Cocaine can cause brain seizures, a disturbance of the brain's electrical signals, some of which regulate the heart and muscles controlling breathing. Violent, erratic, or paranoid behavior can sometimes accompany use of cocaine, which can occur in all cocaine users, and may appear more rapidly in those who smoke crack. Cocaine used during the early months of pregnancy may cause miscarriages or still births. Later, the drugs may cause premature labor or premature delivery. Sometimes when the drug causes the placenta to separate early, the lives of both mother and baby are in danger due to bleeding and shock.
Nursing mothers can pass on cocaine to their babies through breast milk.
Heroin is the most under-reported drug in terms of usage. Estimates of heroin users range from 428,000 users in the past year to 600,000 users in the past week. Some experts estimate 2-3 million people use heroin recreationally. The average age of heroin addicts seeking treatment has fallen in the past several years, indicating that the age of first usage was in the teenage years. It is the most abused and most rapidly acting of all the opiates.