Objective: To determine the half-life of serum caffeine concentrations and its relation to apnea of prematurity (AOP) after caffeine is discontinued in preparation for hospital discharge.
Study design: Prospective cohort study involving preterm infants with gestational ages ⩽33 weeks at birth. After caffeine was discontinued, serum caffeine concentrations and electronic detection of pathologic apnea, defined a priori, were obtained at 24 and 168 h, respectively.
Result: Caffeine levels decreased from 13.3±3.8 to 4.3±2 mg l(-1) (n=50, mean±s.d.) at 24 and 168 h, respectively (P<0.01). The mean caffeine half-life was 87±25 h at 35±1 weeks postmenstrual age. Seven days after discontinuation of caffeine, 64% of the infants had pathologic apnea.
Conclusion: Hospital discharge planning for preterm infants with a history of AOP should be carefully considered after discontinuing caffeine. This study showed that caffeine may not reach subtherapeutic levels until around 11-12 days.