SDRL offers serum methadone (peak, trough and level) testing so treatment clinics can verify their patients are receiving the correct methadone dosage and/or to confirm that the dosages administered are in fact “holding” properly. Measuring levels of methadone in the blood is helpful in determining how much of the medication is circulating in a patient's system.

• A trough test measures the lowest amount of methadone in a patient’s blood and is measured on a sample drawn just prior to daily dose.


• A peak test measures the highest amount of methadone in a patient’s blood and is the concentration of a serum sample drawn four hours after the dose.

When the trough and the peak values are the same or very similar, the methadone is being absorbed by the patient in the daily dose and distributed uniformly throughout the day.

When the values differ greatly, there is an increased metabolism and excretion by the patient. This may result in a patient's claim of withdrawal. Dose timing and/or increase should be considered as options.

In most cases, peak and trough results are provided within 48-72 hours of receipt and delivered via facsimile, SFTP or posted to SDRL’s client-secure web site for immediate access.

Clients are responsible for their patients’ blood draws (via in-house phlebotomist, nurse, local hospital, etc.). All specimen collection containers, labels and packaging/shipping materials are provided by SDRL. Contact us for more information.

Additional information on serum methadone testing can be found by clicking on the following links: