L-leucine in secondary sulfonylurea failure

Ten diabetic patients, secondary failures to sulfonylureas, seven of whom were receiving maximal doses of tolbutamide and three of chlorpropamide, were concurrently given L-leucine, as tablets, in a daily dosage of 12 gm. for four to eight weeks. Good diabetic control, with most blood glucose values below 130 mg. per 100 ml., was achieved in three; a good response, as indicated by a fall in blood glucose values of 20 per cent or more, occurred in eight; two patients did not respond. Of four patients receiving thiazide, which might have contributed to their secondary failure, three responded. Reversal of osmotic diuresis and symptoms of nocturia occurred in five patients. No untoward effects of any significance were noted. Adjunctive use of L-leucine for better diabetic control in patients who have become refractory to sulfonylureas, or are receiving thiazides, is suggested.