The route of administration among heroin users entering treatment has been changing. In 1993, 74% of admissions for heroin abuse were injectors. By 1999, this had declined to 66%. There was an increase in admission for heroin inhalation for 23% in 1993 to 28% in 1999. Ecstasy is usually taken by mouth in a pill, tablet, or capsule. These pills can be different colors, and sometimes the pills have cartoon-like images on them. Some ecstasy users take more than one pill at a time, called "bumping." Once in the brain, heroin - similar to other drugs of abuse - causes the release of dopamine, a neurochemical that mediates pleasure and is vital to the normal functioning of the central nervous system. The drugs addictive properties are believed to be related to a chronic and unnatural increase in dopamine levels. In the US, opium was used to treat soldiers during the Civil War (1861-1865). During the late 1800s, doctors prescribed "tonics" containing opiates for many conditions. Rarely did these medicines list opiates as one of the ingredients. In fact, heroin was marketed as a cough medicine and a cure for morphine addiction. However, many physicians had concerns about possible addiction to these medicines. | 
