Medications for Angina
Nitroglycerin
Resting, nitroglycerin tablets (placed under the tongue), and nitroglycerin sprays all relieve angina by reducing the heart muscle's demand for oxygen. Nitroglycerin also relieves spasm of the coronary arteries and can redistribute coronary artery blood flow to areas that need it most. Short-acting nitroglycerin can be repeated at five minute intervals. When 3 doses of nitroglycerin fail to relieve the angina, further medical attention is recommended. Short-acting nitroglycerin can also be used prior to exertion to prevent angina.
Longer-acting nitroglycerin preparations, such as Isordil tablets, Nitro-Dur transdermal systems (patch form), and Nitrol ointment are useful in preventing and reducing the frequency and intensity of episodes in patients with chronic angina. The use of nitroglycerin preparations may cause headaches and lightheadedness due to an excess lowering of blood pressure.
Beta Blockers
Beta blockers relieve angina by inhibiting the effect of adrenaline on the heart. Inhibiting adrenaline decreases the heart rate, lowers the blood pressure, and reduces the pumping force of the heart muscle, all of which reduce the heart muscle's demand for oxygen. Beta blockers include:
- acebutolol (Sectral)
- atenolol (Tenormin)
- bisoprolol (Zebeta)
- metoprolol (Lopressor, Lopressor LA, Toprol XL)
- nadolol (Corgard)
- propranolol (Inderal)
- timolol (Blocadren)
Side effects include:
- worsening of asthma,
- excess lowering of the heart rate and blood pressure,
- depression,
- fatigue,
- impotence,
- increased cholesterol levels, and
- shortness of breath due to diminished heart muscle function (congestive heart failure).
Calcium Channel Blockers
Calcium channel blockers relieve angina by lowering blood pressure, and reducing the pumping force of the heart muscle, thereby reducing muscle oxygen demand. Calcium channel blockers also relieve coronary artery spasm.
Calcium channel blockers include:
- amlodipine (Norvasc)
- bepridil (Vascor)
- diltiazem (Cardizem)
- felodipine (Plendil)
- isradipine (Dynacirc)
- nicardipine, (Cardene)
- nifedipine (Adalat, Procardia)
- nimodipine (Nimotop)
- nisoldipine (Sular)
- verapamil (Calan)
Side effects include:
- swelling of the legs,
- excess lowering of the heart rate and blood pressure, and
- depressing heart muscle function.
- Miscellaneous anti-anginal drugs
New drugs are being studied to treat angina. In 2006, the FDA approved ranolazine (Ranexa). Because of its side effects (potential to cause abnormal heart rhythm), ranolazine is indicated only after other conventional drug treatments are found to be ineffective.
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