Long-Term Effects Cocaine and crack constrict the heart's blood vessels, making it work harder and faster. In some users, this may trigger chest pain or a heart attack. Cocaine can interfere with the signals controlling the heart's pumping action, causing it to beat so irregularly it may stop. Cocaine, in all forms, has been associated with sudden heart attacks in people under 30, some of whom had used the drug for the first time. Cocaine and crack can cause brain seizure, a disturbance in the brain's electrical signals, some of which regulate the heart and muscles controlling breathing.
Studies show that over time, the brain appears to become more and more sensitive to cocaine.
As a result, the threshold at which seizures occur is lowered. Repeated use of the drug without experiencing problems does not guarantee that seizures will not occur. Some users have suffered strokes after using cocaine. Cocaine use triggers the release of dopamine, a chemical that transmits feelings of pleasure and well-being, in the brain. The brain requires more and more dopamine to be released to satisfy its needs, which in turn requires greater amounts of cocaine to be used.