Xofluza should be used within 48 hours of noticing symptoms of influenza, Take Xofluza without regard to meals., Avoid taking Xofluza at the same time as dairy products or antacids that contain calcium, iron, magnesium, zinc, or selenium., Your dose of Xofluza depends on your weight: 40-80kg - Take two 20mg tablets by mouth as a single dose. 80kg or greater - Take two 40mg tablets by mouth as a single dose., 40-80kg - Take two 20mg tablets by mouth as a single dose., 80kg or greater - Take two 40mg tablets by mouth as a single dose. 40-80kg - Take two 20mg tablets by mouth as a single dose., 80kg or greater - Take two 40mg tablets by mouth as a single dose.