- Molecular NameDoxepin
- SynonymDoxepin Hcl; Doxepin, Hydrochloride; Doxepina [INN-Spanish]; Doxepine; Doxepinum [INN-Latin]
- Weight281.399
- Drugbank_IDDB01142
- ACS_NO1668-19-5
- Show 2D model
- LogP (experiment)4.29
- LogP (predicted, AB/LogP v2.0)4.13
- pka9.0
- LogD (pH=7, predicted)1.41
- Solubility (experiment)0.111 mg/ml
- LogS (predicted, ACD/Labs)(ph=7)-0.92
- LogSw (predicted, AB/LogsW2.0)0.03
- Sw (mg/ml) (predicted, ACD/Labs)0.14
- No.of HBond Donors0
- No.of HBond Acceptors2
- No.of Rotatable Bonds4
- TPSA12.47
- StatusFDA approved
- AdministrationOral, intramuscular injection, intravenous infusion
- PharmacologyA psychotropic agent with tricyclic antidepressant and anxiolytic properties,
- Absorption_value100.0
- Absorption (description)Well absorbed after oral administration
- Caco_2N/A
- Bioavailability30.0
- Protein binding82.0
- Volume of distribution (VD)24 L/kg
- Blood/Plasma Partitioning ratio (D_blood)Plasma:whole blood ratio, doxepin about 0.8 but there is considerable intersubject variation; monodesmethyldoxepin about 0.6.
- MetabollsmUndergoes extensive first-pass demethylation. Other metabolic reactions include N-oxidation, aromatic hydroxylation, and glucuronic acid conjugation. Monodesmethyldoxepin is an active metabolite.
- Half life18 h, desmethyldoxepin 51 h
- ExcretionDoxepin is excreted in the urine, chiefly as metabolites and conjugated metabolites; less than 1% of a dose is excreted in the urine as unchanged drug in 24 h. It is also absorbed through the skin if applied topically. It crosses the blood–brain barrier and the placenta. Both doxepin and its active metabolite, desmethyldoxepin, are excreted in breast milk.
- Urinary Excretion0
- Clerance14 ml/min/kg
- ToxicityDoses in excess of 500 mg are likely to produce severe toxic effects and the estimated minimum lethal dose is 1 g. Blood concentrations >0.1 mg/L may be associated with toxic reactions and fatalities have been associated with blood concentrations of 1 to 18 mg/L (mean 8).
- LD50 (rat)N/A
- LD50 (mouse)N/A