COLUMBUS, Ohio— A condemned Ohio inmate who says he’s allergic to anesthesia is undertaking what appears to be a unique legal maneuver, arguing that no one knows how his body will react if state officials are allowed next week to inject him with the one lethal drug they now use.

A doctor is studying what impact, if any, the allergy could have on the execution process after lawyers for Darryl Durr uncovered evidence of Durr’s allergy in his 800-page prison medical record. Durr was sentenced to die for raping and strangling a 16-year-old girl in 1988.