Deprescription of Gabapentinoids in Medical Inpatients

Gabapentinoids, which include gabapentin and pregabalin, are antiepileptic drugs that have been approved by the FDA and Health Canada for the treatment of postherpetic neuralgia, with pregabalin also approved for the treatment of diabetic neuropathy, fibromyalgia, and spinal cord injury-associated neuropathic pain. Despite a small number of approved indications, gabapentinoid prescription has increased substantially in recent years. The majority of new prescriptions are off-label for the treatment of multiple chronic pain conditions, such as osteoarthritis, chronic lower back pain, sciatica, and cancer-related pain.

A 2013 Cochrane review found reasonably good evidence for the use of both drugs in postherpetic neuralgia and painful diabetic neuropathy, as well as evidence supporting pregabalin use for the treatment of fibromyalgia and central neuropathic pain. However, there was either evidence against, or a lack of evidence for the efficacy of gabapentinoids in other chronic pain conditions. Furthermore, beneficial effects were associated with high risk of multiple adverse effects, including sedation, xerostomia, lower extremity edema, and traumatic falls in older adults.

In a recent study of inpatients at a tertiary-care hospital in Montréal, Canada between 2013 and 2017, 1 in 8 patients had a gabapentinoid prescription on admission, only 17% of which were for an FDA-approved indications. Gabapentinoid users had more comorbidities than non-users and were more likely to be co-prescribed opioids, which is concerning given previous evidence of increased opioid-related death with gabapentinoid co-prescriptions. Given their high prevalence of off-label use, their many adverse effects, and their frequent use among multimorbid patients who are vulnerable to these adverse effects, gabapentinoids are an ideal target for deprescription.

Patient education through the distribution of educational brochures is an effective method of promoting deprescription. A brochure specific to gabapentinoids is available on the Canadian Deprescribing Network website. This brochure contains a self-assessment of knowledge of the risks of gabapentinoids, provides information on the benefits and potential harms of use, presents safer treatment alternatives, and proposes a tapering regimen using an illustrated calendar, with instructions to contact a healthcare provider prior to discontinuation or tapering. This brochure aims to improve safe and successful deprescription by promoting patient motivation and self-capacity, and by encouraging patients to meet with their healthcare providers to create opportunities for deprescription.

In previous studies, a similar brochure was found effective in promoting benzodiazepine deprescription. In the Eliminating Medications through Patient Ownership of End Results (EMPOWER) trial, the distribution of educational brochures to 303 community-dwelling older adults who were chronically taking benzodiazepines resulted in a 27% discontinuation rate at 6 months, compared to a 5% discontinuation rate in the control group. The EMPOWER trial inspired a subsequent study in which the same brochure was distributed to medical inpatients at a tertiary-care hospital in Montreal, Canada. A total of 50 patients received the brochure while hospitalized, and 64% of those patients had discontinued benzodiazepines at 30 days-post discharge. This result was significantly higher than the hospital's historical deprescription rate of 21%. The higher deprescription rate associated with the intervention in this study compared to the EMPOWER trial highlights the importance of using hospital admissions as an opportunity for deprescription. Thus, the aim of this trial is to assess the efficacy of an educational brochure about gabapentinoids in improving gabapentinoid deprescription among elderly inpatients after discharge.

This study will follow a prospective controlled before and after study design involving five medical units across two centres: the McGill University Health Centre Glen Site (Royal Victoria Hospital) and the Montreal General Hospital. The sample size of the study is 160 participants, with 80 participants in the control group and 80 participants in the intervention group. The sample size was calculated to detect a 20% absolute increase in deprescription within the intervention group. Each study unit will act as its own control. The study will begin in the control period on all study units, until the pre-specified target of 80 control participants are enrolled. Once the enrolment of the 80 control participants has been completed, all study units will simultaneously transition to the intervention period. The intervention period will be completed once the pre-specified target number of 80 intervention participants is reached. Recruitment is expected to last approximately 10 months, with 16 patients enrolled per month. This rate of enrolment is based on previous study data regarding the prevalence of admitted gabapentinoid users and historical admission statistics from the study units, and assumes a study participation refusal rate of 15%.

During the control period, enrolled patients admitted to the medical ward will receive a pharmacy medication reconciliation as part of usual medical care. Although they will be informed that the goal of the trial is to evaluate medications and changes after discharge, participants will not be told that gabapentinoids are specifically being targeted. Additionally, medical staff will not receive specific information about the trial, or particular instructions related to deprescription.

During the intervention period, enrolled patients will receive an educational brochure about the risks of chronic gabapentinoid use and how to safely discontinue use. The educational brochure is written using a sixth-grade vocabulary and has been validated in both English and French for comprehension among individuals with and without mild cognitive impairment. Additionally, an educational session detailing purpose of the study and the risks of gabapentinoid prescription will be delivered to medical staff and residents on each study unit. The educational session will include a presentation by the chief of the medical service at the monthly teaching rounds, and an electronic message sent to all physicians on the medical service. The session will also include a brief overview of the brochure.

Follow-up questionnaires will be administered at 8 weeks after hospital discharge by telephone. The questionnaire will collect information regarding demographic changes, gabapentinoid deprescription, use of other pain medications, withdrawal symptoms, global functioning, pain control, and cognition.