The opiates are found in a gummy substance extracted from the seed pod of the Asian poppy, Papaver somniferum. Opium is produced from this substance, and codeine and morphine are derived from opium.
Other drugs, such as heroin, are processed from morphine or codeine. Opiate-related synthetic drugs, such as meperidine and methadone, are called opioids.
Forms and Appearance
Opium appears either as dark brown chunks or in powder form, and is generally eaten or smoked. Heroin usually appears as a white or brownish powder, which is dissolved in water for injection. Most street preparations of heroin contain only a small percentage of the drug, as they are diluted with sugar, quinine, or other drugs and substances. Other opiate analgesics appear in a variety of forms, such as capsules, tablets, syrups, elixirs, solutions, and suppositories.
Medical and Other Uses
Opiates and their synthetic counterparts (opioids) are used in modern medicine to relieve acute pain suffered as a result of disease, surgery, or injury; in the treatment of some forms of acute heart failure; and in the control of moderate to severe coughs or diarrhoea. They are not the desired treatment for the relief of chronic pain, because their long-term and repeated use can result in drug dependence and side effects (such as constipation and mood swings). They are, however, of particular value in control of pain in the later stages of terminal illness, where the possibility of dependence is not a significant issue.
A small proportion of people for whom the drugs have been medically prescribed become dependent; they are referred to as ‘medical addicts’. Even use of non-prescription codeine products, if continued inappropriately, may get out of control. Medical advice should be sought, since withdrawal symptoms may result from abruptly stopping use after physical dependence has been established. Because members of the medical and allied health professions have ready access to the drugs, some become dependent.
The Federal Narcotic Control Act regulates the possession and distribution of all opiates and opioids. The act permits individual physicians, dentists, pharmacists, and veterinarians, as well as hospitals, to keep supplies of certain drugs. Members of the general public must obtain these drugs from such authorised sources. Although the act also permits the prescribing of methadone in the treatment of heroin dependence, permission is given only to specially licensed physicians, and use is governed by specific guidelines.
Opiates have been used both medically and non-medically for centuries. A tincture of opium called laudanum has been widely used since the 16th century as a remedy for ‘nerves’ or to stop coughing and diarrhoea.
By the early 19th century, morphine had been extracted in a pure form suitable for solution. With the introduction of the hypodermic needle in the mid-19th century, injection of the solution became the common method of administration.
Heroin (diacetylmorphine) was introduced in 1898 and was heralded as a remedy for morphine addiction. Although heroin proved to be a more potent painkiller (analgesic) and cough suppressant than morphine, it was also more likely to produce dependence.
Of the 20 alkaloids contained in opium, only codeine and morphine are still in widespread clinical use today. In this century, many synthetic drugs (opioids) have been developed with essentially the same effects as the natural opium alkaloids. These opiate-related synthetic drugs, such as meperidine (Demerol) and methadone, were first developed to provide an analgesic that would not produce drug dependence. Unfortunately, all opiates and opioids, while effective as analgesics, can also produce dependence. Modern research has led, however, to the development of other families of drugs. The narcotic antagonists (e.g. naloxone hydrochloride) – one of these groups – are used not as painkillers but to reverse the effects of opiate overdose.
(Note that where a drug name is capitalized, it is a registered trade name of the manufacturer.)
Another group of drugs has both morphine-like and naloxone-like properties (e.g. pentazocine, or Talwin) and these are sometimes used for pain relief because they are less likely to be abused and to cause addiction. Nevertheless, abuse of pentazocine in combination with the antihistamine tripelennamine (Pyribenzamine) was widely reported in the 1980s, particularly in several large cities in the United States. This combination became known on the street as “Ts and blues.” The reformulation of Talwin, however, with the narcotic antagonist naloxone has reportedly reduced the incidence of Ts and blues use.