Metabolic effects of beta-sympathomimetic drugs and dexamethasone in normal and diabetic pregnancy.

Marked hyperglycaemia and hyperinsulinaemia were observed in two normal women in premature labour treated with an intravenous infusion of a beta-sympathomimetic drug and intramuscular dexamethasone injections. Similar therapy in a chemical diabetic patient caused diabetic ketoacidosis, while treatment of an insulin dependent diabetic with dexamethasone alone resulted in a major increase in her insulin requirements. It is suggested that the diabetogenic effects of beta-sympathomimetic drugs and dexamethasone may be additive and that regular plasma glucose estimations should be made when they are used, especially in patients with impaired glucose tolerance.