What is the infectious period for colds, flu and gastroenteritis? Is it true that I should take 1 Advil tablet every 4 hours or 2 tablets every 6-8 hours? Does Tylenol cause drowsiness?

Doctor: You're welcome. It is important to practice good hand hygiene to reduce the risk of contamination. It is also important to understand the period of contagion for different illnesses. Advil should be taken with caution and with the advice of a pharmacist. Tylenol may help with mild to moderate pain and may also help with sleep.