I took Zyban once in an attempt to give up smoking and at the same time I was taking something else for a fungal infection on my feet (I trained a lot so I probably caught it from the changing rooms). Anyway - it was a lovely hot summer so I went sunbathing one day and that night I developed hives and blew up like Michelin man. I spent a night and a day in casualty being wheeled around in a wheelchair. The thing is one of those drugs made my skin sensitive to UV so I wasn't supposed to sunbathe. The warning was in very small print so I missed it. I can't remember which drug was the offender so if you're using Zyban read the blurb just in case you want to laze around on a beach for a while and you shouldn't. My feet are fine now by the way. I took something else (what was it called?...) and it cleared up in 6 months. Aren't docs great!