Hello, I'm Mike Clarke, podcast editor for the Cochrane Library. The Library contains several reviews of treatment for people with influenza and, one of these, published in November 2014, looks at the evidence for amantadine and rimantadine.

It focuses on influenza A, which is a respiratory infection that causes symptoms such as cough, runny nose, and fever. These usually disappear without treatment within three to seven days but, in some rare cases, complications such as hospitalisation, pneumonia, and even death may occur, particularly among children and the elderly. Concerns about this have been increased by the risk of pandemics and the possibility that more recent medications and vaccines may not be available for everyone. It's important, therefore, to know if older medicines might help and, in previous pandemics, the antivirals amantadine and rimantadine showed good results against influenza A. If these positive outcomes were also demonstrated against current strains of the virus and, if the drugs are safe, they could be an alternative treatment. Therefore, this team of Cochrane reviewers based in Brazil investigated whether amantadine and rimantadine could prevent and treat influenza A in two vulnerable groups: children and the elderly.
They identified 12 studies, which included a total of nearly 1600 children and just over 900 elderly people, and compared amantadine or rimantadine with no treatment, placebo or medication to relieve symptoms. They analysed the effects on various outcomes, including occurrence of influenza A, duration of fever, cough, headache, nausea and vomiting, dizziness, and stimulation or insomnia.Starting with prevention: although amantadine was effective in preventing influenza A in children, it would require, on average, the treatment of 17 children for 14 to 18 weeks to prevent a single case of flu A. Additionally, the safety of the drug was not well established, although the quality of evidence for this was low. The quality of the evidence was also very low for rimantadine, and it showed no preventive effect in the elderly.For treatment, both medications had limited effectiveness. Based on moderate quality evidence, rimantadine reduced fever by the third day of treatment in children but the benefit does not seem significant enough to recommend its use for all children with flu A.In summary, taking into account the quality of evidence and the lack of knowledge about amantadine's safety and the limited benefits of rimantadine, the Cochrane Review concludes that there is no indication that either drug could be useful in preventing, treating, or reducing the duration of flu A symptoms in children and the elderly.

If you would like to look in more detail at the existing evidence, the review is free to read and download online. If you go to Cochrane Library dot com and search "amantadine and rimantadine for influenza A", you'll see a link to it.