My mom recently developed a blister at the location of the PICC line dressing. The nurse on call mentioned she may want to take Benadryl to help with what she believes to be an allergic reaction to the dressing. Since she was not sure if Benadryl would interact with any of my mom's current drugs, she told me to call her pharmacist. While on call with the pharmacist, I decided to just do a quick Google search for drug interactions, since this is a problem that can easily be solved with a database. The internet comes through once again! Thanks Medscape. Before the CVS pharmacist came back on the line, I already had my answer about Benadryl. I wonder if she used a similar site to look up the information she recited to me over the phone. That said, I did not know about the other interactions! Neither the doctor nor the pharmacy warned us about these other problems with an increase in OTc intervals.http://reference.medscape.com/drug-interactionchecker