A/H1N1 Flu Update: Tamiflu's Side Effects

Oseltamivir’s (Tamiflu) adverse events

Letter to British Medical Journal: Published 11 August 2009, doi:10.1136/bmj.b3249
Cite this as: BMJ 2009;339:b3249

• Local community based surveillance in South Yorkshire during July 2009 indicates that only 11% (95% confidence interval 7% to 17%) of people with flu symptoms were positive for A/H1N1.
• Many patients who use the National Pandemic Flu Service may therefore be offered antiviral drugs unnecessarily with risk of adverse effects.¹

• After a school outbreak of A/H1N1 flu treated with oseltamivir during the containment phase of the current pandemic (273 pupilsand 53 staff, 51 pupils and 10 staff reporting flu-like illness) adverse effects were reported by 113 pupils (41%, 95% confidence interval 35% to 47%) and 25 staff (47%, 33% to 61%).

• The most commonly reported adverse effects (>10% of sample) were
  

nausea (26%, 22% to 32%),


abdominal pain (20%, 15% to 24%), and


headache (12%, 8% to 16%).

• No life threatening adverse effects were reported, but two respondents reported psychological disturbance.