Analgesics, Opioid Health Article

Definition

Opioid analgesics, also known as narcotic analgesics, are pain relievers that act on the central nervous system. Like all narcotics, they may become habit-forming if used over long periods.

Purpose

Opioid analgesics are used to relieve pain from a variety of conditions. Some are used before or during surgery (including dental surgery), both to relieve pain and to make anesthetics work more effectively. They may also be used for the same purposes during labor and delivery.

Description

Opioid analgesics relieve pain by acting directly on the central nervous system. However, this can also lead to unwanted side effects, such as drowsiness, dizziness, breathing problems, and physical or mental dependence.

Among the drugs in this category are codeine; propoxyphene (Darvon); propoxyphene and acetaminophen (Darvocet N); meperidine (Demerol); hydromorphone (Dilaudid); morphine; oxycodone; oxycodone and acetaminophen (Percocet, Roxicet); and hydrocodone and acetaminophen (Lortab, Anexsia). These drugs come in many forms—tablets, syrups, suppositories, and injections—and are sold only by prescription. For some, a new prescription is required for each new supply; refills are prohibited, according to federal regulations.

Recommended dosage

Recommended doses vary, depending on the type of opioid analgesic and the form in which it is being used. Doses may be different for different patients. The person should check with the physician who prescribed the drug or the pharmacist who filled the prescription for correct dosages, and to understand how to take the drug.

A patient should always take opioid analgesics exactly as directed. Larger or more frequent doses should never be taken, and the drug should not be taken for longer than directed. The person should not stop taking the drug suddenly without checking with the physician or dentist who prescribed it. Gradually tapering the dose may reduce the risk of withdrawal symptoms.

For pain following major surgery, it is common practice to give narcotic analgesics by intravenous injection for the first 24–48 hours. This may be followed by oral narcotics for the next 24–48 hours, and then non-narcotic analgesics.

Many hospitals use patient-controlled analgesia (PCA), a system in which the analgesics are given intravenously (by vein), and the patient can control the dose by pushing a button on a pump. This system lets the patient have more control over the amount of medication needed to relieve pain, and eliminates the anxiety that comes from expecting the return of pain when the dose wears off.

Precautions

Anyone who uses opioid analgesics—or any narcotic—over a long time may become physically or mentally dependent on the drug. Physical dependence may lead to withdrawal symptoms when the person stops taking the medicine. Building tolerance to these drugs is also possible when they are used for a long period. The need for larger and more frequent doses is due to enzyme induction, in which narcotics are metabolized by the liver and changed to a form that can be eliminated from the body. The metabolism of narcotics relies on enzymes that are produced by the liver. As narcotics are used, the liver produces more and more of these enzymes, so that a dose of pain medication is removed from the body more rapidly. This is not a problem when narcotics are used for surgical pain, since this type of pain only lasts for a short time.

Opiod analgesics should be taken exactly as directed. It is not advised to take more than the recommended dose, or more often than directed. If the drugs do not seem to be working, the physician should be consulted. These drugs (or any other prescription drugs) should never be shared with others because the drug may have a completely different effect on different people.

Children and older people are especially sensitive to opioid analgesics and may have serious breathing problems after taking them. Children may also become unusually

restless or agitated when given these drugs. These problems can be controlled by adjusting the dose of medication to a safer level.

Opioid analgesics increase the effects of alcohol. Anyone taking these drugs should not drink alcoholic beverages. Some of these drugs may also contain aspirin, caffeine, or acetaminophen. A person should refer to the entries on each of these drugs for additional precautions.