Crack is a form of cocaine that acts as a stronger central nervous system stimulant and is one of the most addictive of all drugs.
Crack continues to be a very serious drug problem in the United States and many other countries around the world. The term "crack" refers to the crackling sound heard when the substance is heated, presumably from the sodium bicarbonate that is used in the production of crack. Crack is almost always smoked, but the most hardcore users will inject crack when they can not find powder cocaine to inject.
Crack is the street name given to a freebase form of cocaine that has been processed from the powdered cocaine hydrochloride form to a smokable substance. It is processed with ammonia or sodium bicarbonate (baking soda) and water, and heated to remove the hydrochloride. Crack rocks are white or off-white and vary in size and shape and tend to be sold in sizes of approximately 0.1 to 0.2 grams, which sell for approximately $10 and $20, respectively.
Crack emerged as a drug of abuse in the mid-1980s. It is abused because it produces an immediate high and is easy and inexpensive to produce. Smoking crack cocaine delivers large quantities of the drug to the lungs, producing an immediate and intense euphoric effect, comparable to intravenous injection, but it does not last long. Because crack is smoked, the user experiences a high in less than 10 seconds. The effects of smoking crack are felt almost immediately after smoking and are very intense. For example, the high from smoking cocaine may last from 5 to 10 minutes, while the high from snorting the drug can last for 15 to 20 minutes.
Smoking crack will often cause particularly aggressive paranoid behavior in users. Physical effects of using crack include constricted blood vessels and increased temperature, heart rate, and blood pressure. Users may also experience feelings of restlessness, irritability and anxiety. Evidence suggests that users who smoke cocaine may be at even greater risk of causing harm to themselves than those who snort the substance. Crack users suffer from acute respiratory problems including coughing, shortness of breath, and severe chest pains with lung trauma and bleeding.
Source: Parts reprinted from The National Institute on Drug Abuse (NIDA)