Severe hypoglycemia during pneumocystis pneumonia treatment associated with trimethoprim–sulfamethoxazole use in a patient on peritoneal dialysis

Abstract

Abstract Background Trimethoprim–sulfamethoxazole (TMP/SMX) is an essential antimicrobial agent for treating pneumocystis pneumonia (PCP). Furthermore, the risk of hypoglycemia is increased with the co-administration of sulfonylurea due to the presence of the same sulfanilamide structural group in SMX and sulfonylurea. However, hypoglycemia caused by a single administration of TMP/SMX is a rare adverse reaction, and not many cases have been reported. Renal failure is a risk factor for hypoglycemia with single TMP/SMX administration. Case presentation A 54-year-old Japanese woman on peritoneal dialysis (PD) for 10 years was admitted to our hospital for the suspicion of PCP. She underwent immunosuppressive treatment with oral prednisolone (3 mg/day) and a subcutaneous injection of adalimumab (40 mg) every 2 weeks for rheumatoid arthritis. We initiated the administration of a low-to-moderate dose of TMP/SMX (TMP equivalent to TMP/SMX, approximately 8 mg/kg/day) in the patient, considering that she was on PD. At 10 days after administration, the patient became unconscious, and blood test results showed that her blood glucose level was low (15 mg/dL). Unlike hypoglycemia, her serum insulin levels were abnormally high (69.4 μU/mL) at that time. Glucose injection was used for correcting the hypoglycemia, but it was refractory. Highly concentrated glucose infusion was needed to maintain her blood glucose level normal. Her serum insulin level was confirmed to have returned to normal (4.0 μU/mL) at 9 days after completing the TMP/SMX treatment. Conclusions We suspected that the refractory hypoglycemia in this case was caused by high levels of insulin secretion due to the accumulation of TMP/SMX. One of the risk factors in this patient was the low excretion rate of TMP/SMX into the PD fluid. Although hypoglycemia is a rare complication of TMP/SMX, we should consider this risk during TMP/SMX use in patients, especially those on PD.

Keywords

• Trimethoprim–sulfamethoxazole
• Hypoglycemia
• Pneumocystis pneumonia
• Peritoneal dialysis