Evaluation of the Effectiveness of the Risk Minimization Measures of Sodium Oxybate in the European Union.

BACKGROUND

Sodium oxybate (Xyrem), approved by the European Medicines Agency (EMA) for narcolepsy with cataplexy, is only available through risk mitigation programs due to potential adverse effects including respiratory and central nervous system depression, neuropsychiatric events, and misuse.

OBJECTIVE

We report findings from a survey evaluating effectiveness of the European Union Xyrem Risk Management Plan (RMP).

PATIENTS AND METHODS

A cross-sectional, online, multiple-choice survey was distributed to randomly selected healthcare professionals (HCPs) from six European countries (April 2016-May 2018). Eligibility criteria: current/potential Xyrem prescriber and/or sleep disorder specialist; contact information available; on the Xyrem RMP educational materials mailing list.

PRIMARY OUTCOME

proportion of respondents answering each question correctly (< 50% responses correct = unsatisfactory comprehension, 50% to < 70% = satisfactory, ≥ 70% = excellent), with precision assessed using 95% confidence intervals (CIs).

RESULTS

Of the 709 HCPs contacted, 601 did not agree to take part, 108 were screened with 35/108 eligible for inclusion; 31 HCPs completed the survey. Of the 31 respondents, 29 (93.5%; 95% CI 84.4-100.0) reported receiving Xyrem safety information, commonly from a sales representative, EMA Summary of Product Characteristics (SmPC), or educational meeting; only 9/31 (31.0%; 14.3-50.0) recalled receiving mailed educational materials. The number of HCPs answering dosing-related questions correctly ranged from 24/31 to 31/31. All Xyrem contraindications were correctly identified by 26/31 (83.9%; 70.0-96.7) respondents. All respondents 'always' or 'sometimes' completed SmPC recommended activities upon treatment initiation. The majority indicated signs of abuses/misuse/diversion (23/31; 74.2%; 58.6-88.0) and criminal use (23/31; 74.2%; 59.4-89.3) should be monitored at follow-up.

CONCLUSIONS

These data demonstrate the importance of providing a range of educational materials. However, the low sample size limits interpretation; increased HCP engagement would improve understanding of how best to develop educational materials.

EUROPEAN POST-AUTHORIZATION STUDY (PAS) REGISTER NUMBER: EUPAS15024.