Caffeine takes about an hour to affect you and usually lasts 4-6 hours. Because caffeine is a stimulant, most people experience increased alertness, blood pressure, and breathing rate. These effects are generally due to caffeine increasing the metabolic rate of human body and sometimes it is linked to weight loss. The drug is a diuretic, causing increased urination which can lead to dehydration. Long-term use of coffee can lead to nervousness, insomnia, dehydration, stomach irritation, and fatigue.
When you inhale cigarette smoke, your lungs are punished with tar and many gases, including carbon monoxide. Nicotine, found in tobacco, affects the central nervous system as a stimulant. Once nicotine is taken into the body, blood sugar rises a little, giving you increased energy that will soon cave in and leave you fatigued and perhaps depressed, fueling the craving for more nicotine. It tightens blood vessels and restricts blood flow, causing lasting damage to arteries in the long run.
According to this information both coffee and cigarettes are stimulants but one restricts blood flow while the other increases blood flow. It seems this would also mean that having both together puts additional strain on the heart itself, causing it to work against itself and creating an environment for uneven energy loss and depression which could then cause psychological, and physical pressure to continue consuming both drugs together. However latest researches show that a small amount of these two drugs can have some beneficial effects and are actually recommended to help ward off diseases like Alzheimer’s, dementia and prostate cancer.