Diabetes mellitus treated with chlorpropamide and tolbutamide. A four-year clinical study

The findings in 676 patients treated with tolbutamide and chlorpropamide for periods of up to four years are presented. Only small differences between the results obtained with the two drugs were found. In twenty patients treatment was discontinued because of intercurrent disease or because of side effects. There were sixty-seven primary failures (10 per cent). Of the remaining 589, there were sixty-six secondary failures (11 per cent), fifty-eight achieved fair control (10 per cent) and 465 good control (79 per cent). Satisfactory results were obtained most often in patients weighing between 85 per cent and 115 per cent of their standard weight, in those over forty-five years of age, and in those who had not previously required insulin. The mean body weight of the patients increased by 1.3 per cent while they were receiving sulfonylureas. Needle core liver biopsies were obtained from eight patients. Four of these were normal, three showed focal collections of chronic inflammatory cells, and one showed early portal cirrhosis.

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.

Blood sugar lowering effects of chlorpropamide and tolbutamide. A double blind cooperative study

Hypoglycemic and other effects of tolbutamide, chlorpropamide and placebo administration have been studied in 121 ketoacidosis-resistant diabetic males selected from an initial group of 3,493 patients in eleven Veterans Administration hospitals. A randomized double-blind technic of drug administration was employed. The effects of the drugs on fasting blood sugar (FBS) levels were determined and analyzed statistically. The administration of placebo produced a satisfactory fall in FBS levels in 26 per cent of the patients when used as the initial medication. Tolbutamide was successful in 60 per cent of the trials and chlorpropamide in 83 per cent. When a patient failed to respond to one sulfonylurea drug, he was tried on the other. Under these circumstances, chlorpropamide was more often effective than tolbutamide. Its greater effectiveness was further confirmed by the fact that, compared to tolbutamide, fewer patients required the maximal dosage of chlorpropamide. Primary drug failure with each of these sulfonylurea drugs was 16 per cent. There was no correlation between response and either pretreatment FBS levels or blood drug levels. Blood drug levels were higher for chlorpropamide than for tolbutamide at all levels of dosage. Toxic reactions occurred in less than 3 per cent of the patients, all on chlorpropamide. Secondary failures occurred in less than 10 per cent of the patients. Both of the sulfonylurea drugs studied are effective hypoglycemic agents. The hypoglycemic effect of placebo in one-fourth of the trials necessitates its inclusion in any study of the effectiveness of a therapeutic agent.