Crack is far more addictive than heroine or barbiturates. Repeated use of crack can lead to addiction within a few days. Once addicted, many users have turned to stealing, prostitution, and drug dealing in order to support the habit. The effects of crack are felt within ten seconds. The physical effects include dilated pupils, increased pulse rate, elevated blood pressure insomnia, loss of appetite, tactile hallucinations, paranoia, and seizures.
Continued use can produce violent behavior and a psychotic state similar to schizophrenia.
Cocaine in any form, but particularly in the purified form known as crack, can cause sudden death from cardiac arrest or respiratory failure.