Thanks for choosing HCM for asking your query.
From the information given by you, it doesn't appear that you using nicoderm
patches and smoking
over it is related to the pain in your thigh. The pain on the back of thigh can occur due to many reasons most common being any musculo-skeletal trauma. May be you can use some stretches or visit a physiotherapist who can help you with some exercises. Long term use of nicotine
does cause blockage of blood supply but then that starts from the peripheries and not from the thighs. Its always better to quit smoking and you should re-initiate your efforts to quit it.
Hope I am able to solve your query. Have a nice day.