I am certain you know where this is going…let’s take the treatment of confirmed influenza as an example. Oseltamivir 75mg PO post-HD for five days is recommended for treatment of influenza onset within the past 48h. Since oseltamivir is removed by high-flux HD, this can mean post-HD x 2 or 3 doses depending on the number of days between sessions. To simplify this, I have been recommending 3 doses (in cases where a clinical pharmacist is not readily available). This avoids under dosing however may result in a longer treatment time. The consequences of a prolonged influenza infection in this population include nausea, vomiting, diarrhea, missed HD sessions, increased risk of complications and acute hospital admission. Consequences of extended treatment include an increase in medication cost for the hospital (one capsule per incidence) and increased side effects such as headache (2-17%), nausea (8-10%) and vomiting (2-16%). With the knowledge that simplicity can reduce under dosing for a medication not routinely ordered, this generalized recommendation seems justifiable although an assessment of treatment days would be ideal.