Kez's hot spot had healed nicely, so I left off the buster collar. Now she has scratched it & made it bleed so we are now back to wearing it again, which hurts me

, I did buy a soft one online but it turns inside out every time she passes by something or goes into her cage, I've tried it on with & without her normal collar & inside-out, so that was a waste of money.

My question is...........I have prescribed Cetirizine Hydrochloride 10 mg (Piriton equivalent)...........would half of a tablet be harmful to her? to stop her inching, if you think it's o.k. how often would she be allowed to take it?
Waiting for the answer in anticipation

Julie