Both new and experienced users risk overdosing on heroin because it is impossible for them to know the purity of the heroin they are using. (Heroin sold on the street often is mixed with other substances such as sugar, starch, or quinine. An added risk results when heroin is mixed with poisons such as strychnine.) Heroin overdoses--which can result whether the drug is snorted, smoked, or injected--can cause slow and shallow breathing, convulsions, coma, and even death. "Smoking" methamphetamine actually refers to vaporizing it to produce fumes, rather than burning and inhaling the resulting smoke, as with tobacco. It is commonly smoked in glass pipes made from blown Pyrex tubes, light bulbs, or on aluminum foil heated by a flame underneath. This method is also known as "chasing the white dragon". In the United States, possession of more than 100 grams of heroin or a mixture containing heroin is punishable with a minimum mandatory sentence of 5 years of imprisonment in a federal prison. After the initial effects, abusers usually will be drowsy for several hours. Mental function is clouded by heroin's effect on the central nervous system. Cardiac function slows. Heroin facts about its short term effects include severely slowed breathing, sometimes to the point of death. Both first time users and experienced heroin abusers are at risk for overdose because they never know the true purity of the heroin they are using. A heroin overdose can take place if the heroin the user has purchased is stronger than they anticipated or if the drug has been “cut” with a dangerous chemical. | 
