Other additives can include procaine and benzocaine, which are anesthetics, or even small amounts of poisonous hallucinogens such as rat poison. Cocaine in powder form is usually sniffed into the nostrils, however it may also be rubbed into the mucous lining of the mouth. Sometimes users inject cocaine to experience its effects more quickly and to heighten the intensity of the high. The effects of cocaine appear soon after a single dose and disappear within a few minutes or hours. .
Taken in small amounts, cocaine usually makes the user feel euphoric, energetic, talkative, and mentally alert. It can also temporarily hide the body's need for food and sleep. In some users, however, this same small amount may make them feel completely different. These individuals may feel anxious, nauseous, and in some cases even panic-stricken. Still other users find that the drug helps them perform simple physical and intellectual tasks more quickly. The physical symptoms are usually an increased heart rate and breathing, as well as higher than normal blood pressure and body temperature. Taken in large amounts, as often heavy users do, bizarre and erratic behavior can result. These users may experience tremors, vertigo, muscle twitches, or paranoia. These higher doses can bring on such physical symptoms as chest pain, nausea, blurred vision, fever, muscle spasms, convulsions, and coma. Death from a cocaine overdose is often the result of convulsions, heart failure, or respiratory failure. After repeated use, cocaine addicts experience the long term effects of the drug. The euphoria experienced when the user first took the drug is replaced with restlessness, excitability, insomnia, and paranoia (Hyde 1986). Eventually hallucinations and delusions are even possible. Some physical effects of long-term use include stuffiness, runny nose, and a perforated nasal septum. Users who inject the drug risk not only overdosing but also infections from contaminated needles and hepatitis or AIDS.