentially cause fetal damage.
Fibrates: They decrease triglyceride levels. Examples include gemfibrozil (Lopid), fenofibrate (Lofibra, Antara) and fenofibric acid (Fibricor). Adverse effects include muscle pain and gallstones.
Niacin: Niacin is vitamin B3. It decreases triglyceride and cholesterol levels by decreasing the synthesis of fatty acids. Adverse effects include skin flushing, hypotension, and rash. Common brand names include Niacor and Niaspan.
Ezetimibe: It decreases the absorption of cholesterol from the intestine. A commonly available brand is Zetia. It’s often given in combination with a statin, e.g. simvastatin plus ezetimibe (Vytorin). Adverse effects include elevated liver enzymes and diarrhea.
Bile acid sequestrants: They prevent enterohepatic recycling of bile acids, which leads to decreased serum cholesterol levels. Examples include cholestyramine (Locholest, Prevalite, Questran), colestipol (Colestid) and colesevelam (WelChol).
Adverse effects include nausea, gastrointestinal upset and decreased absorption of drugs and fat soluble vitamins. Medications should be taken an hour earlier or 4-6 hours after taking bile acid sequestrants to prevent interference with drug absorption.
PCSK9 inhibitors: They are relatively new medications that decrease LDL cholesterol levels. Examples include evolocumab (Repatha) and alirocumab (Praluent). Adverse effects include dementia and muscle pain.
Fish oil supplements: Omega 3 fatty acids, sold as fish oil supplements, have shown some benefit in decreasing triglyceride levels by reducing synthesis, but they can increase LDL cholesterol in some patients. Taking very high doses may cause bleeding and stroke.
They can interact with anticoagulants and antiplatelets and increase the risk of bleeding. They have a synergistic effect in lowering blood pressure with antihypertensives.
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