Methadone has been traditionally used as a drug to treat heroine addiction. In the last few years, it has gained importance as an agent in the treatment of chronic pain.
As a result of this, the US Food and Drug administration has started a campaign to raise awareness about the potential risks of using methadone as a chronic pain medication. In a recent video, the agency lists a number of steps elaborated by the Institute for Safe Medication Practices to help preventing an overdose when using methadone as chronic pain treatment.
• When prescribing methadone for pain, avoid concomitant use of other narcotics, benzodiazepines, and sedatives, because these significantly increase the risk of an adverse event. Prescribe oral liquid doses of methadone in mg, never in mL alone, since several concentrations exist. Include the indication for use when prescribing methadone, to avoid confusion with methylphenidate. Specify the exact time(s) for administration. If the daily dose is taken in the evening one day and then in the morning the next day, this could lead to an overdose.
• When dispensing methadone, use commercially available methadone solutions to prevent compounding errors. Stock only one concentration of oral liquid methadone in the pharmacy, if possible. Accept orders for methadone only when the dose is prescribed in mg. Label all unit-doses with the exact dose, including strength and total volume if it is a liquid, along with the date and time for administration.
• When administering methadone, adhere to standard medication administration times. If a dose is missed, check with the physician before administering it later than originally scheduled. Make sure a pharmacist has reviewed the order before giving the medication to the patient.
• Remind patients to take methadone exactly as prescribed. Instruct them not to start or stop taking any other medications or dietary supplements without talking to their prescriber, because methadone interacts with many other drugs.
• Instruct methadone patients to seek medical attention if they experience symptoms of overdose, such as slow or shallow breathing and extreme sleepiness, or symptoms of arrhythmia.
In a related document, Pain-Topics.org gives a practitioner’s guide to the dosing of oral methadone.