WASHINGTON — The benefits of oseltamivir aren't limited to treating and preventing influenza, Beth L. Nordstrom, Ph.D., reported in a poster presentation at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
Oseltamivir (Tamiflu) is indicated for the treatment of influenza in patients aged 1 year and older who have been symptomatic for no more than 2 days, and for prophylaxis of influenza in persons aged 13 years and older.
New data suggest that the drug also reduces the risk of pneumonia in all age groups, and the rates of antibiotic use and hospitalization in the oldest and youngest patients, said Dr. Nordstrom, of Ingenix Epidemiology, Auburndale, Mass.
In a retrospective cohort study sponsored by Hoffmann-La Roche, claims data from a large U.S. insurer containing a diagnosis of influenza from Dec. 1, 1999, through March 31, 2002, were analyzed.
Patients of all ages who had received oseltamivir were at significantly lower risk for pneumonia, particularly the oldest and youngest age groups. Among children aged 1-12 years, the proportion with a diagnosis of pneumonia was 0.7% among the 586 for whom oseltamivir was dispensed on the day of influenza diagnosis, compared with 2.5% of the 17,886 who did not receive oseltamivir, a 66% risk reduction.
In patients aged 13-59, pneumonia was diagnosed in 1.3% of the 10,649 who received the drug, compared with 2.1% of the 41,007 who did not—a reduction of 19%. In adults aged 60 and older, the difference was 1.7% of 463 with oseltamivir versus 8.8% of 3,298 without, a 59% drop.
The impact of oseltamivir on antibiotic dispensing and hospitalization was also greater in the youngest and oldest age groups. Antibiotic use dropped with oseltamivir by 30% in the 1- to 12-year-olds, by 9% in the 13- to 59-year-olds, and by 14% in the 60-plus group. Hospitalizations were reduced by 71% with oseltamivir in the 1- to 12-year-olds, by 25% in the 13- to 59-year age group and 45% in the 60-plus patients, Dr. Nordstrom reported.