Peak and trough test definition
Peak and trough test means a therapeutic monitoring of serum methadone levels to determine the most appropriate dosing strategy for the individual patient, requiring at least two blood samples be drawn. The initial sample taken immediately prior to the daily dose and twenty four hours after the previous day's dose allowing the lowest level or "trough" to be identified. The second sample taken four hours after dosing allows the highest level or "peak" to be identified.