Abstracts

Rationale: CLB and clonazepam (CLN) have been used for many years in Europe for a variety of epilepsy disorders and anxiety. Diazepam (DZP) is widely used in anxiety, but is also recommended by clinical guidelines for status epilepticus (SE). 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). We analyzed data from the CPRD to compare evolution of clobazam (CLB), clonazepam (CLN), and diazepam (DZP) treatment for epilepsy vs. anxiety based on UK clinical practice. Methods: Patients with ≥1 incident prescription of CLB, CLN, or DZP within the study period (1995-2011) were included. Date of a patient's first prescription for any of the 3 drugs was termed index date. Patients must have also had ≥182 days in the database before index date without any prescriptions of CLB, CLN, or DZP to ensure that no previous CLB, CLN, or DZP had been prescribed. Patients were classified in epilepsy if they have had a diagnosis of epilepsy any time prior to or ≤90 days after index date, in anxiety if they had a diagnosis 90 days around index date for anxiety, and in other for other diagnoses (mostly depression, insomnia). Results: A total of 574,332 patients met inclusion criteria. Of these, 3,882 received CLB, 17,217 received CLN, and 553,233 received DZP. Cumulative usage over the 16-year period for epilepsy vs. anxiety for all 3 drugs is provided below (table). Evolution of the numbers of incident users by product and diagnoses between 1995 and 2011 indicated very different patterns. For CLB, use in anxiety was low at the beginning (1995) and further decreased over time, while use in epilepsy has increased steadily and dramatically. For CLN, use in anxiety was similar to use in epilepsy, both of which have increased over time. Overall, DZP is the most commonly used drug of the 3, with 76.4% of its use in insomnia, MDD, or related diseases. Its use in epilepsy was low at the beginning (1995), slightly increased to a peak in 2005, and then slightly decreased thereafter. Conclusions: This is the first study to evaluate use of benzodiazepines in epilepsy and anxiety over 15 years. CLB use has been predominantly in epilepsy (76.1%), and has steadily increased over time. CLN use has been mainly in other diagnoses, such as insomnia, MDD, or related diseases (83.7%). CLN use in epilepsy (8.7%) has increased over time, but to a degree similar to its use for anxiety. DZP's percentage use in epilepsy has been very low and has decreased over time, as evidenced by its use as a rescue medication for SE.