Amphetamines are stimulants that affect the central nervous system. Medically they are used to treat depression, obesity, and other conditions.

In addition to the physical effects of amphetamines, users report feeling restless, anxious and moody. Increased doses intensify the effects, and users may become excited or talkative and experience a false sense of self-confidence or superiority. They may behave in a bizarre manner; some become aggressive and hostile.

Prolonged use of amphetamines can lead to malnutrition and vitamin deficiencies, skin disorders, ulcers, lack of sleep, weight loss and depression. Frequent use of large amounts of amphetamines can cause brain damage that results in speech and thought disturbances.

Note: "Speed" is used to refer to amphetamine, methamphetamine, methylphenidate (Ritalin), and other strong stimulants that feel something like amphetamine.

Users of large amounts of amphetamines over a long period of time can develop an amphetamine psychosis, which is a mental disorder similar to paranoid schizophrenia. The psychosis is manifested by hallucinations, delusions, and paranoia. Bizarre, sometime violent, behavior is exhibited by those with amphetamine psychosis. Symptoms usually disappear within a few weeks after drug use stops.

Amphetamines have the potential to produce tolerance, which means that increased amounts of the drug are needed to achieve the desired effects. Withdrawal symptoms can occur when use of amphetamines is stopped abruptly. Users may experience fatigue; long, disturbed periods of sleep; irritability; intense hunger, and moderate to severe depression. The length and severity of the depression is related to how much and how often amphetamines were used.

• craving
• exhaustion
• depression
• mental confusion
• restlessness and insomnia
• deep or disturbed sleep lasting up to 48 hours
• extreme hunger
• psychotic reaction
• anxiety reactions

Medical treatments include the use of antidepressant agents such as imipramine, desipramine, amitriptyline, dosepin, trazodone, or fluoxetine (Prozac). These affect serotonin, the neurotransmitter in the brain that deals with both depression and drug craving.

Sedatives such as Dalmane, chloral hydrate, Librium, phenobarbital, or even Valium are used, very carefully, on a short-term basis to treat anxiety or sleep disturbance problems. Antipsychotic medications such as Haldol, Thorazine, and others are also used to buffer the effects of unbalanced dopamine, the neurotransmitter that moderates paranoia and pleasurable sensation.

In addition to treating the physical and psychological aspects of craving, treatment providers should stress group counseling and peer pressure for compulsive amphetamine users, as these forms of therapy work well for this population.

It is possible for babies of mothers who use amphetamines to be born with:

• cardiac defects
• cleft palate
• birth defects
• addiction and withdrawal

(from PDR 1998's amphetamine prescription information)
Individual patient response to amphetamines varies widely. While toxic symptoms occasionally occur as an idiosyncracy at dosages as low as 2 mg, they are rare with doses of less than 15 mg; 30 mg can produce severe reactions, yet doses of 400 to 500 mg are not necessarily fatal. In rats, the oral LD50 of dextroamphetamine sulfate is 96.8 mg/kg.

Manifestations of acute overdosage with amphetamines include restlessness, tremor, hyperreflexia, rapid respiration, confusion, assaultiveness, hallucinations, panic states, hyperpyrexia, and rhabdomyolysis.

Fatigue and depression usually follow the central stimulation.

Cardiovascular effects include arrhythmias, hypertension or hypotension, and circulatory collapse.

Gastrointestinal symptoms include nausea, vomiting, diarrhea, and abdominal cramps. Fatal poisoning is usually preceded by convulsions and coma.

Consult with a Certified Poison Control Center for up-to-date guidance and advice. Management of acute amphetamine intoxication is largely symptomatic and includes gastric lavage, administration of activated charcoal, administration of a cathartic and sedation. Experience with hemodialysis or peritoneal dialysis is inadequate to permit recommendation in this regard. Acidification of the urine increases amphetamine excretion, but is believed to increase risk of acute renal failure if myoglobinuria is present. If acute, severe hypertension complicates amphetamine overdosage, administration of intravenous phentolamine (Regitine (r) CIBA) has been suggested. However a gradual drop in blood pressure will usually result when sufficient sedation has been achieved. Chlorpromazine antagonizes the central stimulation effects of amphetamines and can be used to treat amphetamine intoxication.