Cocaine in all its forms stimulates the central nervous system. It causes the heart to beat more rapidly and blood vessels to constrict. This results in the demand for a greater supply of blood. But the narrowed blood vessels are unable to deliver the volume of blood demanded, which significantly increases the risk of cardiovascular incidents or strokes. With high doses, users can become delusional, paranoid, and even suffer acute toxic psychosis.
Blood pressure increases, which can cause strokes or heart attacks.
In some cases these effects have proven fatal. Crack causes the same effects as powder cocaine. Because it is smoked, however, onset is more rapid and intensity greater. Thus, the effects may be significantly exacerbated. The depression following use is described as considerably deeper and more profound.