I took a prescription that i previously too before with no reaction. but this time (1 year later i developed hives on my torso witg no other reaction ( outher that the hives itching) the script is benzonatate 200 mg capsule. how do i counteract this?

Reactions that are localized to one area/region are usually due to a contact trigger rather than a drug. Something like residual sizing in a new article of clothing covering the trunk would be an example. That said, people can develop an allergy to any material they once did not. Antihistamines like Benadryl/Zyrtec can help with hives or itching but not cancel the allergy.