I have heavy allergic to seafood. is it possible to take antihistamine drug as profilaxis to minimize allergic reaction?

No: Especially if your reaction is serious, such as anaphylaxis or hives. Avoid seafood. And consider seeing an allergist to discuss potential treatment options. Best wishes.

Not so quick: As a general rule I would not recommend prophylactic antihistamines . There are a few exceptions for which I might prophylactically treat. The issue is that the antihistamine might prevent the early phase reaction but might permit the patient to continue ingestion the offending food and end up with a more sever reaction. Must still carry your Epi-Pen or Auvi-Q!!

Will not prevent a: severe reaction. Do not chance it. A severe reaction could kill you.