Affiliations: Tahara Clinic, Yamaguchi, Japan | Fujita Health University School of Medicine, Aichi,
Japan | Research Center for Zoonosis Control, Hokkaido
University, Hokkaido, Japan | Department of Pediatrics, Eiju General Hospital,
Tokyo, Japan | Division for Clinical Trials, National Center for
Child Health and Development, Tokyo, Japan | Department of Pediatrics, Kagawa University, Kagawa,
Japan
Abstract: The aim of this study was to investigate the treatment of influenza
and safety of oseltamivir in infants less than 1 year of age. All-patient
surveillance was conducted using centralized enrolment at 219 medical
institutions. Safety data were collected for 1,663 patients less than 1 year of
age who developed influenza during the 2004–2005 influenza season. Patients
were stratified into three groups: patients not treated with a drug (Group A),
patients treated with oseltamivir (Group B), and patients treated with a drug
other than an antiviral agent (Group C). Significant differences (P = 0.0074, P
< 0.0001) were observed among incidences of adverse events in the three
groups (Group A: 26.7%, Group B: 30.0%, Group C: 21.5%) and between the
incidences of adverse drug reactions (ADRs) in the two drug-treated groups
(Group B: 6.7%, Group C: 0.9%). The most commonly reported ADRs in patients
treated with oseltamivir were diarrhoea, hypothermia, vomiting, and rash. We
found that 77.2% of patients received oseltamivir and 20.0% received
symptomatic treatments such as antipyretic agents. In infants less than 1 year
of age, incidence of ADRs with oseltamivir treatment was higher than with
symptomatic treatments, however these ADRs were treatable symptoms and
consistent with the ADRs reported in young children treated with oseltamivir.
Our analysis of the safety of oseltamivir in infants less than 1 year of age
revealed clinical acceptance of safety issues.
Keywords: Infant, under one year old, oseltamivir, influenza virus, drug safety
