Anti-Parkinson’s medication also helps prevent influenza

DEAR DR. ROACH »

About 20 years ago,

I was prescribed amantadine to offset the side effects of psychiatric medications I was being given. I also have always been predisposed to serious flu complications, even though I did get flu shots. Amantadine not only helped with side effects, but I very seldom got the flu.

Then my doctor thought it best that I end the amantadine. I ended the medication some six months ago, and after the first month, I once again was experiencing multiple occurrences of respiratory problems. Flu, bronchitis, pneumonia, etc., and some slight symptoms of less desirable effects from the psychiatric medications have reappeared.

— R.L.O.

ANSWER » Amantadine was approved by the Food and Drug Administration in 1968 as a preventive and treatment for the Asian influenza pandemics of the time. It works by blocking a viral protein specific for influenza and wouldn’t be expected to be effective against other respiratory viruses.

In 1969, a woman taking it for influenza noted dramatic improvement in her Parkinson’s disease symptoms, which worsened again once she stopped it. So the drug was tested for use in Parkinson’s disease. After studies showed success, it was approved by the FDA for Parkinson’s.

Some psychiatric medications can cause Parkinson-like side effects, and amantadine is used to combat those side effects if the psychiatric medicines cannot be changed.

Because the action of amantadine is so specific against flu, taking it wouldn’t have an effect on bronchitis or pneumonia outside those triggered by seasonal influenza. Amantadine is not as effective as vaccination at preventing flu, so continue getting the flu shot. Schedule a visit with a psychiatrist, who generally has more experience treating side effects of psychiatric drugs than primary care doctors. You may still need amantadine or something else to help with those side effects. Benztropine is the usual medication used now.

Contact Dr. Roach at ToYourGoodHealth@med. cornell.edu.