Ceftriaxone therapy of bacterial meningitis: cerebrospinal fluid concentrations and bactericidal activity after intramuscular injection in children treated with dexamethasone.

Antibiotic therapy is administered intravenously to children with bacterial meningitis to achieve the highest possible blood and cerebrospinal fluid (CSF) concentrations. However, intravenous access for the entire duration of therapy may be difficult in some children. Intramuscular therapy offers a more versatile option; however, CSF concentrations and bactericidal activity following im injection in children concurrently treated with dexamethasone have not been studied. We prospectively evaluated 37 children given an im dose of ceftriaxone on either the 3rd, 6th or 9th day of antibiotic therapy while receiving dexamethasone for the first 4 days of treatment. All children were required to have normal peripheral perfusion at the time of im injection. Four to 6 hours after im injection CSF was obtained. The average age of study patients was 28 months; Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae type b were responsible for 95% of all infections. All children studied had detectable CSF ceftriaxone concentrations, with mean (+/- SD) concentrations (microgram/ml) on Days 3, 6 and 9 of therapy of 5.7 +/- 5.5 (n = 12), 5.2 +/- 5.0 (n = 14) and 2.0 +/- 2.6 (n = 10), respectively. All CSF bactericidal titers for N. meningitidis, S. pneumoniae and H. influenzae type b, regardless of day of im injection, were > or = 1:64. Intramuscular ceftriaxone therapy of bacterial meningitis may be a reasonable therapeutic option for the convalescing child with good peripheral perfusion.