Efficacies Compared for Laninamivir, Peramivir, Oseltamivir for Influenza

NEW ORLEANS, LA—Peramivir was superior to oseltamivir for the treatment of seasonal influenza, Yusuke Yoshino, MD, from Teikyo University School of Medicine, Tokyo, Japan, and colleagues concluded at IDWeek 2016.

Seasonal influenza is currently treated with a class of drugs known as neuraminidase inhibitors. These include oseltamivir, zanamivir, laninamivir, and peramivir. However, the clinical efficacies of peramivir and laninamivir, which are available in a limited number of countries, remain uncertain for seasonal influenza. Peramivir is the only drug administered intravenously, while laninamivir is inhaled. For each agent, treatment is usually completed using a single dose. 

Dr. Yoshino and colleagues conducted a randomized clinical trial (n=51) in patients who visited their outpatient clinic with seasonal influenza between November 2013 and March 2015. Patients were randomized to 1 of 3 treatment groups: oral oseltamivir 75mg twice daily for 5 days (n=17); inhaled laninamivir 40mg one dose (n=17); or IV peramivir 300mg one dose (n=17).

“Influenza was diagnosed on the basis of a positive result of influenza rapid antigen test, in the presence of signs and symptoms of influenza-like illness, including fever, muscle pain, chills, sweating, headache, dry cough, fatigue, nasal congestion, disorientation, hypotension, and respiratory failure, without other focal signs of infection,” Dr. Yoshino noted.

Demographic and clinical data were collected on the first visit, including body temperature, pulse rate, and type of influenza (A or B). 

“After treatment for influenza, the clinical course of the symptoms was evaluated by a questionnaire,” the study authors explained. “Patients who did not submit the questionnaire were excluded from the study.”

The primary study end point was time to defervescence following treatment with the neuraminidase inhibitors; the secondary end point was resolution of other symptoms.

A total of 34 patients were available for follow-up, 9 in the oseltamivir arm, 12 in the laninamivir arm, and 13 in the peramivir arm. Duration of fever on the first visit was similar; 24 hours in the oseltamivir arm, 28.1 hours in the laninamivir arm, and 24 hours in the oseltamivir arm, and no other significant differences in background data or symptoms at admission were noted.

Results showed that average time to defervescence was significantly shorter in the peramivir group, 24 hours, compared with the oseltamivir group, 64 hours (P=0.004). Although the laninamivir group had a shorter duration of fever (38 hours) than the oseltamivir group, this difference was not significant (P=0.151).

The investigators found “no significant difference among the 3 groups in terms of resolution of other symptoms after treatment.”

“Our study showed that peramivir was valuable in patients with seasonal influenza,” Dr. Yoshino noted. “The blood concentration of peramivir peaks immediately after IV administration; in addition, this route easily leads to high concentration of the drug in serum. This may explain the superiority of peramivir compared to oseltamivir for the treatment of seasonal influenza.”

The single-dose laninamivir might represent a clinical advantage over the multiple-dose oseltamivir with respect to medication adherence, the study authors concluded.