Pharmacologic study of monohydrated caffeine in the treatment of apnoea of premature infant

Monohydrated caffeine was the only respiratory xanthine available in our country to treat apnea of premature infant. The aim of this study was to evaluate plasma levels of this molecule at dosages of 20 mg/kg (equal to 18 mg/kg of caffeine base) as a loading dose and 5 mg(-1) kg(-1) (equal to 4.5 mg(-1) kg(-1) of caffeine base) as a maintenance dose. The study was prospective including premature infants less than 34 weeks of gestational age born between the 1st of july 2001 and 15th december 2001 and receiving monohydrated caffeine to prevent apnea. Each premature infant has received orally a loading dose of 20 mg/kg in the first hours of life followed, 24 h after, by a maintenance dose orally once a day of 5 mg/kg until 35 weeks of post-conceptional age. Caffeinemia plasma levels were measured by high performance liquid chromatography immediately before the second dose to determine the loading residual rate and immediately before the sixth dose to determine the maintenance residual rate. Twenty-one premature infants were included. Their medium term was 31.4 weeks (27.4-33.3 weeks), birth weight was 1684 g (1000-2800 g) and sex-ratio M/F was 1.3. Fifteen infants (71.4%) have presented apnea with an average of 4.1 episodes per infant and per day. Tolerance of the medicament was good in all cases. The medium loading residual rate was 3.26 microg/ml (1.75-7.80) and the medium maintenance residual rate was 4.26 microg/ml (2.13-7.64). Prescribed at a dosage close to twice the recommendations of the literature, monohydrated caffeine does not provide efficient plasma rates. This is probably due to a difference in its oral bio-availability compared with caffeine citrate and further study with greater dosages is needed to appreciate its efficacy.