Chlorpropamide overdosage: delayed and prolonged hypoglycemia

Toxic emergencies of endocrine and metabolic therapeutic agents

Treatment recommendations for insulin, sulfonylurea, and thyroid hormone poisoning are widely divergent. Recent research data indicates a standard approach to management of these poisonings. Clinical practice may now incorporate recent findings.

Association of hyperinsulinemia with chlorpropamide toxicity

Clinical and metabolic features of chlorpropamide toxicity are described in two patients with diabetes mellitus and accidental chlorpropamide overdosage. Elevated serum insulin levels were found during hypoglycemia in both patients. The world's literature was reviewed for other cases of chlorpropamide toxicity in which insulin levels have been measured during hypoglycemia. A consistent feature of chlorpropamide toxicity is hyperinsulinemia. It is concluded that stimulation of the pancreatic beta cells during chlorpropamide toxicity leads to hyperinsulinemia and hypoglycemia.

Chlorpropamide overdose in renal failure: management with charcoal hemoperfusion

A potentially lethal chlorpropamide overdose in a patient with chronic renal failure on long-term hemodialysis was treated by two courses of charcoal hemoperfusion. Hemoperfusion shortened the half-life clearance of the drug from a mean value of 93.6 to 3.4 hours. Calculation of the fractional extraction indicated that hemoperfusion reduced the body burden of the drug by 24% and 19% (mean values) during the first and second hours of treatment, respectively. We conclude that charcoal hemoperfusion should be considered a definitive therapeutic option in such cases.

Duration of hypoglycemia and need for intravenous glucose following intentional overdoses of insulin

To assess the treatment of intentional insulin overdoses with intravenous (IV) glucose, we reviewed the records of 17 attempts in 15 patients seen during a ten-year period. The mean age of our patients was 29 +/- 9 years, and the mean overdose of insulin was 386 +/- 276 units. Eight patients were insulin-dependent diabetics and seven patients had no history of diabetes. We found that the nondiabetics were more likely to present with hypoglycemia (serum glucose less than 50 mg/dL) and develop recurrent hypoglycemia, despite oral intake and IV glucose infusion, than were diabetic patients (P less than .05, Fisher's exact test). We also found a significant relation (P less than .01) between the amount of insulin taken as a single overdose and either the total amount of IV glucose administered or the total time of IV glucose treatment until the hypoglycemic effects of excess insulin had resolved (glucose [g] = 52 + (.699) (dose U), R = .929 and time [h] = 10.5 + (.028) (dose U), R = .817). No patient sustained permanent complications from hypoglycemia. We conclude that prolonged, aggressive IV glucose infusion and serial monitoring of serum glucose levels is required in insulin overdoses. These patients may become hypoglycemic much later than predicted from the conventional duration of action of the various insulin preparations.

Diabinese-Dialume: a potential catastrophe

An oral hypoglycemic drug (Diabinese-chlorpropamide) was given inadvertently to a nondiabetic with renal insufficiency instead of the prescribed phosphate binder (Dialume-aluminum hydroxide). It was determined from this situation that hemodialysis is of no benefit in removing the drug from serum; the hypoglycemic effect of chlorpropamide is profound in nondiabetics, and the duration of therapy with dextrose infusions can be quite prolonged. We provide recommendations regarding therapy, bedside glucose monitoring, and prevention.

Suicidal overdoses with hypoglycemic agents

Suicide attempts using hypoglycemic agents are uncommon but are associated with a high level of morbidity and mortality. Their recognition is sometimes difficult and the duration of hypoglycemic effect is often prolonged. Two cases that illustrate the difficulties encountered in recognition and therapy are described. Effective therapy depends on adequate glucose supplementation to maintain euglycemia. Therapeutic intervention often must be maintained for several days. Glucocorticoids may be useful in difficult cases. Other modes of therapy, including glucagon, are unproven or controversial.

Intramuscular or intravenous glucagon for sulphonylurea hypoglycaemia?

Because of the differing opinions on the value of glucagon and the best way of administering it in severe hypoglycaemia induced by sulphonylurea drugs, experiments were conducted on normal subjects, and in diabetic patients before and during treatment with chlorpropamide. In all subjects glucagon raised blood sugar concentrations, and produced a greater and more prolonged increase in blood glucose concentrations when given intramuscularly than when given intravenously. Hypoglycaemia did not occur in any subject.

Chlorpropamide-induced hypoglycemia: successful treatment with diazoxide

A healthy adolescent boy was treated on two occasions for an overdose of chlorpropamide (Diabinese). Glucose therapy alone was not sufficient to control the hypoglycemia, but the administration of glucose plus diazoxide raised the blood sugar to supranormal levels. A bolus of intravenous glucagon briefly raised the blood sugar level to within normal limits, increased the blood ketones but also augmented insulin secretion. An overdose of sulfonylurea may cause prolonged and fatal hypoglycemia. Rational therapy, both in diabetic and normal persons, is glucose plus an "insulin antagonist." The administration of diazoxide was effective in our patient, substantially reducing the plasma insulin level; this agent may be the "insulin-antagonist" of choice for use in sulfonylurea-induced hypoglycemia.