Central nervous system (CNS) stimulants are medicines that stimulate the release of excitatory chemicals (primarily norepinephrine) from nerve cells, increasing brain and nerve activity.
By increasing brain and nerve activity, these drugs increase wakefulness and speed thinking and physical processes.
The most commonly used central nervous system stimulant is caffeine.
Central nervous system stimulant drugs are used to treat daytime lethargy and sleepiness and, paradoxically, attention deficit and hyperactivity disorders, presumably by improving the ability to organize, focus, and concentrate mental activities.
Examples of central nervous system stimulants include modafinil (Provigil), sibutramine (Meridia), combinations of dextroamphetamines (Adderal), and methylphenidate (Ritalin, Concerta).
With the exception of caffeine, which is available in a host of consumer products, these drugs are highly regulated, Class II narcotics.
These drugs are available in tablets, capsules, liquids, and patches.
Studies on pregnant animals showed fetal teratogenic effects. They are not used in pregnant women unless the benefits outweigh potential risks. Nursing mothers pass small amounts of these drugs through their milk to babies.
Children with structural abnormalities or diseases of the heart are at risk for sudden death from taking these drugs. Before they are prescribed, children should be given a careful cardiac evaluation.
Adults with heart abnormalities or diseases are at risk for sudden death, stroke, or heart attack from taking these drugs. For these reasons, a thorough cardiac evaluation is a required first step.
Other critical notes. CNS stimulants:
- can increase blood pressure and should be taken with caution by anyone who has hypertension or hyperthyroidism
- may increase manic episodes in people with bipolar disorder, and they can exacerbate aggressive behavior, psychosis, and thought disorders
- may increase the likelihood of seizures in people with seizure disorder
- should be used with caution by people who have a history of alcohol or drug abuse as they may produce drug-dependency and should not be withdrawn abruptly after prolonged use
- become increasingly tolerated by the brain, so increasing doses are often needed to maintain the desired effects
- are not approved for use in children under the age of six; their use has been associated with growth retardation
- angina, heart attack, and increased heart rate and arrhythmias
- high blood pressure
- agitation and restlessness
- anger and aggression
- abdominal pain
- decreased appetite
- nausea, vomiting, and diarrhea
When taken with monoamine oxidase inhibitors (MAOI) (Marplan, Nardil, Parnate), CNS stimulants can produce dangerously high blood pressure.
Patients who stop taking CNS stimulants, particularly after extended use, may experience significant fatigue, depression, and sleep disorders.