If these more severe symptoms are present, get medical attention immediately, such as dialing 911 or going directly to the closest emergency room. While waiting for emergency medical help, if the sting victim has injectable epinephrine that was prescribed to them, use it immediately. Give the person an oral antihistamine (such as Benadryl, Zyrtec, Claritin or Allegra) only if the sting victim is able to swallow and does not have severe swelling of the tongue, lips or throat. Choking on medicine could make an already dangerous situation much worse.