Methadone is a synthetic opioid used for analgesia and in opiate replacement programs, also called methadone clinics. Methadone is a central nervous system depressant. Methadone toxicity occurs when the load of methadone in a person’s system, is so great that it slows down the respiratory drive—the drive to breathe.
Thousands of patients die each year in every state from methadone toxicity, because methadone can have a long half life. This means that the time it takes for a patient to eliminate half of the methadone from his body may be as long as 100 hours. If a person has a slow metabolism of methadone, and takes several days to eliminate just half of it, then repeated dosing on a daily basis can lead to a toxic, or poisonous buildup. If patients are not tolerant to methadone, a dose of 20 milligrams can be toxic. In the past, many new patients to methadone clinics were given 40 milligrams of methadone on the first day. This proved to be a toxic dose for some patients. Many of these patients were given escalating doses on subsequent days, which increased their methadone load. The federal government has warned clinics about dangerous practices of starting doses too high, or giving every patient the same starting dose.
In pain clinics, recommended dosing begins at 2.5 milligrams, every 6-8 hours.