In common cases, Nitroglycerin or Beta Blockers are given for CAD.
Several classes of medication are available if your physician chooses this therapy. One of the oldest is nitroglycerin or similar medications. These medications can be taken orally, under the tongue, or by patch or ointment on the skin. They reduce or prevent angina (chest pain) by lowering the blood pressure and filling pressure of the heart and by dilating (expanding) the heart arteries and helping balance oxygen supply and demand. These medications can only be used for 12-14 hours per day because the body does not respond to them if they are used continuously. They can cause headaches and light-headedness. There is no evidence that these medications prolong life.
The beta blockers (propranolol (Inderal)), atenolol (Tenormin), metoprolol (Lopressor), etc.) are another group of medications used to treat angina. These drugs reduce your symptoms by lowering the heart rate and blood pressure and by partially blocking the effects of epinephrine on the heart. In addition to reducing symptoms of CAD, they help prevent irregular heartbeats. For people who have had heart attacks, these drugs dramatically prolong life over the 3-5 years after the heart attack. Beta blockers may also prolong life in some people with congestive heart failure.
Beta blockers can give some people problems. People with type 1 diabetes who are prone to low blood glucose need to check more often because beta blockers can dull the body’s warning signs of low blood glucose. People with type 1 and type 2 diabetes may find that beta blockers upset their blood glucose control. The drugs may raise serum triglycerides while lowering HDL (good) cholesterol. They may make peripheral vascular disease worse. People with asthma or other forms of lung disease associated with wheezing may not be able to tolerate these drugs because they can make wheezing worse. Beta blockers may also slow the heart rate too much in patients who already have a low heart rate.
The third major class of drugs for angina are the calcium-channel blockers (nifedipine (Procardia), verapamil (Calan), diltiazem (Cardizem), amlodipine (Norvasc), etc.). These drugs treat angina by reducing blood pressure and dilating the coronary arteries. Some of these drugs also reduce heart beat rate. However, people with diabetes are advised not to use them because of serious side effects.