Nicotine in any form has serious I'll effects on your blood vessels, heart, brain etc. Any form of Nicotine for medical reason is not advised. Continue your Methylphenidate
which keeps you on right track.
On next consultation with your paediatrician, discuss it in detail.
I suggest you to not to experiment with any Nicotine containing substances or other forms of abusive drugs which will affect badly (more than non ADHD
people) on your health. Being teenager, channel your extra energy in some other creative work. Find new means of enjoyment than depending on substances.