Opiates

The opiates are derived from a naturally occurring substance, morphine, which comes from a specific variety of the poppy plant. There are naturally occurring opiates such as morphine and heroin and synthetically produced ones such as meperidine (Demerol) and propoxyphene (Darvon). As we've learned, there are also opiate-like substances called endorphins that are produced naturally in the brain. Opiates have a number of diverse actions in the body. In addition to pain relief, they provide a sense of euphoria and relaxation. This effect may be more pronounced in people who are addicted or who are at risk genetically for addiction.

There are also people who feel uncomfortable and uneasy when using opiates for pain relief. This constitutional difference is intriguing, and probably reflects differences in the genetic vulnerability to addiction to these drugs.

Opiates suppress the cough reflex and therefore are found in many cough preparations. They decrease the motility of the gastrointestinal tract and have a pharmaceutical use as a treatment for diarrhea. Opiates also cause the pupils to become constricted, provoke nausea, and are involved in the regulation of body temperature.

The pain-relieving effects of opiates have been appreciated for thousands of years; addiction to them has most likely been a problem for at least as long. When the brain is exposed to opiates such as morphine, physical tolerance and dependence develop, even at very low doses. It has been shown, for example, that hospital patients who are given even small doses of opiate medications for acute pain have a "mini" withdrawal syndrome even after the first dose. This does not mean that the patient has an addiction to opiates. It does mean that the brain reacts very quickly and strongly to the potentially addictive effects of these drugs. And, as with the benzodiazepines, a person can have a physiological dependence on an opiate drug because of medical use without becoming an addict. This is because there is more to addiction that just the body's reaction to the drug; behavioral, psychological, and spiritual factors play a role as well. Supervised medical detoxification from long-term use of opiate analgesics for acutely painful conditions such as burns will correct any physiological dependence. Continuing someone on opiate analgesics when physiological dependence exists is appropriate if the pain cannot be managed in any other way, as, for example, with cancer.

I generally see two types of opiate addiction. The first is heroin addiction, which was widespread in the sixties and seventies, dropped off during the crack cocaine epidemic in the eighties, and is coming back at the turn of the century.

Heroin is a simple derivative of morphine which is not active when taken orally. In the past, it was typically injected intravenously (mainlined). We are now seeing people addicted to smoking or snorting heroin. They are able to avoid the risk of AIDS associated with dirty needles, but the addiction to the heroin is no less severe.