Amphetamines (often referred to as “speed”) are highly addictive drugs that stimulate the central nervous system, raising blood pressure, heart rate and metabolism. There are three kinds of amphetamines: amphetamines, dextroamphetamine and methamphetamine. Amphetamines are prescribed by doctors to lift mood in those who are depressed and to treat narcolepsy, obesity and hyperactivity in children. Some trademarked prescription drugs that contain amphetamines are Adderall, Desoxyn, Biphetamine, Dexotrostat, Cylert, Dexedrine, Dextrostat, Desoxyn, ProCentra, and Vyvanse. Side effects of amphetamines can include nervousness, restlessness, headache, dry mouth, difficulty falling asleep or staying asleep, uncontrollable shaking and digestive problems such as diarrhea, nausea, vomiting and constipation. Signs of a serious reaction to these drugs include difficulty breathing, hallucinations, rashes, seizures, weakness in arms or legs, blurred vision, chest pain, shortness of breath and mania. But the biggest danger of using amphetamines without medical supervision is addiction. During chemical withdrawal from amphetamines, an addict may experience depression, fatigue, insomnia, delusions, hallucinations, irritability and suicidal thoughts.