A retrospective database study of the prescribing of zonisamide in UK general practice: a drug utilisation study as part of post marketing safety surveillance.

Date of ISAC Approval: 
09/06/2016
Lay Summary: 
When drugs are approved for use, companies may be requested by the regulator to check that doctors follow prescribing instructions in cases where the drug could cause serious side effects, particularly in children. This study has been designed to check if the drug zonisamide, used in children with epilepsy, is being given to children of appropriate weight and prescribed alongside the additional epilepsy drugs that are recommended with its use. This drug should not be used with drugs called anti-cholinergics or carbonic anhydrase inhibitors and so prescriptions for these will be quantified. This study will be conducted in the Clinical Practice Research Datalink (CPRD) from October 1st 2013 until March 31st 2016 (or last available data in 2016) and results reported to the European Medicines Agency as part of post marketing safety surveillance.
Technical Summary: 
As part of European risk mitigation strategies for zonisamide (Zonegran), Eisai has committed to a drug utilization study in the paediatric population >/=6 years and </=17 years of age in the UK. The European Medicines Agency (EMA) has requested a database study in order to evaluate whether recommendations in the zonisamide "Summary of Product Characteristics (SmPC)" regarding dosing and risk mitigation strategies are being adhered to by general practitioners, who undertake routine prescribing for paediatric epileptic patients. This study, conducted in the Clinical Practice Research Datalink (CPRD) from October 1st 2013 until March 31st 2016 (or last available data in 2016) will report the age range and clinical background of paediatric patients prescribed the drug, including weight, height and BMI. Diagnosed co-morbidities pre and post exposure to zonisamide will be reported, as well as laboratory data for serum bicarbonate levels which should be monitored. Additionally, the concomitant prescribing of other carbonic anhydrase inhibitors with the same mechanism of action as zonisamide and prescribing of anticholinergic drugs which are both contra-indicated will be evaluated. Results will be submitted as part of the Clinical Safety Report (CSR) and fulfilment of the post approval measure as reported in the Sections III.2 and III.4 of the Risk Management Plan (RMP).
Health Outcomes to be Measured: 
Drug utilisation of zonisamide in UK general practice
Collaborators: 

Louise Watson - Chief Investigator - Explore-Epi
Louise Watson - Corresponding Applicant - Explore-Epi
Dr Luigi Giorgi - Collaborator - Eisai Pharmaceuticals
Ruth Farquhar - Collaborator - Exploristics