Comparing the Effect of Caffeine and Aminophylline on the Osteopenia of Prematurity in Neonates

Abstract

BACKGROUND: Methylxanthines produce renal effects such as diuresis and natriuresis. Premature neonates have increased urinary calcium excretion following treatment with methylxanthines for apnea. We compared the effect of two commonly used methylxanthines, caffeine and aminophylline, in the development of osteopenia of prematurity and phosphorus and alkaline phosphatase levels. METHODS: In a randomized clinical trial, 125 preterm infants with gestation age 32 weeks or less and birth weight less than 1500 grams with an indication for methyxanthine therapy were enrolled in the study. Group A (N=60) received aminophylline and group C (N=65) received caffeine. These drugs were started from the second day of birth until neonate was apnea free for 1 week or reached corrected gestation age of 34 weeks. Serum phosphorus and alkaline phosphatase levels were measured at 45 days of life as surrogate biomarkers for the osteopenia of prematurity. RESULTS: The mean gestation age and birth weight were 28.7 +/- 1.8 weeks and 1090 +/- 144 grams in group A and 28.7 +/- 2.0 weeks and 1042 +/- 170 grams in group C (P>0.05). Osteopenia of prematurity was diagnosed in 65 neonates (52%) of which 29 neonates (48.3%) were in aminophylline group and 36 patients (55.3%) in caffeine group (P=0.27). Bronchopulmonary dysplasia was detected in 53 neonates (42%) of which 21 (35%) were in group A and 32 (49.2%) were in group C (P=0.07). CONCLUSION: In our study, aminophylline and caffeine were similar with respect to the risk of osteopenia of prematurity in preterm infants.