Almitrine bismesylate in congenital central hypoventilation.

We have carried out sequential studies of respiration and sleep state, from two weeks to two years of age in a girl with congenital central hypoventilation. When awake her minute ventilation (VE) and blood gases are normal, and when asleep she shows hypoventilation, with progressive hypoxia, hypercarbia and respiratory acidosis, most marked in NREM sleep. There has been no consistent change in VE (expressed as ml/kg/min) with age, awake or asleep, and she remains ventilator dependent when asleep. Growth and development are normal. We report a trial of almitrine bismesylate at the age of 21 months. A dose of 1.5 mg/kg/day orally for eight days produced minimal changes in VE, but when given 2.6 mg/kg/day for a further seven days there was a significant increase in VE in both NREM (27% increase) and in REM sleep (30% increase). These changes were accompanied by substantial improvements in blood gases, with PaCO2 less than 50 mmHg and PaO2 greater than 60 mmHg throughout a four hour study period asleep, off the ventilator, in air. After stopping almitrine bismesylate VE and blood gas values returned to pretreatment values. Almitrine bismesylate may be of value as an alternative to artificial ventilation in this condition.