Medications in the Treatment of Angina Drugs can be used for short-term relief of angina symptoms and for long-term treatment to slow or halt the progression of coronary heart disease (CHD). Nitrates These drugs dilate both arteries and veins. Dilation of the coronary arteries increases blood flow to the heart. Dilation of peripheral veins causes pooling of blood in the peripheral circulation. Because the heart then has to pump less blood, its workload and need for oxygen are reduced. Tablets of nitroglycerin, placed under the tongue during an attack of angina, generally bring relief within two to three minutes. If five minutes pass without a change in symptoms, a second dose may be taken. Typical doses range from 0.3 to 0.6 milligrams. Patients may experience headaches when first starting on nitrates, but these symptoms tend to diminish after a week or two. Sublingual nitroglycerin may also prevent angina when taken shortly before beginning activities likely to provoke chest pain. Longer-acting nitrate tablets and transdermal patches, pastes or ointments applied to the skin can provide longer protection against the onset of angina, although tolerance may develop. It is generally recommended that longer-acting nitrates be discontinued for four to six hours each day to prevent loss of their effectiveness. The longer and more frequently these nitrates are used, the less likely they are to relieve angina. Regular, long-term users often become resistant to the drug's effects. Beta-blockers These drugs control angina by slowing the heart rate and its force of contraction, thereby decreasing the heart's workload and oxygen consumption. Beta-blockers are often prescribed to help prevent a second heart attack. Calcium channel blockers Like nitrates and beta-blockers, calcium channel blockers reduce the heart's workload, allow more blood to flow through the coronary arteries, and decrease the oxygen requirements of the heart muscle. These drugs also alleviate angina by relieving coronary artery spasm (when this is the cause of the angina). However, only the long-acting forms should be used. Combination therapy In some people, neither beta-blockers nor calcium channel blockers alone provide sufficient relief of angina. One study found that combining both types of drugs significantly lengthened the time patients could exercise before experiencing angina. Last Updated: 2/19/2003 The Johns Hopkins University 1996-2003.  All rights reserved.  This information is not intended to provide advice on personal medical matters, nor is it intended to be a substitute for consultation.