Laninamivir octanoate for post-exposure prophylaxis of influenza in household contacts: a randomized double blind placebo controlled trial.

Abstract

Laninamivir octanoate, a long-acting neuraminidase inhibitor, is an effective treatment for influenza. However, its effectiveness for the prevention of influenza has not yet been demonstrated. We conducted a double-blind, multicenter, randomized, placebo-controlled trial to determine whether laninamivir octanoate was superior to a placebo for post-exposure prophylaxis of influenza in household contacts. Eligible participants, who were household members who did not have influenza and were in contact with an influenza-infected index patient, were randomly assigned (1:1:1) to one of three groups: 20 mg of laninamivir octanoate once daily for 2 days (LO-2), 20 mg of laninamivir octanoate once daily for 3 days (LO-3), or a placebo. The primary endpoint was the proportion of participants who developed clinical influenza during a 10-day period. A total of 1711 participants were enrolled, and 1451 participants were included in the primary analysis. The proportion of participants with clinical influenza was 3.9 % (19/487) in the LO-2 group, 3.7 % (18/486) in the LO-3 group, and 16.9 % (81/478) in the placebo group (P < 0.001 for each of the laninamivir octanoate group). The relative risk reductions, compared with the placebo group, were 77.0 % [95 % confidence interval (CI) 62.7-85.8] and 78.1 % (95 % CI 64.1-86.7 %) for the LO-2 and LO-3 groups, respectively. The incidences of adverse events in the laninamivir octanoate groups were similar to that in the placebo group. The inhalation of 20 mg of laninamivir octanoate once daily for 2 or 3 days was well tolerated and effectively prevented the development of influenza in household contacts.

• Authors: Seizaburo Kashiwagi, Akira Watanabe, Hideyuki Ikematsu, Shinichiro Awamura, Takako Okamoto, Mitsutoshi Uemori, Katsuyasu Ishida
• Journal: Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy (J Infect Chemother) Vol. 19 Issue 4 Pg. 740-9 (Aug 2013) ISSN: 1437-7780 [Electronic] Netherlands
• PMID: 23732307 (Publication Type: Journal Article, Multicenter Study, Randomized Controlled Trial)

Chemical References

• Antiviral Agents
• Guanidines
• Placebos
• Pyrans
• Sialic Acids
• laninamivir
• Zanamivir

Topics

• Administration, Inhalation
• Adolescent
• Adult
• Antiviral Agents (adverse effects, therapeutic use)
• Child
• Child, Preschool
• Disease Transmission, Infectious (prevention & control)
• Double-Blind Method
• Family Characteristics
• Female
• Guanidines
• Humans
• Infant
• Influenza, Human (drug therapy, prevention & control, transmission)
• Male
• Middle Aged
• Placebos
• Post-Exposure Prophylaxis (methods)
• Pyrans
• Sialic Acids
• Zanamivir (adverse effects, analogs & derivatives, therapeutic use)