Amphetamines, introduced as an over-the-counter nasal decongestant in the United States in 1931, were abused after World War II through diversion from pharmaceutical plants and delivery trucks. Legislation was largely successful in removing pharmaceutical amphetamines from the street by reducing production. This was followed by look-alike tablets that generally contain caffeine, ephedrine, and phenylpropanolamine. This chapter describes the physically detrimental effects of these look-alikes and the efforts to control their availability. After reviewing the recent history of cocaine, the cocaine derivatives of pasta, free-base, and crack are discussed, with attention to their toxic effects. The chapter concludes with a discussion of the symptoms and treatment for the abuse of stimulants and stimulant look-alikes. Topics in this section include the treatment of acute and chronic stimulant abuse, acute stimulant toxicity, chronic stimulant toxicity, withdrawal, and recovery. 15 notes.