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The Food and Drug Administration (FDA) is warning consumers and health professionals that methadone use for pain control may result in death and life-threatening changes in breathing and heart beat.
The warning, announced in a November 27, 2006, FDA public health advisory, was issued after the FDA received reports of death and serious respiratory and cardiovascular adverse events associated with the use of this drug. These adverse events are the possible result of unintentional methadone...
The Food and Drug Administration (FDA) is warning consumers and health professionals that methadone use for pain control may result in death and life-threatening changes in breathing and heart beat.
The warning, announced in a November 27, 2006, FDA public health advisory, was issued after the FDA received reports of death and serious respiratory and cardiovascular adverse events associated with the use of this drug. These adverse events are the possible result of unintentional methadone overdoses, drug interactions and inherent heart toxicities from methadone.
Methadone is used in people who have become dependent on narcotics such as heroin to help manage or break their addiction. These reports, however, occurred in patients newly starting methadone for pain control and in patients who have switched to methadone after being treated for pain with other strong narcotic pain relievers such as oxycodone (OXYCONTIN) and morphine (MS CONTIN).
In 2005, the number of prescriptions dispensed for the form of methadone that is most often used for pain management exceeded 1.3 million, up 14.9 percent from 2004.
The professional product label, also known as a package insert, for methadone carries a black-box warning about respiratory depression and fatal heart rhythm disturbances. That warning accompanies this article. A black-box warning is the strongest type of warning that the FDA can request from a drug manufacturer and is usually reserved for those drugs that have caused death or serious injury to patients.
The FDA indicated in its public health advisory that a medication guide is being planned for methadone. The FDA can mandate the distribution of medication guides for drugs that are deemed to present significant public health risks. This written information is approved by the agency and must be distributed with each new prescription or refill by a pharmacist.
The full text of the FDA’s public health advisory is available on the agency’s Web site at http://www.fda.gov/cder/drug/advisory/methadone.htm.
Life-Threatening Adverse Events
The breathing difficulties and heart rhythm disturbances that can result from using methadone occur because the drug remains in a patient’s system even after the drug’s pain-relieving effects wear off. As a result, patients may feel the need for more pain relief before methadone is eliminated from the body. This means that remaining methadone from previous dose(s) are still present in the body. If a patient increases dosage, methadone may then build up in the body to toxic levels, causing breathing difficulties, heart rhythm disturbances and sometimes death.
Patients experiencing any of the symptoms of methadone toxicity listed below should seek medical attention as soon as possible:
- Trouble breathing
- Extreme drowsiness and slowed breathing
- Slow, shallow breathing (little chest movement with breathing)
- Accelerated or slowed heartbeat
- Feeling faint, very dizzy, confused, having heart palpitations (irregular heartbeat) or any other unusual symptoms
What You Can Do
You must take methadone exactly as prescribed. Do not change your dose of methadone without first consulting the prescriber.
Because methadone has some of the effects of other narcotics, do not stop the drug without consulting the prescriber because of the possibility of serious and uncomfortable withdrawal symptoms.
| FDA BLACK BOX WARNING Deaths, cardiac and respiratory, have been reported during initiation and conversion of pain patients to methadone treatment from treatment with other opioid agonists. It is critical to understand the pharmacokinetics of methadone when converting patients from other opioids. Particular vigilance is necessary during treatment initiation, during conversion from one opioid to another, and during dose titration. Respiratory depression is the chief hazard associated with methadone hydrochloride administration. Methadone’s peak respiratory depressant effects typically occur later and persist longer than its peak analgesic effects, particularly in the early dosing period. These characteristics can contribute to cases of iatrogenic [physician-caused] overdose, particularly during treatment initiation and dose titration. In addition, cases of QT interval prolongation and serious arrhythmia (torsades de pointes) have been observed during treatment with methadone. Most cases involve patients being treated for pain with large, multiple daily doses of methadone, although cases have been reported in patients receiving doses commonly used for maintenance treatment of opioid addiction. Methadone treatment for analgesic therapy in patients with acute or chronic pain should only be initiated if the potential analgesic or palliative care benefit of treatment with methadone is considered and outweighs the risks. |
