Diabetologists in Doddabommasandra, Bangalore • Nitrates These useful drugs may be given in combination with beta-blockers or other anti-anginal treatment. There are a number of rapidly acting forms that can be used by a patient to obtain rapid relief of angina. In tablet form they dissolve rapidly under the tongue and should relieve angina within a few minutes. Anginine, which is available over the counter, can be broken in half. This may be useful for patients who experience side effects with a full tablet. However, they have a limited shelf-life (about three months once opened). Isordil is a similarly effective drug that lasts some years but is too small to be broken in half. There is also a prescription-only form available as a spray for sublingual use. It has a long shelf-life and is found by some patients to work a little more quickly than the tablets. These drugs may also be used prophylactically by those able to predict the onset of symptoms. Patients may need to be reassured that nitrates are not painkillers but relieve angina by helping the heart (by reducing myocardial wall stress). Patients must also be told that an increasing need for nitrates suggests a change in the severity of their angina and that their doctor should be informed of this. Response to sublingual nitrates may be helpful for diagnosis of chest pain. Rapid relief (within a few minutes) is suggestive of angina, but slower relief less so. Oesophageal spasm may also, however, be relieved by nitrates. Long-acting nitrates are readily available and are a useful adjunct to the treatment of angina. Nitrate patches have the advantage that the patient can place the patch close to the heart on the chest wall. This may have a reassuring feel about it. In fact they are equally effective placed anywhere on non-hairy skin. Because tolerance to nitrates develops and dissipates within hours, there should be a period of eight hours when the patient is not exposed to them (a nitrate-free interval). Usually the patient is advised to remove the patch before going to bed. If, however, the angina is usually worse at night, putting the patch on before bed and removing it during the following day may be the best approach. Oral long-acting nitrates are similarly effective. They are designed to ‘run out’ after 16 hours or so and therefore have a built-in nitrate-free interval. For this reason, they should be used only once a day. Nitrates have the advantage that larger doses give further therapeutic benefit as long as side effects are not intolerable. A dose of 120 mg or even more isorbide mononitrate or equivalent may be given daily. Nitrate side effects relate mostly to their vasodilator action. Headache is the most common problem and patients must be warned of this. If the patient persists with the drug and uses simple analgesics for the headache, tolerance usually develops after a few days. The drugs are best introduced at low doses; a small patch or half an isorbide mononitrate tablet. Nitrates do not impair ventricular function and the dose is not limited by this in the way that beta-blockers and calcium antagonists are. The short-acting nitrates can also cause headache and sometimes postural hypotension. Patients should be warned to sit down when using them. The patches can cause skin irritation in some patients.