Cocaine's effects appear almost immediately and disappear in a few minutes or hours, depending on the route of administration. Injected and smoked cocaine produces intense effects rapidly. Small amounts make the user feel euphoric, energetic, talkative, and alert. Large amounts intensify these feelings but may lead to bizarre, erratic, and violent behavior. Physiological effects include constricted blood vessels, dilated pupils, and increased temperature, heart rate, and blood pressure.
Some users report feelings of restlessness, irritability, and anxiety.
In rare instances, sudden death can occur, usually from cardiac arrest followed by respiratory arrest. Cardiovascular effects include disturb-ances in heart rhythm and heart attacks. Respiratory effects include chest pain and respiratory failure. Strokes, seizures, and headaches are among the neurological effects. Gastrointestinal complications include abdominal pain and nausea.