How long does methadone remain detectable in a urine immunoassay?

Methadone can typically be detected in a urine immunoassay for 2-3 days after administration. This timeframe is influenced by several factors, including the dose of methadone, the individual's metabolism, frequency of use, and overall health status. Methadone is a long-acting opioid, and while its primary effects may wear off within 24 hours, it can persist in urine longer due to how the body metabolizes and excretes the drug.

Over time, the metabolites of methadone can accumulate, leading to detection in urine even after the acute effects of the drug have subsided. This characteristic makes it particularly important for clinicians to consider when monitoring patients in treatment programs. The given range of 2-3 days aligns with clinical data on urine testing for methadone, providing a reliable window for detection following use.