Methadone is a synthetic opioid with potent analgesic effects. Although commonly associated with the treatment of opioid addiction, analgesia may also be prescribed for various pain syndromes. It may also be an appropriate replacement for morphine, when side effects limit dosage increases. Methadone toxicity is not always apparent in the first few days after initiating therapy and so careful follow up of all patients is mandatory.
Any other medications that the inpidual is taking may interfere with methadone so careful dosing is required. Methadone treatment for pain is a lot cheaper than other long acting morphine formulations
With methadone maintenance, addicts take regular doses of methadone to decrease the withdrawal and cravings that are associated with opioids. It is one of the most successful treatments for heroin addiction. The treatment is also highly cost effective, costing about $5000 per patient, compared to nearly $25,000 to look after a patient with AIDs.
Methadone is classified as a schedule II of the Controlled Substances Act. Initially, its use was limited to "detoxification treatment” or "maintenance treatment” within U.S. Food and Drug Administration approved narcotic addiction programs.
Because of its potency as a pain killer, the DEA has allowed physicians to prescribe it for pain control. However, most states require that a physician document in the chart that methadone is being prescribed for pain control and not treatment of drug addiction. Many hospitals, however, do not have methadone supplies in their pharmacies. All physicians with appropriate Drug Enforcement Agency registration may prescribe methadone for analgesia.
Methadone Prescription Difficulties
Methadone prescriptions for the treatment of drug addiction are not easily available. The prescriptive authority by physicians is highly controlled and monitored. Only a few selected registered physicians have the ability to prescribe the drug and physicians have to make a special application to the FDA and the Drug Enforcement Agency.
The Department of Health & Human Services and the FDA also decide dosage regimens and how, and under what circumstances, methadone maintenance may be used to treat opiate addiction. Most methadone clinics must obtain an extra license and comply with extra set of both federal and state regulations.
All this has made it difficult for opioid addicts to get methadone. Although there are over 700 active methadone clinics in the Nation, many states don’t allow methadone clinics, forcing some patients to drive hundreds of miles each day to get their required daily dosage. Clinics in states that do allow methadone often have strict morning hours that make it difficult for patients to stick to the regimen.
Methadone has been studied as a therapy for cancer pain and other chronic pain. It is an appropriate replacement for opioid when pain remains poorly controlled or when side effects of other opioids limit dosage escalation. Available data suggest that methadone is effective in relieving cancer pain and has a similar analgesic efficacy and side effect profile to morphine.
Methadone can be administered both orally and via injection. When administered for pain control, the onset of analgesia is approximately three to six hours. When methadone therapy is initiated, then this duration typically extends eight to twelve hours with repeated dosing.
When methadone is administered for drug addiction, its slower onset of action and long half-life helps in decreasing the incidence of withdrawal symptoms. In the outpatient setting, methadone dose is slowly increased over 5-7 days, depending on the patient's response. In some opioid tolerant patients, higher doses of methadone may be required over a shorter time.
During the titration phase, daily telephone progress reports by the patient, family members, home health nurses, or hospice personnel are recommended. Patients should be informed that several titrations might be necessary to reach optimal pain control.
In all patients continuous monitoring is required to ensure that withdrawal to opioids is not occurring. The dose can be safely increased in small increments while the patient is in hospital. Transition from high-dosage opioids may have to be completed in an inpatient setting with assistance from a pain specialist.
- Side effects associated with methadone include:
- Respiratory Depression
Excess sweating and flushing are common with oral methadone dosing. Caution should be taken with initiation of therapy and dosage increases because severe toxicities may not become apparent for two to five days. Side effects such as sedation and respiratory depression are increased when methadone is combined with alcohol or other drugs.
Methadone offers a cost savings over standard morphine preparations when used to treat pain. Legislation is being considered to reduce or even eliminate some regulations on methadone providers to make treatment more widely available.
The recent availability of buprenorphine for opioid addiction treatment has brought more optimism to the field of drug addiction. Like methadone, buprenorphine is a replacement therapy. It is easier to withdraw from than methadone however; the risk of it being perted illegally is even lower than for methadone. If it is injected by a would-be abuser (rather than being taken by mouth, as it is intended to be used therapeutically); it causes withdrawal symptoms and not a "high."