nausea,
vomiting,
diarrhea,
dizziness,
headache,
nosebleed,
eye redness or discomfort,
sleep problems (insomnia), or
cough or other respiratory problems.
The flu itself or Tamiflu may rarely cause serious mental/mood changes. This may be more likely in children. Tell your doctor of any signs of unusual behavior, including confusion, agitation, or self-injury.