Crack cocaine is a solid, smokable form of cocaine. It is a freebase form of cocaine that can be made using baking soda (sodium bicarbonate) or sodium hydroxide, in a process to convert cocaine hydrochloride (powder cocaine) into methylbenzoylecgonine (freebase cocaine).

Physiological effects

The short-term physiological effects of cocaine include

An appreciable tolerance to cocaine's high may develop, with many addicts reporting that they seek but fail to achieve as much pleasure as they did from their first experience. Some users will frequently increase their doses to intensify and prolong the euphoric effects. While tolerance to the high can occur, users might also become more sensitive (sensitization) to cocaine's anesthetic and convulsant effects, without increasing the dose taken.

Addiction

Crack cocaine is the most addictive form of cocaine,

The intense desire to recapture the initial high is what is so addictive for many users. Purer forms of crack cocaine will produce the feeling of euphoria: Even after smoking diluted or fake crack for hours, one hit of real crack will produce euphoria. Hours of misery or tweaking can be reversed with one single hit of real crack. The memory of that type of high can cause addicts to buy large amounts of street crack, hoping for the real thing. Injecting crack causes a very intense rush which will be shortly followed by an equally intense comedown; this is why some users will mix it with heroin—to cushion the comedown with its numbing, pain-relieving effects.

However, the craving is also part of the addiction. Due to the high level of dependence it creates, the crack addicts need it every day. The addictive properties are very strong.

Health issues

Because crack also refers to non-pure (or fake) versions of rock cocaine, the health issues also include risks beyond smoking cocaine. However, crack usage is less dangerous than speedballing or "snowballing" (mixing cocaine with heroin), which leads to more fatalities than either drug used on its own.

When large amounts of dopamine are released by crack consumption, it becomes easier for the brain to generate motivation for other activities. The activity also releases a large amount of adrenaline into the body, which tends to increase heart rate and blood pressure, leading to long-term cardiovascular problems. It is suggested by research that smoking crack or freebase cocaine has additional health issues beyond other methods of taking cocaine. Many of these issues relate specifically to the release of methylecgonidine, and the specific effect of methylecgonidine on the heart, lungs, and liver.