A.H.
My 4-year-old did the exact same thing for a long time. It used to take me AND my husband holding her down to get the meds in her. Now we have her plug her nose, swallow the medicine (she can't taste it with her nose plugged) and then before she unplugs her nose we give her either a candy or a flavored drink. That way, when she unplugs her nose, all she tastes is the candy/drink. It works like a charm, and she doesn't have any issues at all taking medicine anymore.