VITAMIN-K1 CONCENTRATION IN BREAST-FED NEONATES AFTER ORAL OR INTRAMUSCULAR ADMINISTRATION OF A SINGLE-DOSE OF A NEW MIXED-MICELLAR PREPARATION OF PHYLLOQUINONE

The plasma disposition of a new mixed-micellar preparation (KONAKION M M, Roche) of phylloquinone (vitamin K1) has been studied in 25 healthy , fully breast-fed, newborn babies, randomized to receive a single dos e of either 1.5 mg i.m. (11 babies) or 3 mg p.o. (14 babies). Venous b lood samples were collected at 25 h, 4 days, and 24 days. After p.o. a dministration, the median plasma phylloquinone concentration increased to 89 ng/ml after 24 h, then decreased to 51 ng/ml after 4 days; the respective concentrations after i.m. injection were 146 ng/ml and 34 n g/ml. The higher plasma phylloquinone level in the i.m. group after 24 h was not statistically significant compared with that of the p.o. gr oup, but the reversed higher concentration in the p.o. group after 4 d ays was significant (p < 0.01). After 24 days the median plasma phyllo quinone had decreased to 0.44 ng/ml (range 0.19-1.44) and 1.05 ng/ml ( range 0.37-1.87) in the p.o. and i.m. groups, respectively. There was a significant difference between these plasma concentrations (p < 0.01 ). They were within or above the reference adult fasting range (0. 174 .68 ng/ml). The narrow range of plasma concentrations at 24 h and 4 da ys suggests a greater consistency of absorption from this micellar pre paration than from other emulsion-based preparations. Further studies are required to assess the long-term protection of a single oral dose against late hemorrhagic disease of the new-born. Until such time, bre ast-fed babies given this preparation orally should receive (an) addit ional dose(s) .