Zanamivir appears to be more helpful in patients with a high temperature or severe symptoms. Drugs are not a panacea The CDC stresses that no medication is a substitute for vaccination. When taken for treating the flu, none of the four antiviral medications has been proven effective in preventing or minimizing serious influenza-related complications such as pneumonia or the worsening of chronic diseases. Furthermore, each can cause troublesome side effects. Rimantadine and especially amantadine can cause lightheadedness, nervousness, difficulty concentrating, and inability to sleep.
Older people are particularly vulnerable.
A recent study in the Archives of Internal Medicine evaluated 156 nursing home patients with influenza A, average age 84, who were administered both drugs sequentially. Confusion was the most common complication, followed by agitation and hallucinations. Zanamivir and oseltamivir were developed to eliminate the side effects of amantadine and rimantadine, but they can present their own problems. Oseltamivir may cause nausea and vomiting, which can be avoided by taking it with food.