Does antihistamine pills like Zyrtec (cetirizine) help with the lower eyelid puffiness?

It Can. If your lower eyelid puffiness is caused by allergies then Zyrtec might help though a nasal steroid spray like Nasacort (triamcinolone) or Flonase will work better. If your eyelid puffiness is from lack of sleep or genetics then it will not help.