Review will assess risk of leukoencephalopathy, a condition affecting the brain

EMA’s safety committee (PRAC) has started a review of medicines containing levamisole, authorised in four countries of the European Union (EU) to treat infections caused by parasitic worms in adults and children.

The review follows concerns about a risk of leukoencephalopathy, a potentially serious condition that damages the white matter of the brain. White matter is made of nerve fibres covered by a protective layer called myelin, which allows efficient communication between different parts of the brain. Leukoencephalopathy can be life-threatening and debilitating, especially when left undiagnosed or untreated. It may lead to a range of neurological symptoms, including but not limited to confusion, weakness or impaired muscle function, difficulties with movement coordination, and impaired or lost speech or vision.

Leukoencephalopathy has already been identified as a potential risk with levamisole, and…