Title: Doxepin
CAS Registry Number: 1668-19-5
CAS Name: 3-Dibenz[b,e]oxepin-11(6H)-ylidene-N,N-dimethyl-1-propanamine
Additional Names: N,N-dimethyldibenz[b,e]oxepin-D11(6H),g-propylamine; 11-(3-dimethylaminopropylidene)-6,11-dihydrodibenz[b,e]oxepin
Manufacturers' Codes: P-3693A
Molecular Formula: C19H21NO
Molecular Weight: 279.38
Percent Composition: C 81.68%, H 7.58%, N 5.01%, O 5.73%
Literature References: Prepn of mixture of cis- and trans-isomers: K. Stach, F. Bickelhaupt, Monatsh. Chem. 93, 896 (1962); F. Bickelhaupt et al., ibid. 95, 485 (1964); NL 6407758; K. Stach, US 3438981 (1965, 1969 both to Boehringer Mann.); and separation and activity of isomers: B. M. Bloom, J. R. Tretter, BE 641498; eidem, US 3420851 (1964, 1969 both to Pfizer). Pharmacology: A. Ribbentrop, W. Schaumann, Arzneim.-Forsch. 15, 863 (1965). Metabolism in animals: D. C. Hobbs, Biochem. Pharmacol. 18, 1941 (1969). Determn in plasma by GC/MS: T. P. Davis et al., J. Chromatogr. 273, 436 (1983); by HPLC: T. Emm, L. J. Lesko, ibid. 419, 445 (1987). Clinical study in depression: K. Rickels et al., Arch. Gen. Psychiatry 42, 134 (1985). Comparative clinical trial with cimetidine, q.v., in treatment of ulcer: R. K. Shrivastava et al., Clin. Ther. 7, 181 (1985). Review of pharmacology and therapeutic efficacy: R. M. Pinder et al., Drugs 13, 161 (1977).
Properties: Oily liq consisting of a mixture of cis- and trans-isomers. bp0.03 154-157°, bp0.2 260-270°. LD50 in mice, rats (mg/kg): 26, 16 i.v.; 79, 182 i.p.; 135, 147 orally (Ribbentrop, Schaumann).
Boiling point: bp0.03 154-157°; bp0.2 260-270°
Toxicity data: LD50 in mice, rats (mg/kg): 26, 16 i.v.; 79, 182 i.p.; 135, 147 orally (Ribbentrop, Schaumann)
Derivative Type: Hydrochloride
CAS Registry Number: 1229-29-4
Trademarks: Adapin (Lotus); Aponal (Boehringer, Mann.); Curatin (Pfizer); Quitaxon (Boehringer, Mann.); Sinequan (Pfizer)
Molecular Formula: C19H21NO.HCl
Molecular Weight: 315.84
Percent Composition: C 72.25%, H 7.02%, N 4.43%, O 5.07%, Cl 11.22%
Properties: Crystals, mp 184-186°, 188-189°.
Melting point: mp 184-186°, 188-189°
Derivative Type: Maleate
Properties: Crystals, mp 161-164°, 168-169°.
Melting point: mp 161-164°, 168-169°
Derivative Type: trans-Form hydrochloride
CAS Registry Number: 3607-18-9
Properties: mp 192-193°.
Melting point: mp 192-193°
Derivative Type: cis-Form hydrochloride
CAS Registry Number: 25127-31-5
Additional Names: Cidoxepin hydrochloride
Manufacturers' Codes: P-4599
Properties: Crystals, mp 209-210.5°.
Melting point: mp 209-210.5°
Therap-Cat: Antidepressant.
Therap-Cat-Vet: Antipruritic.
Keywords: Antidepressant; Tricyclics.
Doxercalciferol Doxifluridine Doxofylline DPQ D-Psicose

Systematic (IUPAC) name
Clinical data
Trade names Sinequan, Zonalon
AHFS/ monograph
MedlinePlus a682390
Licence data US FDA:link
Pregnancy cat. C (AU)
Legal status Prescription Only (S4) (AU) -only (CA) POM (UK) -only (US)
Routes Oral, topical, intravenous, intramuscular[1]
Pharmacokinetic data
Protein binding 76%[2]
Metabolism Hepatic (CYP2D6-, CYP2C19-, CYP1A2- & CYP3A4-mediated)[3][4]
Half-life 8-24 hr (mean 17 hours); 31 hr for active metabolite, desmethyldoxepin[2]
Excretion Urine
CAS number 1668-19-5 YesY
ATC code N06AA12
PubChem CID 3158
IUPHAR ligand 1225
DrugBank DB01142
ChemSpider 3046 YesY
KEGG D07875 YesY
Chemical data
Formula C19H21NO 
Mol. mass 279.376 g/mol
 N (what is this?)  (verify)

Doxepin (brand names of oral formulations include Deptran, Sinequan. Whereas brand names of topical (cream) formulations include Prudoxin) is a tricyclic antidepressant that is marketed worldwide, including Australia, Canada, New Zealand, South Africa, the United Kingdom and the United States of America.[1]