To ask Her Majesty's Government when the drug clonazepam was first licensed for treatment in the United Kingdom; and what assessment they have made of whether the drug has had adverse effects on patients.

Clonazepam belongs to the class of medicines known as benzodiazepines. When benzodiazepines were introduced into the market in the United Kingdom there was not a formal system of medicines regulation. In 1971 after implementation of the Medicines Act 1968, all medicines were given a licence of right, and these licences were reviewed over time by the Committee on Review of Medicines (CRM) and granted a reviewed licence if they met the requirements of safety, efficacy and quality.

Clonazepam, which is used for the treatment of epilepsy in infants, children and adults, was granted a product licence of right on 13 June 1974.

As with all medicines authorised in the UK, the safety of clonazepam has been kept under close and continuous scrutiny by the Medicines and Healthcare Products Regulatory Agency (MHRA) using a wide variety of data sources. These include spontaneous adverse drug data from the UK and worldwide, clinical trials and epidemiological studies, worldwide published medical literature, data from the manufacturer and information from worldwide regulatory authorities.

The MHRA captures data on potential side effects associated with medicines through its Yellow Card scheme. Doctors, dentists, coroners, pharmacists, nurses and patients can report suspected side effects to the MHRA through the Yellow Card scheme. A total of 174 spontaneous case reports have been received detailing 382 reactions suspected to be associated with the use of clonazepam in the UK. The most commonly reported suspected adverse reactions include aggression (14 reports), somnolence (12), mania (9), ataxia (8) and epilepsy (8). All of these adverse reactions, or the symptoms commonly used to describe these conditions, are included in the product information for clonazepam.

Information to aid the safe use of clonazepam is provided in the product information which consists of the summary of product characteristics for healthcare professionals and the patient information leaflet. These are available on the internet at emc.medicines.org.uk/searchresults.aspx?term=clonazepam&searchtype=QuickSearch.

Additional prescribing advice is provided in the British National Formulary, which is sent to all doctors within the National Health Service.