Relenza is a powder that is inhaled twice a day for five days from a breath-activated plastic device called a Diskhaler. Patients should get instruction from a health-care practitioner in the proper use of the Diskhaler, including a demonstration if required. Relenza is usually dosed 2 inhalations twice a day, approximately 12 hours apart for 5 days. Whenever possible, two doses should be taken on the first day of treatment as long as there is at least 2 hours between the 2 doses. On the following days, the doses should be about 12 hours apart at approximately the same time each day. Follow your doctor's instructions.