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 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]
^Hindmarch I, Parrott AC (1980). "The effects of combined sedative and anxiolytic preparations on subjective aspects of sleep and objective measures of arousal and performance the morning following nocturnal medication. I: Acute doses". Arzneimittel-Forschung. 30 (6): 1025–8. PMID6106498.