CLINICAL EVALUATION OF FORMAMIDINYLIMINOUREA, A NEW BIGUANIDE ORAL BLOOD SUGAR LOWERING COMPOUND: COMPARISON WITH OTHER HYPOGLYCEMIC AGENTS

Abstract

Studies with phenethylbiguanide (DBI) and three related analogs have demonstrated a definite blood sugar lowering action by this drug when ingested orally. This effect is found in a large variety of diabetics including types not hitherto affected by other oral blood-sugar lowering compounds. A review of earlier compounds such as guanidine and synthalin suggests that there are many parallels and differences with these newer substances. The mechanism of action of the biguanides, while not definite, is thought to be due to either or both (1) increase in anaerobic glycolysis (2) increased peripheral utilization of glucose. Of a study group of 173 patients including 53 juvenile-onset cases, 88% showed demonstrably lowered blood sugar levels although 38% were unable to continue therapy because of gastrointestinal side effects, which included anorexia, nausea, vomiting, metallic taste and occasionally diarrhea. These side effects were rapidly reversed on discontinuing or lowering the dose of the drug. Of the total group 107 were classified as "successful" and 82 still continue biguanide therapy, 57 without, and 25 with smaller (reduced) supplemental doses of insulin. Hepatic, renal and hematologic studies have revealed no abnormalities. Therefore, while this new non-sulfonylurea agent shows a capacity to lower blood sugar levels and does have a relatively high incidence of reversible side-effects, there has been no evidence of toxicity to date.