Is it possible for me to take haldol (haloperidol) while allergic to thorazine?

With caution, yes: It is possible for an individual to be allergic to Chlorpromazine while being not allergic to haloperidol. The two medications are in the same division in the family of medications in that they are both typical antipsychotics although they have differences in potency. I would talk to your md and listen to your body carefully. Any disturbing changes or side effects should be evaluated quickly!