Respiratory alkalosis and metabolic acidosis in a child treated with sulthiame.

OBJECTIVE

To report on severe acid-base disturbance in a child with symptomatic epilepsy treated with sulthiame.

RESULTS

A 9.5-year-old boy with chronic generalized tonic-clonic seizures was treated with carbamazepine and valproic acid. Because of poor seizure control, sulthiame was added to the treatment. Two months later, he presented at the emergency department with severe weakness, headache, dizziness, dyspnea, anorexia, and confusional state. Arterial blood gas analysis showed mixed respiratory alkalosis with high anion gap metabolic acidosis. Sulthiame-induced acid-base disturbance was suspected. The drug was withheld for the first 24 hours and then restarted at a reduced dosage. The arterial blood gases gradually normalized, the confusion disappeared, and the patient was discharged home.Three months later, 4 weeks after an increase in sulthiame dosage, the patient was once again admitted with the same clinical picture. Improvement was noted after the drug dosage was reduced.

CONCLUSIONS

This is the first report of mixed respiratory alkalosis and metabolic acidosis in a child treated with sulthiame. Monitoring of the acid-base status should be considered in patients treated with sulthiame.