I found this: https://www.differencebetween.com/difference-between-caffeine-and-vs-nicotine/
"While caffeine, can lead to mental alertness and helps in remaining awake once in a while, increasing the dose or taking it regularly many times can cause jitteriness and nervousness. It can also cause upset stomach and headaches. There is difficulty in concentrating contrary to popular misconception that one gets concentration after a cup of coffee. In some people, it hinders with regular sleep and increases heart rate and blood pressure.
Nicotine is certainly more dangerous than caffeine as regular intake over a period of a few years can cause many ailments or at least lead to symptoms that need medical attention. What is bad about nicotine is that initially it provides a kick that is very pleasurable but once a person becomes habitual, he needs a higher dose to get the same kick. This goes on and a stage comes when consumption does not give any kick and it is merely required by the blood of the person which has the presence of nicotine in it. Nicotine stimulates when it is consumed and also acts like a relaxant. It releases adrenaline and increases the metabolic rate of a person. Excessive intake of nicotine leads to cancer of lungs and high blood pressure, both of whom are silent killers."
