OBJECTIVE: To compare patient characteristics and treatment patterns among clobazam (CLB) and clonazepam (CZP)-treated patients with epilepsy in a longitudinal primary care database. METHODS: In this pharmacoepidemiological study, real-life usage data from the Clinical Practice Research Database (CPRD) were evaluated. The CPRD collects data from approximately 690 primary care practices throughout the UK. Data included were from patients with >/=1 incident CLB or CZP prescription from 1995 to 2011 and were present in the database for >/=182 days prior to the index date (date patient was first prescribed CLB or CZP within the study period). RESULTS: Of 21,099 patients who met inclusion criteria, 18.4% were receiving CLB and 81.6% were receiving CZP. More patients used CLB for epilepsy than CZP (76.1% vs 8.7%). CLB-treated adults (=18years) were younger than those treated with CZP (41.0 vs 48.2 years; p<0.001), while CLB-treated children (=18 years) were older than those treated with CZP (8.8 vs 7.3 years, p<0.001). The median CLB dosage did not change from baseline to last follow-up, while median CZP dosage increased 25% in adults and 50% in children. Median treatment duration, as well as retention rate up to 10 years, was similar between CLB and CZP in each age group. CONCLUSIONS: Among adult and pediatric patients in the UK, CLB is more often prescribed for epilepsy than CZP. The median CLB dosage used by both adults and children remained stable over the 16-year study period, while the median CZP dosage increased in both adults and children.