Trimethoprim-sulfamethoxazole-induced refractory hypoglycaemia successfully treated with octreotide

Dose Dependent Effect of Sulfamethoxazole on Inhibiting KATP Channel of Mouse Pancreatic β Cell

Sulfamethoxazole (SMX) is widely used as an antibiotic in the clinical application with side effects of hypoglycemia. This is because SMX contains the sulfonamide structure, which closes ATP-sensitive potassium (KATP) channels and induces insulin secretion. However, there are no detail reports that measure the effective dose that can close KATP channels and induce insulin secretion. In this study, whole-cell patch clamp recording was utilized to measure the effect of SMX on KATP channel activity on pancreatic β cells. Also, the static incubation assay with mice islets was assessed to measure the insulin secretion capacity of SMX. SMX was shown to inhibit the KATP channel in pancreatic β cell membrane and induce insulin secretion in relatively high concentration. The half maximal inhibitory concentration (IC50) for KATP channel activity of SMX was .46 ± .08 mM. It was also shown that a near IC50 concentration of SMX (.5 mM) was able to nearly fully block the KATP channel when simultaneously applied with low concentration sulfonylurea, tolbutamide (.01 mM). Our present data provide important information for the clinical use of SMX to treat infection in diabetic patients using sulfonylureas.

Clinical features, risk factors, diagnosis, and treatment of trimethoprim-sulfamethoxazole-induced hypoglycemia

OBJECTIVE

Hypoglycemia is a sporadic and serious adverse reaction of trimethoprim-sulfamethoxazole (TMP-SMX) due to its sulfonylurea-like effect. This study explored the clinical characteristics, risk factors, treatment, and prognosis of TMP-SMX-induced hypoglycemia.

METHODS

Case reports and series of TMP-SMX-induced hypoglycemia were systematically searched using Chinese and English databases. Primary patient and clinical information were extracted for analysis.

RESULTS

A total of 34 patients were reported from 31 studies (16 males and 18 females). The patients had a median age of 64 years (range 0.4-91), and 75.8% had renal dysfunction. The median duration of a hypoglycemic episode was six days (range 1-20), and the median minimum glucose was 28.8 mg/dL (range 12-60). Thirty-two patients (97.0%) showed neuroglycopenic symptoms, with consciousness disturbance (30.3%) and seizure (24.2%), sweating (18.2%), confusion (15.2%), asthenia (12.1%) being the most common symptoms. Fifteen patients (44.1%) had elevated serum insulin levels, with a median of 31.8 μU/mL (range 3-115.3). C-peptide increased in 13 patients (38.2%), with a median of 7.7 ng/mL (range 2.2-20). Complete recovery from symptoms occurred in 88.2% of patients without sequelae. The duration of hypoglycemia symptoms was 8 hours to 47 days after the intervention. Interventions included discontinuation of TMP-SMX, intravenous glucose, glucagon, and octreotide.

CONCLUSION

Hypoglycemia is a rare and serious adverse effect of TMP-SMX. Physicians should be aware of this potential adverse effect, especially in patients with renal insufficiency, increased drug doses, and malnutrition.