The European Medicines Agency (EMA) recommends withdrawing the registration certificates for medicinal products containing levamisole Leukoencephalopathy has been confirmed as a serious adverse reaction with the use of levamisole

In accordance with paragraph 8 of Section IV of the Procedure for Expert Evaluation, the applicant must amend the instructions for medical use of the medicinal product upon receipt of new data, including bringing the instructions for medical use into line with the approved instructions for medical use of the original (reference) medicinal product, and ensure that the information on the medicinal product corresponds to current scientific knowledge.

On 26 March 2026, the Coordination Group for Mutual Recognition and Decentralized Procedures – Human (CMDh)¹ endorsed the recommendation of the Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA) to withdraw medicinal products containing levamisole from the market of the European Union (EU). This decision was made following a Europe-wide review, which concluded that the benefit of using these medicinal products no longer outweighs their risks for the treatment of helminth infestations in adults and children.

The review confirmed that leukoencephalopathy is a rare but serious adverse reaction with the use of levamisole. Leukoencephalopathy damages the white matter of the brain, which consists of nerve fibers covered with myelin – a protective layer that ensures efficient transmission of nerve impulses between areas. This condition can lead to severe consequences and be life-threatening, especially in the absence of appropriate treatment, and its diagnosis is complex.

The data reviewed by the PRAC showed that leukoencephalopathy can occur after a single administration of levamisole, and symptoms may appear within several months after treatment. The review did not identify any measures to reduce the risk or any group of patients at increased or decreased risk. In addition, other medicinal products for the treatment of nematodoses are authorized in the EU. Taking into account that medicinal products containing levamisole are used to treat mild nematodoses, and that levamisole-induced leukoencephalopathy is a serious condition with unpredictable onset, the PRAC concluded that the benefits of medicinal products containing levamisole no longer outweigh the risks, and recommended withdrawing the registration certificates of these medicinal products in the EU.

The PRAC recommendation is based on an assessment of new data collected as a result of ongoing safety monitoring of medicinal products authorized in the EU. These data included reports of serious cases of leukoencephalopathy and demyelination of the central nervous system (loss of myelin in the brain and spinal cord) following the use of levamisole, as well as a review of the published scientific literature. The PRAC also considered the conclusions of a group of independent experts in infectious diseases and neurologists, as well as data provided by the World Health Organization.

The EMA continuously monitors the safety of medicinal products authorized in the EU. When new data indicate that the risks of a medicinal product may outweigh its benefits, the EMA takes action to protect public health. The recommendation on the withdrawal of medicinal products containing levamisole reflects the EMA’s commitment to ensure that medicinal products authorized in the EU meet high standards of safety, efficacy and quality.

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¹ The CMDh is a body representing the EU Member States as well as Iceland, Liechtenstein, and Norway. It is responsible for ensuring harmonized safety standards for medicinal products authorized under national procedures in all EU countries.

Information for patients

• EMA has recommended withdrawing from the EU market medicinal products containing levamisole. In some EU countries, these medicinal products are registered for the treatment of nematode infections.
• The review conducted by PRAC confirmed that medicinal products containing levamisole can cause leukoencephalopathy, a serious adverse reaction that damages areas of the brain.
• Other medicinal products for the treatment of nematode infections are registered in the EU.
• People who have been treated with a medicinal product containing levamisole should seek medical attention immediately if they develop muscle weakness, speech difficulties, confusion, or loss of motor control.
• These symptoms may occur after a single use of levamisole (levamisole) and may develop within several months after treatment with a medicinal product containing levamisole (levamisole).
• If you have any questions about your or your child’s past or current treatment with a medicinal product containing levamisole, please consult your doctor.

Information for healthcare professionals

• EMA has recommended withdrawing from the EU market medicinal products containing levamisole. In some EU countries, these medicinal products are registered as anthelmintics.
• The review conducted by PRAC confirmed that levamisole can cause leukoencephalopathy – a serious adverse reaction with an unpredictable onset.
• Symptoms of leukoencephalopathy may occur after a single use of levamisole and may develop within several months after treatment.
• In patients with levamisole-associated leukoencephalopathy, neurological symptoms vary depending on the location of the lesions and may include muscle weakness, speech disorders, cognitive impairment, ataxia, and paresis.
• Other anthelmintic products are registered in the EU.
• The EMA recommendation is based on a Europe-wide review of spontaneous reports of leukoencephalopathy and demyelination of the central nervous system after the use of levamisole, both for its authorized indications and in the context of use of the medicinal product other than as intended (off-label use), misuse, or accidental exposure, a review of the scientific literature, and input from a group of independent experts in infectious diseases and neurology.
• An information letter addressed to healthcare professionals (DHPC) will be sent to the relevant healthcare professionals and published on a dedicated page of the EMA website, at the link: https://www.ema.europa.eu/en/human-regulatory-overview/post-authorisation/pharmacovigilance-post-authorisation/direct-healthcare-professional-communications-dhpc.

More about the medicinal product

Levamisole is an anthelmintic agent used in adults and children for the treatment of infections caused by Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, Strongyloides stercoralis and Trichostrongylus colubriformis.

Levamisole (levamisole) acts mainly by stimulating nicotinic acetylcholine receptors, which are proteins located on the surface of the nerve cells of the helminth. This leads to rapid paralysis of the helminth's muscles, which prevents its movement and allows it to be expelled from the intestine of the infected person.

Medicinal products containing levamisole are available as tablets for oral use, usually as a single dose. They are registered in Hungary, Lithuania, Latvia, and Romania under the trade names Decaris and Levamisol Arena.

More about the procedure

The review of medicinal products containing levamisole was initiated at the request of the Romanian Medicines Agency (NAMMDR) pursuant to Article 31 of Directive 2001/83/EC.

The review was conducted by the PRAC, the committee responsible for assessing the safety of medicinal products, which issued a recommendation. Since all medicinal products containing levamisole were registered under national procedures, the PRAC recommendation was sent to the CMDh, which adopted its position on 26 March 2026. The CMDh is a body representing the EU Member States as well as Iceland, Liechtenstein and Norway. It is responsible for ensuring harmonized safety standards for medicinal products registered under national procedures in all EU countries. Since the CMDh adopted its position by consensus, the PRAC recommendation will be implemented directly by the Member States where the medicinal products are registered under national procedures, in accordance with an agreed timetable.

TO ANALYZE THE PUBLISHED INFORMATION AND SUBMIT THE RELEVANT APPLICATION FOR AMENDMENTS TO THE REGISTRATION MATERIALS, THE APPLICANT MUST USE THE ORIGINAL TEXT AVAILABLE AT THE FOLLOWING LINKS: