Long-term use also can lead to physical dependence—the body adapts to the presence of the substance and withdrawal symptoms occur if use is reduced abruptly. This can also include tolerance, which means that higher doses of a medication must be taken to obtain the same initial effects. Note that physical dependence is not the same as addiction—physical dependence can occur even with appropriate long-term use of opioid and other medications. Addiction, as noted earlier, is defined as compulsive, often uncontrollable drug use in spite of negative consequences.
Individuals taking prescribed opioid medications should not only be given these medications under appropriate medical supervision, but also should be medically supervised when stopping use in order to reduce or avoid withdrawal symptoms. Symptoms of withdrawal can include restlessness, muscle and bone pain, insomnia, diarrhea, vomiting, cold flashes with goose bumps ("cold turkey"), and involuntary leg movements.
Individuals who become addicted to prescription medications can be treated. Options for effectively treating addiction to prescription opioids are drawn from research on treating heroin addiction. Some pharmacological examples of available treatments follow:
- Methadone, a synthetic opioid that blocks the effects of heroin and other opioids, eliminates withdrawal symptoms and relieves craving. It has been used for over 30 years to successfully treat people addicted to opioids.
- Buprenorphine, another synthetic opioid, is a recent addition to the arsenal of medications for treating addiction to heroin and other opiates.
- Naltrexone is a long-acting opioid blocker often used with highly motivated individuals in treatment programs promoting complete abstinence. Naltrexone also is used to prevent relapse. Naloxone counteracts the effects of opioids and is used to treat overdoses.