Tamiflu, an antiviral medication which is used to treat the flu (Influenza). Tamiflu, an anti-influenza A and B medication, can also be used to treat flu symptoms in people who have had them for less than two days.

these two drugs don't have anything in common and cannot be used together since they treat different conditions. Tamiflu is used as an antiviral while Zithromax is a different antibiotic.