Amphetamines increase alertness, enhance physical performance, and produce euphoria and a sense of well-being.
Amphetamines suppress appetite and some people misuse amphetamines to lose weight.
An overdose can cause extreme agitation, delirium, and a life-threatening high body temperature, heart attack Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina) Acute coronary syndromes result from a sudden blockage in a coronary artery. This blockage causes unstable angina or heart attack (myocardial infarction), depending on the location and amount... read more
, or stroke Overview of Stroke A stroke occurs when an artery to the brain becomes blocked or ruptures, resulting in death of an area of brain tissue due to loss of its blood supply (cerebral infarction) and symptoms that... read more .Urine tests can detect most amphetamines.
For an overdose, treatment involves sedatives, blood pressure–lowering drugs and sometimes cooling treatments.
(See also Drug Use and Abuse Overview of Substance-Related Disorders Drugs are an integral part of everyday life for many people, whether the drugs are used for legitimate medical purposes or recreationally (see table Drugs with Medical and Recreational Uses)... read more .)
Amphetamines include the drug amphetamine and its many variants such as methamphetamine (speed or crystal meth) and methylenedioxymethamphetamine (MDMA, Ecstasy, or Adam). Methamphetamine is the most commonly used amphetamine in the United States. Use of MDMA Methylenedioxymethamphetamine (MDMA) MDMA (3,4-methylenedioxymethamphetamine) is a drug similar to an amphetamine but has both stimulant and hallucinogenic effects. (See also Amphetamines and Overview of Substance-Related Disorders... read more is growing in popularity. Amphetamines are usually taken by mouth but can be snorted, smoked, or injected.
Because some amphetamines are widely used as treatment for attention-deficit/hyperactivity disorder Attention-Deficit/Hyperactivity Disorder (ADHD) Attention-deficit/hyperactivity disorder (ADHD) is poor or short attention span and/or excessive activity and impulsiveness inappropriate for the child’s age that interferes with functioning... read more , obesity, and narcolepsy Narcolepsy Narcolepsy is a sleep disorder marked by excessive sleepiness during the day or recurring, uncontrollable episodes of sleep during normal waking hours, usually with sudden episodes of muscle... read more , there is a ready supply that can be diverted to illegal use. Some amphetamines are not approved for medical use and are manufactured and used illegally.
Some amphetamine users are depressed and seek the mood-elevating effects of these stimulants to temporarily relieve the depression Depression A short discussion of prolonged grief disorder. Depression is a feeling of sadness and/or a decreased interest or pleasure in activities that becomes a disorder when it is intense enough to... read more . Others use them during high-energy activities. Amphetamines cause more dopamine to be released in the brain. (Dopamine is a neurotransmitter, a substance that helps nerve cells communicate.) This effect is the likely cause of mood elevation. MDMA Methylenedioxymethamphetamine (MDMA) MDMA (3,4-methylenedioxymethamphetamine) is a drug similar to an amphetamine but has both stimulant and hallucinogenic effects. (See also Amphetamines and Overview of Substance-Related Disorders... read more differs from other amphetamines in that it also interferes with the reuptake of serotonin (another neurotransmitter) in the brain. Amphetamine users frequently develop dependence, often referred to as a substance use disorder Substance Use Disorders Substance use disorders generally involve behavior patterns in which people continue to use a substance despite having problems caused by its use. The substances involved tend to be members... read more .
Symptoms
Amphetamines use causes both immediate and long-term symptoms.
Immediate effects
The following are some immediate effects of amphetamine use:
Increased alertness
Reduced fatigue
Heightened concentration
Decreased appetite
Enhanced physical performance
Amphetamines may produce a feeling of well-being, euphoria, and loss of inhibitions. Also, people sweat profusely, and their pupils are dilated.
Binge usage (perhaps over several days) eventually causes extreme exhaustion and a need for sleep.
Overdose
High doses (overdose) increase blood pressure and heart rate. These increases may be life threatening. People may become extremely paranoid, violent, and out of control.
People may become delirious. Heart attacks Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina) Acute coronary syndromes result from a sudden blockage in a coronary artery. This blockage causes unstable angina or heart attack (myocardial infarction), depending on the location and amount... read more have occurred, even in healthy young athletes. Blood pressure may become so high that a blood vessel in the brain ruptures, causing a stroke Overview of Stroke A stroke occurs when an artery to the brain becomes blocked or ruptures, resulting in death of an area of brain tissue due to loss of its blood supply (cerebral infarction) and symptoms that... read more . Other effects include dizziness, nausea, vomiting, diarrhea, seizures, and a life-threatening high body temperature (hyperthermia Serotonin Syndrome Serotonin syndrome is a potentially life-threatening drug reaction that tends to cause high body temperature, muscle spasms, and anxiety or delirium. Serotonin is a chemical that transmits impulses... read more ).
Long-term effects
People who habitually use amphetamines rapidly develop tolerance Intoxication as part of dependence. They need to use more and more to get the same effect. The amount ultimately used may be more than several times the original dose. Most people using very high doses over several days or weeks become confused and psychotic because amphetamines can cause severe anxiety, paranoia, and a distorted sense of reality.
Psychotic reactions include hearing and seeing things that are not there (auditory and visual hallucinations) and false beliefs (delusions), such as a feeling of having unlimited power (omnipotence) or of being persecuted (paranoia). Memory may be affected. Confusion, memory loss, and delusions may last for months. Although these effects can occur in any user, people with a mental health disorder, such as schizophrenia Schizophrenia and Related Disorders , are more vulnerable to them.
Methamphetamine users have a high rate of teeth grinding (bruxism) and severe tooth decay affecting numerous teeth. The causes include decreased salivation, corrosive substances in the smoke, and poor oral hygiene—called "meth mouth."
Withdrawal symptoms
When an amphetamine is suddenly stopped, symptoms vary. People dependent on amphetamines become tired or sleepy—an effect that may last for 2 or 3 days after stopping the drug. As a result, they are more likely to be injured.
Some people are extremely anxious and restless, and some, especially those with a tendency toward depression Depression A short discussion of prolonged grief disorder. Depression is a feeling of sadness and/or a decreased interest or pleasure in activities that becomes a disorder when it is intense enough to... read more , become depressed when they stop. They may become suicidal but may lack the energy to attempt suicide for several days.
Diagnosis
A doctor's evaluation
A history of amphetamine use
Doctors base the diagnosis on symptoms in people known to have taken amphetamines. If the diagnosis is unclear, urine tests may be done, but the test may not detect methamphetamine and methylphenidate (a stimulant drug related to amphetamines).
Other tests, such as electrocardiography Electrocardiography Electrocardiography (ECG) is a quick, simple, painless procedure in which the heart’s electrical impulses are amplified and recorded. This record, the electrocardiogram (also known as an ECG)... read more 
, computed tomography Computed Tomography and Magnetic Resonance Imaging of the Digestive Tract Computed tomography (CT—see also Computed Tomography (CT)) and magnetic resonance imaging (MRI—see also Magnetic Resonance Imaging (MRI)) scans are good tools for assessing the size and location... read more , and blood tests, may be done to check for complications.
Treatment
After an overdose, treatment may include
Sedatives
Blood pressure–lowering drugs
Cooling for hyperthermia (dangerously high body temperature)
Treatment for depression and suicidal tendencies during withdrawal period
Cognitive-behavioral therapy to prevent relapse
Benzodiazepines (a group of sedative drugs), such as lorazepam, are given intravenously to people with severe symptoms such as high blood pressure, extreme agitation, or seizures.
Drugs for high blood pressure, such as labetalol or hydralazine, are given intravenously if blood pressure remains high.
Cooling treatments, such as wetting the patient and blowing air over the skin or using special cooling blankets may be needed to correct hyperthermia Serotonin Syndrome Serotonin syndrome is a potentially life-threatening drug reaction that tends to cause high body temperature, muscle spasms, and anxiety or delirium. Serotonin is a chemical that transmits impulses... read more .
During drug withdrawal, long-term users may need to be hospitalized so that they can be observed for suicidal behavior. Antidepressants Drug Treatment for Depression Agomelatine, a new type of antidepressant, is a possible treatment for major depressive episodes. Several types of drugs can be used to treat depression: Selective serotonin reuptake inhibitors... read more may be given if depression persists. Otherwise, no treatment is generally needed for people experiencing withdrawal.
Cognitive-behavioral therapy (a form of psychotherapy) helps some people stay free of amphetamines.
