Chlormezanone has been used in the treatment of anxiety disorders and is also commonly used in combination with analgesics for relief of painful muscle spasm.

The NPA received reports that the use of chlormezanone-containing products has been associated with reports of life-threatening toxic epidermal necrolysis and borderline bullous major forms. As a result, chlormezanone-containing products have been withdrawn in a number of countries including the European Union and Japan.

In Singapore, the Ministry has also decided to de-register all products containing chlormezanone. The product licences for all chlormezanone-containing products will be revoked on 31 March 2000. Product licences, which expire before this date will not be renewed. New product applications for chlormezanone-containing products would also not be approved.