Conditions: Influenza
Keywords: randomized blinded controlled efficacy
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 194
Healthy volunteers: no

Brief summary:
This study is a randomized, blinded, placebo-controlled clinical efficacy trial to assess the duration and severity of influenza symptoms, and duration of viral shedding, in influenza patients receiving oseltamivir early and late relative to placebo.

There are two main hypotheses in this study:

1. The duration of influenza symptoms, mean severity score, and duration of viral shedding are reduced in patients who initiate oseltamivir treatment late (48 to 119 hours) compared to those receiving no antiviral therapy.
2. Prior influenza vaccination (same season) reduces the duration of influenza symptoms and mean symptom severity in patients receiving oseltamivir after adjusting for age and timing of antiviral therapy (early versus late).

There are two secondary hypotheses:

1. The duration of influenza symptoms, mean severity score, and duration of viral shedding are reduced in patients with influenza who initiate oseltamivir treatment early (\< 48 hours) versus late (48 to 119 hours).
2. The incidence of secondary complications is lower in patients initiating oseltamivir therapy late relative to those receiving no antiviral therapy.

Detailed description:
In the past decade influenza has become increasingly recognized as a serious disease and pandemic threat. Elderly persons, young children, and individuals with chronic medical conditions have the greatest risk for complications or death from influenza infection. Neuraminidase inhibitors are currently licensed for the treatment and prevention of influenza if started early in the course of illness, but little is known regarding the effects of oseltamivir (one neuraminidase inhibitor) on illness severity when initiated later in the course of illness. Greater knowledge of the treatment effects is urgently needed for optimal management of seasonal influenza, and to maximize use of a limited stockpile of antiviral drugs in the event of an influenza pandemic.

Arms:
arm 1: Adults and adolescents weighing greater than 88 pounds will receive one 75 mg oseltamivir capsule twice daily, with or without food for a total of 5 days (10 doses). Participants one year of age and older up to a maximum weight of 88 pounds will receive a liquid form of study medication containing oseltamivir at a concentration of 15mg/ml. The dose will be based on weight:

for weight \<=33 lbs, dose=30 mg, volume per dose (15mg/mL)=2 mL two times per day x 5 days (10 doses); for weight 34-51 lbs, dose=45 mg, volume per dose (15mg/mL)=3 mL two times per day x 5 days (10 doses); for weight 52-88 lbs, dose=60 mg, volume per dose (15mg/mL)= 4 mL two times per day x 5 days (10 doses) arm 2: Identical placebo capsule twice daily for 5 days (10 doses). Participants one year of age and older up to a maximum of 88 pounds will receive a placebo syrup. The dose will be based on weight as follows: \<=33 pounds,2 mL doses, two times per day; 34 - 51 pounds, 3 mL doses, two times per day; 52-88 pounds, 4 mL doses, two times per day.

Interventions: intervention 1: Oseltamivir intervention 2: Placebo
Intervention descriptions: intervention 1: Adults and adolescents weighing greater than 88 pounds will receive one 75 mg oseltamivir capsule twice daily, with or without food for a total of 5 days (10 doses). Participants one year of age and older up to a maximum weight of 88 pounds will receive a liquid form of study medication containing oseltamivir at a concentration of 15mg/ml. The dose will be based on weight:

for weight \<=33 lbs, dose=30 mg, volume per dose (15mg/mL)=2 mL two times per day x 5 days (10 doses); for weight 34-51 lbs, dose=45 mg, volume per dose (15mg/mL)=3 mL two times per day x 5 days (10 doses); for weight 52-88 lbs, dose=60 mg, volume per dose (15mg/mL)= 4 mL two times per day x 5 days (10 doses) intervention 2: Identical placebo capsule twice daily for 5 days (10 doses). Participants one year of age and older up to a maximum of 88 pounds will receive a placebo syrup. The dose will be based on weight as follows: \<=33 pounds,2 mL doses, two times per day; 34 - 51 pounds, 3 mL doses, two times per day; 52-88 pounds, 4 mL doses, two times per day.

Protocol document: