AbstractIntroduction: Bioavailability of a drug is altered in paediatric age group especially due to many variable factors, like, larger body surface in proportion to body-wt., changes in hematocrit values and phases of maturation of organs like kidney, liver etc. Hence clinical response, to a drug would depend on verities of factors and, would decide the ultimate outcome in, especially, a sick child. Though introduction of newer antibiotic has led to control of infection to a larger extent in western countries, even there, neonatal infections, in particular, meningitis has proved to be difficult to treat, and this is probably due to altered pharmaco-kinetics in new born and small infants. Aims and Objectives: A Study of Theuraptic Response to Gentamycin on CSF of the Pediatric patients with Meningitis. Methodology: This was prospective clinical trial at tertiary care hospitalthe children admitted in pediatric ward of a general hospital constituted the material for the present study. Only those children, for whom diagnostic L.P. was considered necessary on admission, were included in this study and hence no child was subjected to L.P. only for the purpose of this study. Out of the selected children, those who did not have any clinical and laboratory evidence of intracranial infections, constituted the group of normal children. Whereas those, who had clinical and Laboratory evidence of intracranial infections, constituted the another group under study. Both the group of children was subjected for similar work-up. Total 28 children were included into the study. Result: The ratio of S1 ½ to C1 ½ varies mostly from 1.8:1 to 1:1, only one child showed lower concentration of drug in C.S.F. with ratio of 4:1 and another child had no detectable levels of drug in C.S.F. There was no correlation between the cell count in c.s.f. and ratio of s1 ½ to c1 ½. No. of children analyzed -12, Male – 7, Female - 5, There are wide fluctuations is the serum concentration at 1_1/2 hrs. C.S.F. did not show any detectable concentration of drug. Conclusion: It may be necessary to monitor serum concentration in such a way that minimal concentration be achieved to produce maximum therapeutic response without any risk of side effects.

Keywords: Gentamycin, CSF, Pediatric Meningitis.