[The relatively frequent incidence of severe sulfonylurea-induced hypoglycemia in the last 25 years in Switzerland. Results of 2 surveys in Switzerland in 1969 and 1984].

In 1969 and 1984 all emergency wards in Switzerland were asked to report on the incidence of severe episodes of hypoglycemia (HE) during treatment with sulfonylureas. Each of the two surveys referred to a ten-year period (period A 1960-1969, period B 1975-1984). The number of HE reported was 78 for period A and 116 for period B. The number of diabetics treated with sulfonylurea preparations was established on the basis of tablet consumption, which amounted to 35,000 in period A and 47,500 in period B. The incidence of hypoglycemia in each period was comparable (period A 0.22, and period B 0.24 per 1000 patient years), but differed with regard to the sulfonylurea preparations used. In period A hypoglycemic episodes occurred more frequently under chlorpropamide than under tolbutamide and carbutamide. In period B the incidence of episodes under chlorpropamide and glibenclamide was comparable, but was significantly higher than under tolbutamide and glibornuride. The risk of hypoglycemia occurring is thus significantly higher under glibenclamide and chlorpropamide than under glibornuride and tolbutamide. 6.5% of HE were fatal in period A, compared with 4.3% in period B. Advanced age proved to be a risk factor in HE: 77% of patients with HE were over 69 years of age, whereas only 50% of all diabetics treated with sulfonylurea preparations were in this age group. Further risk factors were impaired renal function (21%) and possible drug interactions (27%). There was less likelihood of recurrence of a hypoglycemic episode in period B than in period A.(ABSTRACT TRUNCATED AT 250 WORDS)