Assessment of safety of methylphenidate in ADHD treatment

29 October 2010

The Danish Medicines Agency has reviewed the data on consumption and side effects of methylphenidate-containing medicine, which is authorised for the treatment of ADHD and narcolepsy.

You can download the full report in Danish in the factbox to the right: ‘Rapport om vurdering af sikkerheden ved brug af methylphenidat til behandling af ADHD’.

Main conclusions of the report

Medicines containing methylphenidate are authorised for treatment of ADHD in children and adolescents (aged 6-18 years), and for the treatment of the rare disorder narcolepsy. In 2009, more than 11,000 adults in Denmark were prescribed methylphenidate, which shows that the medicine is widely used off label.

Based on a thorough review of the Danish Medicines Agency’s data on consumption and side effects, we have found no causes to change the current safety information with regard to the use of methylphenidate for the treatment of children and adolescents with ADHD. We will maintain focus on the safety of methylphenidate, including side effects associated with long-term use.

The experience with methylphenidate for the treatment of adults with ADHD is positive. However, we find it necessary to highlight that when considerable off-label use occur, there is no adequate documentation available for the medicine's safety in relation to the patient group concerned.

Our focus is therefore that the risk profile of methylphenidate may be different for adults with ADHD. We have identified four risk areas for adults that we believe are important to pay attention to:

  • risk of developing cardiovascular disease,
  • risk associated with treatment during pregnancy,
  • risk of abuse, and
  • serious mental disorders.

We expect the risk profile for adults treated with methylphenidate to be at least identical with the risk profile for children, but it is more difficult to minimise the risks for adults because there are no instructions in the medicine’s summary of product characteristics and no detailed guide for treatment of adults – which there is for children.

Why do we focus on methylphenidate in ADHD treatment?

The Danish Medicines Agency monitors all medicine authorised in Denmark. We monitor new medicines on the market more closely, but sometimes it also becomes necessary to put focus on medicine that has been on the market for many years, for example if changes occur in the way a medicine is used.

Changes have occurred for methylphenidate, which was originally authorised under the name Ritalin®. Data from the Danish Medicines Agency’s Register of Medicinal Product Statistics indicate that the consumption of methylphenidate has increased considerably over the last ten years. Upon consultation with the Council for Adverse Drug Reactions, we therefore decided in early 2010 to thoroughly review the safety, the side effects and the consumption pattern of methylphenidate in ADHD treatment.

For further information
, please contact Chief Medical Officer Doris I. Stenver, Consumer Safety Division, on +45 4488 9247 or mobile +45 2246 0979.

Danish Medicines Agency, 26 October 2010