Methadone is a drug commonly used to treat both chronic pain and opioid addiction with the latter representing the most commonly prescribed usage. Due to the high risk of developing a chemical dependency associated with all high potency pain medications, there must be considerable care given by a physician in determining the correct methadone dosage.
When treating pain, if treating an adult with oral methadone one should always start with a low dosage and increase the dose until the patient achieves adequate pain relief. Generally one starts with a dose of 2.5 mg and then gradually increases up to 10 mg, with a frequency of administration of roughly 10 hours.
The physician needs to remember that the drug persists for a long time in the blood stream so one should not increase the dose too rapidly. Intravenous and intramuscular applications of the drug should be titrated using a similar dosage and methodology.
If, on the other hand, a person is being treated for opioid dependency, one will usually need to start at a higher dose and gradually withdraw the medicine. Generally the right starting dose is between 15 and 40 mg depending on the severity of the addiction. In some severe cases patients have been treated with as much as 325 mg per day. Dosage might thus need to be elevated over a number of days until withdrawal symptoms stabilize. The frequency of administration is generally daily, although one can give an additional 5 to 10 mg if the patient is experiencing severe withdrawal symptoms that cannot be tolerated.
After a couple of days stabilization at this base methadone dosage, the physician can begin to lower the dosage down slowly, roughly by a fifth per day until the patient is able to go without being medicated. This is generally achievable within 10 days.
Care must always be exercised in determining the correct methadone dosage as different people will respond differently based on their genetics and tolerance to the drug. This is particularly true in the case of treating severe opioid dependencies where a patient could have a very abnormal tolerance for the drug.