As recommended by the World Health Organization (WHO), oseltamivir (Tamiflu) is currently used for people with influenza A. In previous pandemics, the virus was susceptible to amantadine and rimantadine. If they are safe and the circulating strain proves to be susceptible to these drugs, they could be an alternative for managing influenza. We therefore wanted to answer the question of whether or not amantadine and rimantadine can prevent and treat influenza A in children and the elderly.
Influenza A is a respiratory infection causing cough, runny nose and fever. Most symptoms pass without treatment within three to seven days. However, hospitalisation, pneumonia and even death are rare complications of the illness, especially among children and the elderly. Pandemics are also a cause for concern.
Key results and quality of the evidence
We identified 12 trials (2494 participants: 1586 children and 908 elderly). We looked for trials that compared amantadine or rimantadine with no intervention, placebos or control drugs in children and the elderly. The most recent searches were completed in October 2014. We looked at several outcomes, including influenza A, fever duration, cough, headache, nausea/vomiting, dizziness and stimulation/insomnia.
Although amantadine was effective in preventing influenza A in children, it would be necessary to use it in up to 17 children over a period of 14 to 18 weeks to prevent one case of influenza A. Furthermore, the safety of the drug was not well established. The quality of the evidence was low.
The effectiveness of both antivirals was limited to a benefit from rimantadine in the reduction of fever by day three of treatment in children. The quality of the evidence was moderate. This benefit does not seem to justify a recommendation for using rimantadine to treat all children with influenza A.
Rimantadine did not show a prophylactic (preventative) effect in the elderly. The quality of evidence was very low.
The quality of the evidence combined with a lack of knowledge about the safety of amantadine and the limited benefits of rimantadine, do not indicate that amantadine and rimantadine compared to control (placebo or paracetamol) could be useful in preventing, treating and shortening the duration of influenza A in children and the elderly.