Amantadine-related adverse reactions among African-American elderly nursing home residents

To identify factors associated with the development of adverse reactions to amantadine prophylaxis for influenza in a predominantly African-American nursing home population, we retrospectively reviewed the records of 100 residents who did and 45 who did not receive amantadine. During the 4 weeks of amantadine treatment, three independent observers rated all new symptoms as either related or unrelated to amantadine. Two types of comparison were made. Among patients receiving amantadine, those who did or did not develop new symptoms believed to be related to amantadine were compared by age, underlying diagnoses, type and number of medications, and renal function. Similar comparisons were made between patients who did and those who did not receive amantadine. The 100 residents who received amantadine prophylaxis had significantly more nonspecific symptoms than the 45 who did not receive amantadine. Otherwise, the two groups were comparable with regard to age, renal function, number of diagnoses, and medications. Of the 100 residents given amantadine, 16% were judged to experience amantadine-related adverse reactions. Those developing amantadine-related symptoms were significantly more likely to have nonspecific symptoms and to use psychotropic medications.