Opioid analgesics are all chemically related to morphine, a natural substance extracted from poppies, although some are extracted from other plants and others are produced in a laboratory. Although opioid analgesics are very effective in controlling pain they have drawbacks when used long term. Continuous use may require increased dosage in time, while stoppage in use may require a tapering off in dosage to limit withdrawal symptoms.
Opioids are classified as narcotic drugs and have the potential for abuse - necessitating the use and prescription of these medications to be regulated by international treaties and national drug control policies. Despite these drawbacks, patients with severe pain should not avoid opioids. When used appropriately, side effects could be minimized or avoided.
Different opioid analgesics have different advantages and disadvantages. Morphine, the prototype of these drugs, is available in many forms. Injectable morphine is still standard issue for combat casualties among armed forces of developed countries, and in emergency rooms in these countries. Immediate-release tablets last 3-4 hours, while sustained-release tablets last 12 hours. Morphine is recommended by the World Health Organization (WHO) not only because of its proven safety and efficacy, but also because it is considerably cheaper than other strong opioids.
Opioid analgesics often cause constipation, especially in older people. Laxatives, usually stimulate laxatives such as senna or phenolphthalein, may help prevent or treat constipation.
There is still a lot of unfounded fear about the side effects of morphine, particularly nausea and sleepiness. These occur in only about a third of patients and disappear in a couple of days. The much feared possibility of addiction is an overblown myth. In reality, documented cases of addiction following the medical use of morphine is quite rare.
One of the most important parameters that the WHO used to gauge the adequacy of pain relief in each country is the average daily morphine consumption in defined daily doses per million inhabitants. In the period 1994-1998, the figures were 6,993, 3,472 and 2,310 for Denmark, Sweden and the United States respectively, and only 88, 60, and 14 for Singapore, Malaysia and the Philippines respectively.
The severe underutilization of morphine in the Philippines has been consistently attributed to the persistence of myths regarding addiction and side effects, as well as the highly restrictive rules and regulations such as the use of official triplicate yellow prescription.
Opioid analgesics are usually recommended for patients after surgery, for patients with cancer pain, and even those suffering from AIDS. Dr. Adriano Laudico, a noted surgeon, believes that in treating pain, it is vital that the proper medicines be prescribed. For serious and extreme levels of pain, particularly that which is experienced right after surgery, Dr. Laudico recommends a combination of an Opioid (Morphine) and Non-Opioid like rofecoxib to help alleviate the patient's discomfort. This, he said, has proven to be very effective particularly during the first 24 to 48 hours after major operations.
For comments and insights, please write to Pain Management Information Agency (PMIA) P.O. Box 3485 Makati, fax 892-3968 or e-mail at paincare@pmia.com.ph. PMIA was established primarily to increase public awareness and understanding of pain and to recommend appropriate medical and practical ways to manage and control pain.