Paun D. and Franze J. have studied and analyzed the physiological prerequisites for the harmful habit of smoking. After inhalation of a cigarette by a person with low blood pressure and possibly also with low blood sugar content, for about 20 minutes nicotine increases the blood pressure and the blood sugar level. In persons with normal blood pressure and blood sugar values, the nicotine in the blood leads to hormonal and vegetative changes in the organism, while the discontinuation of smoking leads to a decrease in the blood pressure and blood sugar values. That is why, nicotine abstinence is clinically manifested with exhaustion, tiredness, poor concentration and irritability (abstinence manifestations), which provokes a strong craving for nicotine. The abstinence syndrome can be controlled by restoring the normal blood pressure and blood sugar values by means of analeptics, tranquilizers and mostly by means of specific drugs , such as cytisine, lobeline, etc. These specific drugs "replace" nicotine by acting on the same functional receptor constellations.