Cocaine is a powerful stimulant that is used legally as a local anesthetic for some eye, ear, and throat surgeries. Cocaine is also called coke, C, snow, flake, or blow. It may contain other substances, such as cornstarch, talcum powder, or sugar. It may also contain other drugs, such as another local anesthetic called procaine or a stimulant such as amphetamine.

Two forms of cocaine are abused.

• The white crystalline powdered form can be sniffed through the nose (snorted) or dissolved in water and taken through a vein (intravenously, or IV). It can also be taken by mouth or rubbed onto the gums.
• The freebase form, which has had impurities removed with solvents, is smoked. Crack is a smokable, freebase cocaine made from powdered cocaine hydrochloride. It is also called chips, chunks, or rocks. The name crack came about because of the crackling sound that it makes when it is smoked.

Small amounts of cocaine make a person feel euphoric, energetic, talkative, and mentally alert. It also decreases appetite and the need for sleep. When large amounts of cocaine are taken, the high is more intense. However, large doses can cause strange or violent behavior in which the person may have tremors or muscle twitches or become paranoid.

After using cocaine, the person feels irritable, tired, and depressed. This is called a coke crash. When a person takes the drug at higher and higher doses (a binge), it can cause increasing irritability, restlessness, and paranoia that can result in a serious loss of touch with reality (paranoid psychosis).

Cocaine is a very addictive drug, and some people easily lose control over its use.

Use of cocaine can lead to serious health problems, including:

• Changes in heart rhythm and heart attack.
• Headache, seizure, and stroke.
• Loss of smell, persistent runny nose, nosebleeds, hoarseness, and destruction of the nasal separation (nasal septum) when the drug is snorted.
• Bowel tissue death.
• Serious infections, HIV, hepatitis, or allergic reactions when injected into a vein.
• Weight loss and poor nutrition from loss of appetite.

Occasionally, sudden death can occur, even with the first use of cocaine. Sudden death from cocaine use may occur because of a heart attack or seizure in which breathing stops. Sudden death is more likely to occur when cocaine is used along with alcohol.

The effects of cocaine last about 1 to 2 hours. Cocaine can be detected in a urine drug screen up to 6 days after it has been taken.

Signs of use

• Possession of drug paraphernalia, such as syringes, spoons with smoke stains, small pieces of glass, and razor blades
• Persistent runny nose and nosebleeds, which may indicate snorting of cocaine
• "Track marks" where it has been injected into veins
• Long periods of time without sleeping or eating