Caffeine & Stimulants

Generally, drugs such as caffeine that are classified as stimulants increase central nervous system activity. Stimulants often have the effect of decreasing feelings of fatigue, giving you more energy. Caffeine and other stimulant drugs act to increase alertness, mental and physical endurance. Stimulants work by triggering the release of dopamine, adrenaline and noradrenaline – neurotransmitters that have the effect of elevating your mood.

Effects of Stimulants on Other Body Systems

Caffeine stimulates the heart and may increase your pulse rate. The stimulant constricts cerebral blood vessels, which might be the cause for some types of headaches. Excessive caffeine consumption increases the production of gastric acid secretions, causing stomach irritation. Caffeine is also a mild diuretic, which can cause an increase in urine excretion. Herbal stimulants such as ephedra – sometimes used in dietary supplements, particularly those used for weight loss and bodybuilding – have also been associated with potential health risks. Ephedra affects the heart and circulatory system and can be dangerous if you have an existing heart condition.

More About Ephedra

Ephedra contains ephedrine akaloids – chemical compounds that stimulate the central nervous system, dilating lung airways and narrowing blood vessels. The Mayo Clinic reports that the use of ephedra has been linked to health concerns such as high blood pressure, tachycardia, heart attack and stroke. As of 2011, the sale of products containing ephedra is banned in the United States.

Side Effects Symptoms

Although caffeine consumed in moderate amounts is generally safe for most people, it has the potential to cause adverse side effects such as tremors, restlessness, insomnia and headaches. Individuals who consume caffeine in excess of 10 cups of coffee a day may experience symptoms including extreme anxiety, nervous twitches, visual hallucinations and fast heart rate, according to University of Utah College of Pharmacy. The regular use of caffeine has also been associated with an increase in the frequency and severity of premenstrual syndrome. Common side effects of stimulant medications that doctors sometimes prescribe to treat attention deficit/hyperactivity disorder in children may include irritability, difficulty sleeping, involuntary muscle movements, reduced appetite and weight loss.

Products That Contain Caffeine

Coffee, tea, cocoa and soft drinks are not the only products that are sources of the stimulant caffeine. Over-the-counter analgesics and cold medicines often contain caffeine as well. Weight control products and non-prescription drugs advertised as stimulants to help you stay awake may contain caffeine. Even some prescription medications used to treat headaches and pain contain caffeine and other stimulants.