[Importance of monitoring theophylline and caffeine plasma levels in the management of neonatal apnea].

The simultaneous determination of caffeine and theophylline plasmatic levels has been proposed when the later is used in the treatment of the newborn's apnea. The caffeine plasmatic levels have been measured in five premature newborns treated with theophylline and the percentage of caffeine respect of theophylline, appraising its possible clinic repercusion. All the patients obtained theophylline levels into the therapeutic range proposed and a good efficacy was obtained without toxicity data, but there were a great interindividual variation in the amount of caffeine derived from theophylline (range from 12 to 50%). This result suggests the convenience of monitoring both drugs, especially when toxicity appear with theophylline levels into the therapeutic range.