Hi I Have Been Taking The Generic For Zovirax To

Hi I have been taking the generic for Zovirax to treat fever blisters. It seems that it causes sleepiness, but I haven't seen tiredness/sleepiness listed as a side effect. It says to take five per day, is that maybe too much for me? It works great on the fever blisters when I take it frequently, although I don't typically take five doses per day.