|
Opioids have a legitimate medical use as powerful pain relievers (see Pain: Opioid Analgesics). They include codeine (which has a low dependence potential), oxycodone (alone and in various combinations, such as oxycodone plus acetaminophen ), meperidine , morphine , pentazocine , and hydromorphone . Heroin, which is illegal in the United States but is used in very limited treatment applications in other countries, is one of the strongest opioids. A person can become dependent on any opioid.
Some people become dependent on opioids after starting their use for appropriate medically prescribed control of pain. Although many people who use opioids for pain relief for more than several days feel some symptoms of withdrawal when they stop, serious dependence and addiction rarely occur when opioid use is medically supervised.
Tolerance can develop after 2 to 3 days of continued opioid use. People who have developed tolerance may show few signs of drug use and function normally in their usual activities as long as they have access to drugs.
Symptoms and
Complications
Opioids have many effects. They are strong sedating drugs and cause people to become quiet and introspective. Opioids may also produce euphoria, sometimes simply because severe pain has finally been relieved. They dull pain and may enhance sexual pleasure. They also cause constipation; flushed or warm skin and lowered blood pressure; itching; constricted pupils; slow, shallow breathing; a slow heart rate; and low body temperature. Opioids may cause confusion, especially in older people.
Many complications can arise from opioid addiction, especially if the drugs are injected with shared unsterilized needles. For example, viral hepatitis, which causes liver damage, can be spread through shared needles. Infections can occur at the site of injection or be carried through the bloodstream (sepsis), causing infections in the brain and bones.
Drug abuser's elbow (myositis ossificans) is caused by repeated, inept needle punctures; the muscle around the elbow is replaced with scar tissue. Subcutaneous injections (skin popping) can cause skin sores. Intravenous injections lead to scarring of veins (tracks), which makes the veins more and more difficult to inject.
Opioid addicts can develop lung problems, such as lung irritations from aspiration (inhaling saliva or vomit), pneumonia, abscesses, pulmonary emboli, and scarring, which can develop from the talc in impure injections. Problems with the immune system can develop. Because the human immunodeficiency virus (HIV) can spread through shared needles, many people who inject opioids also develop AIDS. Needle sharing is now becoming the principal route of HIV infection in the United States.
Opioid addicts can develop neurologic problems, usually as the result of inadequate blood flow to the brain. Coma may result. Quinine, a common heroin contaminant, can cause double vision, paralysis, and other nerve injury symptoms, including Guillain-Barré syndrome (see Peripheral Nerve Disorders: Guillain-Barré Syndrome). A contaminant sometimes present in homemade meperidine (MPTP) damages the brain and leads to severe parkinsonism (see Movement Disorders: Parkinson's Disease).
Drug overdose presents a serious threat to life. Opioids suppress breathing and can cause the lungs to fill with fluid.
Opioid use during pregnancy is especially serious. Heroin and methadone easily cross the placenta into the fetus. A baby born to an addicted mother may quickly develop withdrawal symptoms, including tremors, high-pitched crying, jitters, seizures, and rapid breathing (see Drug Use During Pregnancy: Opioids).
Withdrawal symptoms can appear as early as 4 to 6 hours after the opioid use stops and generally peak within 36 to 72 hours. However, each opioid is eliminated from the body at a different rate, which alters the rate at which withdrawal occurs. The withdrawal symptoms are worse in people who have used large doses for longer times.
The first sign of withdrawal is generally rapid breathing, usually accompanied by yawning, perspiration, crying, and a runny nose. Other signs include hyperactivity, a sense of heightened alertness, rapid breathing, agitation, an increased heart rate, fever, dilated pupils, gooseflesh, tremors, muscle twitching, hot and cold flashes, aching muscles, loss of appetite, abdominal cramps, and diarrhea.
Treatment
Emergency Treatment:
An opioid overdose is a medical emergency that must be treated quickly to prevent death. Breathing may require support, sometimes with a ventilator, if the overdose has suppressed breathing. A drug called naloxone is given intravenously as an antidote to the opioid.
Detoxification and Rehabilitation:
Treatment is usually needed to lessen the symptoms of withdrawal. Symptoms of opioid withdrawal can also be relieved with a drug called clonidine . However, clonidine may cause some side effects, including low blood pressure, drowsiness, restlessness, insomnia, irritability, faster heartbeat, and headaches. Substituting methadone for the opioid provides another treatment for withdrawal. Methadone , itself an opioid, is taken by mouth and alters brain function less than do other opioids. Because methadone 's effects last much longer than those of other opioids, it can be taken less frequently, usually once a day. The dose can then be decreased slowly.
Methadone may also be part of a long-term maintenance treatment program. Maintaining addicts with regular doses of methadone for months or years will enable them to be socially productive because their supply problems are met. For some, the treatment works. Others may not become socially rehabilitated. For many addicts, lifelong methadone maintenance is necessary. Opioid addicts must appear every day at a clinic, where methadone is dispensed in the smallest amount that prevents severe withdrawal symptoms from developing.
A few treatment centers may dispense l-alpha-acetylmethadol (LAAM), a longer-acting form of methadone . This eliminates the need to make daily clinic visits or to take drugs home. Buprenorphine , another maintenance drug, can be prescribed by doctors in their offices. This allows for treatment similar to methadone detoxification or maintenance without having to go to a methadone clinic.
Naltrexone is a drug that blocks the effects of opioids. Depending on the dose, naltrexone 's effects last from 24 to 72 hours. Because of this, an addict who has a stable social background can take this drug daily (or possibly as few as 3 times a week) to avoid the temptation of using opioids.
The therapeutic community concept emerged nearly 25 years ago in response to the problems of heroin addiction. Daytop Village and Phoenix House pioneered this nondrug approach. Treatment involves a communal, relatively long-term (usually 15- to 18-month) stay in a residential setting to help addicts build new lives through training, education, and redirection. These programs have helped many people, but questions about precisely how well they have worked and how widely they should be applied remain unanswered.
The AIDS epidemic has motivated some people to suggest that sterile needles and syringes be provided to addicts who inject opioids intravenously. Such distribution has been shown to reduce HIV transmission.
Last full review/revision February 2003
| 
