Title: Dichloralphenazone
CAS Registry Number: 480-30-8
CAS Name: 1,2-Dihydro-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one compd with 2,2,2-trichloro-1,1-ethanediol(1:2)
Additional Names: dichloralantipyrine
Trademarks: Bonadorm (Smith & Nephew); Dormwell (Smith & Nephew); Welldorm (Smith & Nephew)
Molecular Formula: C15H18Cl6N2O5
Molecular Weight: 519.03
Percent Composition: C 34.71%, H 3.50%, Cl 40.98%, N 5.40%, O 15.41%
Line Formula: [CCl3CH(OH)2]2.C11H12N2O
Literature References: Prepn: Pfeiffer, Seidel, Z. Physiol. Chem. 178, 97 (1928). GLC determn in pharmaceutical formulation: F. M. Plakogiannis, A. M. Saad, J. Pharm. Sci. 66, 604 (1977). Clinical trial of combination with isometheptene and acetaminophen, q.q.v., in treatment of migraine: S. Diamond, Headache 15, 282 (1976).
Properties: Small prismatic needles from water, mp 68°.
Melting point: mp 68°
NOTE: This is a controlled substance (depressant): 21 CFR, 1308.14.
Therap-Cat: Sedative, hypnotic.
Keywords: Sedative/Hypnotic; Chloral Derivatives.
Dichloramine T Dichlorisone Dichlormid Dichloro(2-chlorovinyl)arsine Dichloroacetic Acid

Combination of
Phenazone Analgesic
Chloral hydrate Sedative
Clinical data
MedlinePlus a601064
Legal status Schedule IV (US)
Routes Oral
CAS number 480-30-8
ATC code N05CC04
PubChem CID 10188
DrugBank DB01495
ChemSpider 9776 YesY
UNII YYX637R279 YesY
KEGG D03785 YesY
 YesY (what is this?)  (verify)

Dichloralphenazone is a 1:2 mixture of antipyrine with chloral hydrate. In combination with paracetamol and isometheptene, it is the active ingredient of medications for migraine and vascular (tension) headaches, including Epidrin and Midrin. Performance impairments are common with this drug and caution is advised, for example when driving motor vehicles. Additional uses of dichloralphenazone include sedation for the treatment of short-term insomnia, although there are probably better drug choices for the treatment of insomnia.[1]