What Dose of Methadone is Lethal?

A dose of 20 mg of methadone may be lethal for one patient and just right for another patient.  How can this be?  The line between the “right” or therapeutic dose of methadone and a lethal or deadly dose of methadone depends on (1) why the patient is using methadone, and (2) whether the patient has been using methadone continuously every day for weeks or months before the dose is given, (3) the health of the patient and (4) whether the dose of methadone is given in the first few days of methadone therapy. Generally speaking, the rule is “Start low and go slow” when dosing methadone. While each patient’s dose should be individualized for that patient, some high doses clearly have the potential to cause death. Any dose for a pain patient above 10 or 20 mg has the potential to cause death. The physician is the only one who can make a decision about what dose is safe. A doctor, however, should not be using a one-size-fits-all dosing strategy. For a patient who is admitted to an opiate treatment program or methadone clinic, a starting dose of 25 or 30 may be lethal, especially if the dose is repeated daily or increased. Only a physician can make the decision about what dose is safe for a patient, but this decision should be individualized. No doctor should be giving the same dose to all or most patients as a matter of routine.