Drugs that act upon the central nervous system (CNS) influence the lives of everyone, every day. These agents are invaluable therapeutically because they can produce specific physiological and psychological effects. Without general anesthetics, modern surgery would be impossible. Drugs that affect the CNS can selectively relieve pain, reduce fever, suppress disordered movement, induce sleep or arousal, reduce the desire to eat, or allay the tendency to vomit. Selectively acting drugs can be used to treat anxiety, mania, depression, or schizophrenia and do so without altering consciousness | The management of drug abuse and addiction must be individualized according to the drugs involved and to the associated psychosocial problems of the individual patient. Pharmacological interventions have been described for each category when medications are available. An understanding of the pharmacology of the drug or combination of drugs ingested by the patient is essential to rational and effective treatment. This may be a matter of urgency for the treatment of overdose or for the detoxification of a patient who is experiencing withdrawal symptoms. It must be recognized, however, that the treatment of the underlying addictive disorder requires months or years of rehabilitation. The behavior patterns encoded during thousands of prior drug ingestions do not disappear with detoxification from the drug, even after a typical 28-day inpatient rehabilitation program. Long periods of outpatient treatment are necessary. There probably will be periods of relapse and remission. While complete abstinence is the preferred goal, in reality most patients are at risk to slip back to drug-seeking behavior and require a period of retreatment. Maintenance medication can be effective in some circumstances, such as
