Adherence to Adjuvant Neuropathic Pain Medications in a Palliative Care Clinic

Currently, few studies exist on patient adherence to adjuvant neuropathic pain (NP) medications in the palliative care setting.

We assessed patient adherence rates to NP medications in a palliative care clinic and compared patient self-reported adherence to pharmacy refill records.

This was an observational single-site cross-sectional study of patients with NP receiving at least one NP medication for at least three months. Participants who met the inclusion criteria and agreed to participate completed the eight-item Morisky Medication Adherence Scale (MMAS-8) and a seven-day-recall (7DR) adherence measure. Patients gave permission to contact their pharmacy after the visit to collect refill records for the six months prior to the clinic visit. This information was used to calculate the medication possession ratio (MPR).

We analyzed 32 patients; most (81%) had NP related to a cancer diagnosis. Approximately 87.5% had low or medium adherence using the MMAS-8. The mean self-reported adherence based on 7DR was 94%. The mean MPR was 63%. A majority of patients (88%) had high self-reported adherence (>80%); however only 44% of patients had an MPR >80%.

Results indicated that the MPR might be a more accurate measure of adherence than patient self-report. More research is needed to assess and improve adherence with NP medications in the outpatient palliative care setting.