EMA confirms positive benefit-risk for antidepressant Valdoxan/Thymanax (agomelatine)
Measures introduced to improve monitoring of liver function during treatment
The European Medicines Agency has completed a review of the anti-depressant medicine Valdoxan/Thymanax and concluded that its benefits continue to outweigh the risks. However, the Agency has recommended that further measures should be put in place to minimise the risk of liver toxicity. Valdoxan and Thymanax are two identical medicines used to treat major depression in adults.
A patient booklet will be distributed to all patients taking Valdoxan/Thymanax so that they are aware of the risk to the liver and the signs of liver problems to look out for. This booklet also includes information on the importance of monitoring liver function.
Warnings in the product information will also be strengthened to emphasise that liver function tests should be performed in patients both before starting the medicine and regularly during treatment. If tests suggest liver injury (i.e. increase of certain liver enzymes called transaminases in the blood to more than 3 times the upper limit of normal) doctors should not start their patients on Valdoxan/Thymanax or stop treatment of those who are already taking the medicine.
Valdoxan/Thymanax was first approved in 2009 on the basis of studies showing that the medicine has comparable effects to other antidepressants. Since the medicine has a different mode of action and a different safety profile to existing antidepressants, it was concluded that Valdoxan could be a valuable treatment for some patients as long as their liver function is tested regularly. However, side effects on the liver have continued to be reported and an observational study has shown a considerable level of non-compliance with the recommended liver monitoring programme. The Agency has therefore concluded that there is a need to reiterate the importance of liver monitoring, which is the cornerstone for the safe use of the product.
The new recommendations follow the most recent benefit-risk assessment of Valdoxan/Thymanax from the Agency’s Pharmacovigilance Risk Assessment Committee (PRAC). As part of its recommendations, the PRAC had even considered that the use of Valdoxan/Thymanax should be contraindicated in patients aged 75 years or above since these patients might be at an increased risk of severe side effects on the liver and beneficial effects have not been documented in this population. The current product information for Valdoxan/Thymanax includes a warning that the medicine should not be used in patients aged 75 years or over. The CHMP considered that upgrading this warning to a contraindication in this population was not justified by the available data.
The CHMP opinion will now be sent to the European Commission, which will issue a legally binding decision.
Posted on the EMA website on 26 September 2014