I have had that runny nose problem on and off for several months. Very frustrating but know it is not a cold because one day I'm fine and next day it is literally falling out of me. Nice to know that perhaps it is the Herceptin and it will disappear one day when I am done.

I sometimes have a cough after herceptin and problems with food getting stuck when eating and it causes me to throw up a lot of mucus

I am currently on herceptin alone and I do get a running/ drippy nose for about a week after the meds given and then it goes away

I had it for at least 6 months after my last Herceptin.

I had the runny nose with Taxotere. It is really annoying. Because it never stopped - good grief! All the worse without nasal hair. Lol. The onc nurse knew all about all of the lesser known side effects. I finally decided that anything unusual was one. Good news is that it stopped running shortly after I finished chemo.