He told her that if she was not going to be able to quit cold turkey, which was obviously best, then it would at least be better to get the nicotine through replacement therapy rather than a cigarette as it would cut down on all of the other toxins
and blood gas changes. That was 5 years ago,
and things change,
and every Dr. has their own permissions, so please call and ask them.
As an ex-smoker I know it's very very difficult to quit.