What are heroin's short-term effects?

Depending on the route of administration, users may begin to feel a "rush" within 10-15 minutes if snorted or smoked. The "rush begins as a warm flushing of the skin, dry mouth, watery eyes and a runny nose, constricted pupils, and a heavy feeling in the extremities accompanied by nausea, vomiting, and severe itching. The euphoric feelings are followed by drowsiness, clouded mental function or stupor, decreased respiration and heart beat, and feelings of well being that may last four to six hours.