Rational use of sulfonylureas.

The clinical use of sulfonylureas described in this article is both rational and effective for diabetic patients. Sulfonylureas are not used (1) in patients with insulin-dependent (type I) diabetes, because they are completely ineffective or (2) in patients with non-insulin-dependent (type II) diabetes who respond satisfactorily to diet, because they are unnecessary. In a patient with type II diabetes who has few or no symptoms but does not respond satisfactorily to diet, a sulfonylurea is introduced at a low dose, with gradual increases until a satisfactory response occurs, thus avoiding hypoglycemia. When symptoms of type II diabetes are marked, initiation of therapy with maximum doses of a sulfonylurea quickly distinguishes patients who need insulin therapy from those who have a good chance of responding to an oral drug. Abuse of sulfonylureas occurs when patients who could benefit from diet alone are treated with the drugs unnecessarily or, more often, when patients with poorly controlled disease continue to take maximum doses of the drugs. The usual situation is one in which the patient refuses insulin therapy or the physician does not suggest starting it. In other cases, the poorly controlled patient may be allowed to continue with a combination of a sulfonylurea and an ineffective dose of insulin. In this circumstance, the oral drug should be discontinued and insulin doses increased until control is more satisfactory. Because evidence is so compelling that near euglycemia has a beneficial effect on diabetic retinopathy, nephropathy, and neuropathy, physicians really do patients a disservice by misusing sulfonylureas.