Ampicillin in Haemophilus influenzae meningitis. Clinicopharmacologic evaluation of intramuscular vs intravenous administration
H. D. Wilson and K. C. Haltalin
Sixty-two children with Haemophilus meningitis were treated with ampicillin
sodium, 200 mg/kg/day for ten days. Thirty-one received the drug
intravenously (IV) for ten days; the other 31 patients received ampicillin
IV for five days (except for one test dose given intramuscularly [IM] on
day 2) followed by IM administration of ampicillin the last five days.
Ampicillin concentrations in cerebrospinal fluid (SCF) were higher one hour
after IV administration, but at two and four hours, concentrations were
greater after IM doses. Responses to therapy and rates of complications
were similar in the two groups. Fourteen patients had positive CSF cultures
on day 2. Ten of these were isolated only on Levinthal medium and would
have been overlooked with routine culture methods. All organisms were
ampicillin-susceptible and all CSF cultures were negative by 48 hours. More
patients with delayed sterilization had neurologic sequelae (78%) than
patients with prompt CSF sterilization (13%). The schedule of five days of
IV treatment followed by five days of IM therapy was pharmacologically and
clinically as effective as ten days of IV therapy and has practical
advantages.
