Final answer:
Heroin was originally introduced as a medication for pain relief and is a modified form of morphine, increased in potency by the chemical alteration of its structure. It is extremely addictive and carries significant health risks, including a high risk of disease transmission and overdose. Methadone can be used to treat heroin addiction due to its ability to reduce cravings and withdrawal symptoms.
Step-by-step explanation:
Heroin was originally introduced as a pain-relief medication and is a chemically altered form of morphine. Morphine is derived from the opium poppy and is a potent analgesic. Codeine, another less potent painkiller, is also derived from the opium poppy. Morphine contains two hydroxyl functional groups, and by chemically modifying these groups, heroin is synthesized. Specifically, converting both hydroxyl groups to esters of acetic acid results in the formation of heroin. This modification greatly increases the compound's potency, which is why heroin is known to be about three times more potent than morphine. Opioids like heroin work by binding to specific receptors in the brain, spinal cord, and gastrointestinal tract, altering the way pain is experienced. While both morphine and codeine are utilized in medicine, the use of heroin is strongly associated with addiction and abuse, leading to serious health risks, including the increased risk for contracting diseases like HIV and tuberculosis as well as likelihood for overdose.