However , these antihistamines may cause extreme drowsiness , therefore , people are advised to not operate heavy machinery or drive while taking this kind of medication .
Some over-the - counter options are Benadryl and Tavist .
These antihistamines may cause extreme drowsiness , therefore , people are advised to not operate heavy machinery or drive while taking this kind of medication .
Some over-the - counter options are Benadryl and Tavist .