COMPARISON OF THE EFFECTS OF THEOPHYLLINE AND CAFFEINE ON SERUM ERYTHROPOIETIN CONCENTRATION IN PREMATURE-INFANTS

Theophylline administration has been shown to attenuate erythropoietin (EP) production in adults: the effect of caffeine is not known. Our a im was to determine whether caffeine and theophylline had similar effe cts on EP production in the premature newborn. If caffeine was found t o have a greater effect, this would influence prescribing habits. Fift y preterm infants (mean gestational age 28 weeks) who had clinically s ignificant apnoea were randomized to receive theophylline (4 mg/kg the n 2 mg/kg twice daily) or caffeine (10 mg/kg then 2.5 mg/kg once daily ). The methylxanthines were contained at least until discharge from th e NICU and the dosage altered to keep the levels within the therapeuti c range. As an assessment of EP production, serum EP concentrations we re measured. Blood for EPI haemoglobin, reticulocyte count, theophylli ne and caffeine levels was obtained prior to treatment and at least du ring weeks 3 and 7. There was no significant difference in the mean EP level in the two groups taken prior to treatment at a median age of 2 days of life. There were similar falls in haematocrit and haemoglobin in the two groups during the study period compared to pre-treatnnent values. At that time, however, the median reticulocyte count was highe r in the caffeine compared to the theophylline treated infants (P < 0. 05). This was associated with a rise compared to baseline (median 10.0 -0.2 mU/ml) in the mean EP levels in the caffeine group and a decrease from a median of 10.1 to 8.3 mU/ml in the theophylline group, but the EP levels in the two groups at week 7 did not differ significantly. C onclusion These results suggest that caffeine does not have a greater impact than theophylline on EP production.