{"hq_id":"hq-c-org-000211","name":"Methadone","context":"human_adult","risk_level":"high","schema":"legacy","note":"Synthesis unavailable: compound lacks vectorizable regulatory classifications. Raw safety data returned.","data":{"risk_level":"high","summary":"Methadone is a full mu-opioid receptor agonist with a distinctive pharmacological profile: extremely long and variable half-life (8–59 hours, mean approximately 24–36 hours, range 5–150 hours), QTc interval prolongation (via hERG potassium channel blockade — Torsades de Pointes risk), and significant drug-drug interactions via CYP3A4 and CYP2D6. FDA-approved for OUD treatment (methadone maintenance treatment, MMT — federally regulated through certified opioid treatment programs) and severe pain. Methadone is effective for OUD treatment and strongly associated with reduced mortality; however, its long, unpredictable half-life creates unique overdose dangers: overdose can occur many hours after the last dose as plasma levels continue to rise ('stacking') and rescue breathing requirements extend beyond initial naloxone doses (repeated naloxone dosing or infusion required). Methadone is disproportionately involved in opioid overdose deaths relative to its prescription volume — approximately 1% of opioid prescriptions but involved in approximately 20% of opioid overdose deaths in 2020, primarily in pain prescribing contexts. QTc prolongation mandates baseline and follow-up ECG monitoring and caution with QTc-prolonging co-medications.","source_refs":["samhsa_methadone_otp_regulations","cdc_methadone_prescribing","echa-chem-reach-registrations","r60-2026-09-30-d918-oehha-prop65-list-csv-own-url","r60-2026-10-02-d-955-s9-d955-s9-osha-table-z-1","src_pubchem_tox_4095","ctx_pred_dtxsid7023273"]},"meta":{"synthesis_version":"n/a","timestamp":"2026-10-28T19:00:02.384Z"},"_notice":"ALETHEIA output is reference data, not professional advice. Not a substitute for primary agency sources or qualified professionals. See https://aletheia.holisticquality.io/disclaimer.","_disclaimer_url":"https://aletheia.holisticquality.io/disclaimer","available_contexts":["human_adult","human_child","dog","human_teen","human_elderly","human_infant","human_pregnant","aquatic_life","exposure_dermal","exposure_inhalation","exposure_ingestion","exposure_ocular","occupational_exposure"]}