[Monitoring of phenobarbital use during the neonatal period by means of urinalysis]

Monitoring of blood barbiturate level was performed in 32 term newborns, who received 6 mg/Kg/die phenobarbital (PB), by assaying blood and urine samples. Cases were grouped according to duration of treatment which varied following multiples of 12 hours from 16 to 100 hours. Serum and urine PB assay was conducted through immunological percentage nephelometric inhibition. Plasma and urine PB levels within each group were significantly correlated (r = 0.8826; p less than 0.001), indicating that, if PB treatment is given without variations in dosage and if diuresis is not impaired, blood barbiturate level may be monitored through urine assays.