benadryl and herceptin 3 week protocol

Hello, have a question for the ladies doing herceptin on the three week schedule. I am currently doing every week and want to switch to the 3 week. Am being told with the larger dose of herceptin will need to take a large dose of benadryl, is this your experience also? As I will not be able to drive on such a large dose of benadryl it causes problems for me getting there and back. Thanks for any input -