NEW YORK (Reuters Health) – There’s guidance on the dosing of prophylactic oseltamivir for premature neonates exposed to H1N1 influenza, in a “Brief Report” in the Journal of Infectious Diseases for August 15, now available online.
Dr. Edward P. Acosta, with the University of Alabama at Birmingham School of Medicine, and colleagues note in their paper that although oseltamivir is approved for treating 2009 influenza A (H1N1) infection in infants at 3 mg/kg/dose twice daily, there are no data on dosing in premature infants.
The authors explain that the active metabolite of oseltamivir is cleared by the kidneys, and since preemies have underdeveloped renal function, they probably require a lower dosage than term infants.
Because it would be unethical to perform a dose-finding trial in otherwise healthy premature babies, the team had a protocol in place to collect pharmacokinetic data in multiple NICUs when exposure necessitated oseltamivir treatment or prophylaxis.
They describe a situation where an H1N1-infected healthcare worker exposed 32 preemies in the NICU, and “the treating neonatologist elected to administer oseltamivir prophylactically to these neonates at a scheduled dose of 1.5 mg/kg/dose twice daily for 10 days.” This dose was “an educated guess.” A single blood sample was collected from available babies after the fifth dose.
In the end, 20 of them were enrolled in the pharmacokinetic sampling study. The modeled results “suggest an oseltamivir dose of approximately 1.0 mg/kg/dose (twice daily) should achieve oseltamivir carboxylate exposures in premature neonates (<38 weeks) comparable to that in infants and young children receiving 3 mg/kg/dose twice daily,” Dr. Acosta and associates report.
They conclude, “These data provide initial oseltamivir dosing guidance in premature babies, which is vital to the global public health response” to H1N1 influenza.
Oseltamivir Dosing for Influenza Infection in Premature Neonates
J Infect Dis 2010;202.