They affect the brain and central nervous system by producing a powerful sense of euphoria, along with extreme alertness, increased energy, nervous excitement, irritability, and insomnia. Other effects of amphetamines include an increase in heart and respiration rates and in blood pressure. The pupils become dilated, and there is usually a decrease in appetite. It is not unusual for the casual user to experience dry mouth, dizziness, sweating, headache, blurred vision, sleeplessness, and anxiety.
High doses can cause irregular heartbeats and severe tremors.
Frequent users are subject to greatly increased chances of stroke or heart failure. Tolerance to the drug builds rapidly, requiring increases in the amount of the drug to produce the desired effect. Chronic users suffer from side-effects, including increased aggression, fear, hallucinations, or seizures. For more information about amphetamines, contact a health care provider. Use of the information and materials on this server is subject to the terms and conditions contained on the Legal Information page.