- Molecular NameMethadone
- Synonym(+/-)-Methadone; (+/-)-Methadone hydrochloride; dl-Methadone; DL-Methadone hydrochloride; Methadon; Methadone HCL; Methadone hydrochloride; Phenadone hydrochloride
- Weight309.453
- Drugbank_IDDB00333
- ACS_NO76-99-3
- Show 2D model
- LogP (experiment)3.93
- LogP (predicted, AB/LogP v2.0)4.23
- pka8.94
- LogD (pH=7, predicted)2.54
- Solubility (experiment)0.0485 mg/ml
- LogS (predicted, ACD/Labs)(ph=7)-1.76
- LogSw (predicted, AB/LogsW2.0)0.05
- Sw (mg/ml) (predicted, ACD/Labs)0.07
- No.of HBond Donors0
- No.of HBond Acceptors2
- No.of Rotatable Bonds7
- TPSA20.31
- StatusFDA approved
- AdministrationOral, intravenous, insufflation, sublingual, rectal
- PharmacologyA synthetic opioid, used medically as an analgesic, antitussive and a maintenance anti-addictive for use in patients on opioids.
- Absorption_value80.0
- Absorption (description)Methadone is well absorbed from the gastrointestinal tract and can be detected in plasma within 30 minutes after oral ingestion; it reaches peak concentrations at about 4 hours.
- Caco_2N/A
- Bioavailability92.0
- Protein binding89.0
- Volume of distribution (VD)3.6 L/kg
- Blood/Plasma Partitioning ratio (D_blood)N/A
- MetabollsmMethadone undergoes extensive biotransformation in the liver. The major metabolites, the results of N-demethylation and cyclization to form pyrrolidines and pyrroline, are excreted in the urine and the bile along with small amounts of unchanged drug.
- Half life27 h
- ExcretionUrine, Test by specific gravity and bilirubin
- Urinary Excretion24
- Clerance1.7 ml/min/kg
- ToxicityN/A
- LD50 (rat)N/A
- LD50 (mouse)N/A