They cause an increased heart rate and blood pressure. High doses can cause a rapid or irregular heart beat, tremors, loss of coordination, and even physical collapse. Even more dangerous are amphetamine injections. An injection creates a sudden increase in blood pressure that can cause death from stroke, very high fever, or heart failure. Other side effects include nervousness, paranoia, halluncinatins, dizziness, decreased mental ability, psychosis, seizures, sexual impotence and death.
Cocaine can also have serious consequences.
Its' immediate effects are brief euphoria, increased energy, and intense exhilaration. The user's pupils become dilated, their heart rate, breathing rate, blood pressure and body temperature also increases. Continued use can cause tremors, nasal bleeding and inflamation, toxic psychosis, seizures, and even death from an overdose is possible. Drugs are not something to be experimented with. There is no guarantee that the one time you use it.