Mrs. Smith tells you that her high school reunion is 4 days from today and she really wants to go. What will you tell her?
D) I can prescribe a drug that may shorten the duration of your illness.
Correct. Please choose another answer.
Amantadine (200 mg/day) or rimantidine (100 mg bid) if given early (first 48 hours) in an influenza A infection, can shorten the duration of illness and virus shedding by 1-3 days. Whether this relatively small increase in recovery time is worth the cost of the drug (average wholesale price is $0.19/capsule for amantadine and $1.37/capsule of rimantadine) needs to be decided on a case-by-case basis, but in this situation it just might get her to her reunion. The side effects of amantadine are CNS (anxiety, nervousness, difficulty concentrating, light-headedness) and GI (nausea, anorexia). These occur less frequently with rimantadine, but are still sufficiently troublesome that some patients will stop taking the medication. Please note that these medications are only effective for influenza A isolates, not influenza B. A newly licensed agent, zanamavir, may help cicumvent this problem as it is effective against both influenza A and B. Zanamavir is a neuraminidase inhibitor and is given by inhalation. It also decreases the duration of illness by 1 to 3 days and the risk of infection. It has very few side effects.