Abstracts

Rationale: In October 2011, clobazam (CLB), a novel 1,5-benzodiazepine, was approved by the US Food and Drug Administration for the treatment of seizures associated with Lennox-Gastaut Syndrome in patients 2 years of age and older. In addition, CLB and the 1,4-benzodiazepines, such as clonazepam (CLN), have been used for many years in Europe for the treatment of various epilepsy disorders, as well as for anxiety. The Clinical Practice Research Datalink (CPRD) database, a large, longitudinal primary care database, consists of electronic medical records from general practitioners located throughout the United Kingdom (UK). It covers 4.8 million active patients from approximately 590 primary care practices. It has been used for a variety of scientific analyses, including drug safety, clinical epidemiology, and health economics and outcomes research. We analyzed data from the CPRD to compare the usage of CLB and CLN in routine clinical practice in the UK.Methods: All patients who had at least one incident prescription of CLB or CLN within the study period defined as Jan. 1, 2001, to Dec. 31, 2010, with a diagnosis of epilepsy or anxiety disorders were included. The date of a patient s first prescription of either drug was termed the index date. In addition, patients must have had 182 days in the database before index date without any prescriptions of CLB or CLN to ensure that no previous CLB or CLN had been prescribed. Patients must also have had a diagnosis of epilepsy or anxiety any time prior to or up to 90 days after their index dates. Patients were followed until the end of their CLB or CLN therapy, or until Feb. 28, 2013.Results: A total of 8,249 patients met the inclusion criteria above. Of these, 2,870 received CLB and 5,379 received CLN. Usage for epilepsy vs. anxiety for both drugs is provided below (table). Patients treated for epilepsy receiving CLB were younger than those receiving CLN (mean SD: 34.9 18.6 years vs. 43.6 21.0 years, p<0.0001). Further, 92.8% of patients with epilepsy receiving CLB were also receiving concomitant AED therapy (vs. 76.0% for CLN). The percentages of men vs. women receiving either treatment were similar.Conclusions: Based on these data from CPRD, clobazam is primarily an adjunctive therapy for epilepsy in the United Kingdom, while clonazepam is used for anxiety. This is further supported by the younger patients, on average, being treated with clobazam, as well as the greater percentage of clobazam-treated patients receiving concomitant AEDs.