Dichloralphenazone

Dichloralphenazone is a chemical compound that has been used in pharmaceutical preparations as a sedative and analgesic. It is described as a prodrug that, upon metabolism, releases chloral hydrate, a sedative-hypnotic, and phenazone, an analgesic and antipyretic component. Because of this dual action, formulations containing dichloralphenazone were intended to provide both calming effects and pain relief.

Historically, dichloralphenazone appeared in various combination products and was sometimes mixed with other analgesics or antipyretics. Its use reflects early efforts to combine sedative and analgesic effects in a single medication. Over time, concerns about the safety profiles of chloral hydrate and related compounds led to regulatory limits and, in many places, the withdrawal or restricted availability of products containing dichloralphenazone.

Safety and regulation have significantly limited the contemporary use of dichloralphenazone. Potential adverse effects associated with chloral hydrate include excessive sedation, respiratory depression, and, in some cases, dependency with prolonged use. Given these risks and the availability of safer analgesics and sedatives, dichloralphenazone-containing formulations have become rare in modern pharmacopoeias.

See also: chloral hydrate; phenazone; combination analgesics.