The two main types of analgesics are mild and strong. Although the basic purpose of an analgesic is to prevent and kill pain, these two different types work in quite different ways. Mild analgesics, such as aspirin, intercept the feeling of pain at the source, often altering the production of certain substances in the body that are the cause of the problem. Strong analgesics, such as opium and its derivatives, work by, on a temporary basis, bonding receptor sites to the brain, so the transmission of pain cannot reach the brain. Therefore, we do not have any feeling of the pain. Since the signal of pain does not reach the brain, strong analgesics do not depress the central nervous system. The most well known of all strong analgesics are the opioids, which include opium, morphine, heroin, codeine and numerous other synthetic drugs.
How are mild analgesics used?
The three drugs above are some of the more commonly used strong analgesics. They are all narcotics, derived from opium. As they are all derived from opium, their chemical structures are similar. However, I will now point out some important differences. Morphine and Heroin have much in common chemically, as heroin is a derivative of morphine. The more complex structure of heroin is a cause of its much more extreme effects. Heroin is actually a more effective painkiller than morphine. However, the side effects, such as addiction and the dangers of long-term use, as well as the obvious reasons of abuse, stop it from being used medicinally. Codeine has a slightly different structure than morphine and heroin, due to the effects of codeine that are much milder. Codeine is a common cough suppressant and analgesic used for milder pain.
Morphine and its derivatives can often be vital medical tools, however, there is debate over the potential danger of side effects. Morphine is primarily used medicinally; although there are many cases of it being abused. However, morphine is not free from side effects either, two of the most dangerous being the intense constipation caused and its addictive properties. Morphine users often take laxatives to aid excretion. Morphine, like all narcotics, is very addictive. It also produces feelings of euphoria and intense well-being, which add to this addictive effect. Morphine does not cause that much of a problem as other drugs, like heroin. Heroin is one of the most effective painkillers known to man. Unfortunately, its side effects are enough to stop its medical use. Heroin shares many of the side effects of morphine, but in an extreme form.
Heroin is the most commonly abused drug in many countries. Due to its level of abuse, heroin has been outlawed with strict trafficking penalties in many areas. Heroin abuse gradually leads to dependence, a state where the drug is taken just to feel normal, rather than to achieve the high. After being “stoned” when the high has finished, the addict wants more. This is what makes heroin so dangerous. Heroin abuse has strong effects on society, often making crime increase. There are some advantages to using heroin medicinally, though. In some cases, only heroin will provide the necessary analgesic effect to keep somebody alive. The patient will die eventually from the heroin, but this will be a death free of pain.
To see a full report on the effects of heroin, see this link: www2.health-center.com: About Opiates and Heroin