Donepezil for cancer-related fatigue: A double-blind, randomized, placebo-controlled study

E. Bruera, B. El Osta, V. Valero, L. Driver, J. Palmer, B. Pei, L. Shen and V. Poulter

M. D. Anderson Cancer Center, Houston, TX

Background: Fatigue is the most frequent symptom in advanced cancer. No standard treatment is available. We previously found that open-label donepezil significantly improved fatigue by day 3 and 7 in patients (pts) on opioids for cancer pain (Fisch et al, ASCO 2003). The purpose of this study was to compare donepezil (D) with placebo (P) for fatigue in pts with advanced cancer.

Methods: In this randomized, double-blind, placebo-controlled trial, pts with fatigue score = 4 on a 0 to 10 scale (10 = worst fatigue) for > 1 week, hemoglobin = 10g/dl for = 4 weeks, and no major contraindication to D were randomized to receive D 5 mg or P orally every morning for 7 days. All pts were offered open-label D during week 2. Assessment included: research nurse daily phone call for fatigue and toxicity evaluation, Edmonton Symptom Assessment System (ESAS), Functional Assessment for Chronic Illness Therapy-Fatigue (FACIT-F), Sleeping Pattern Assessment, and overall effectiveness of the treatment. The FACIT-F fatigue subscale score on day 8 was considered the primary endpoint.

Results: 103 pts were evaluable for final analysis. Mean difference in scores for symptoms intensity between baseline and day 8 are shown in Table 1. FACIT-F fatigue subscale score at day 8 decreased a mean of 6 (10.6 SD) in the D arm (p < 0.001) and 7.2 (9.5 SD) in the P arm (p < 0.001). There was no significant difference in fatigue improvement between both arms according to the FACIT-F subscale (p = 0.57) and ESAS fatigue (p = 0.18) scores, and no significant difference in sleep quality score between D and P. On day 15 of the open-label phase, mean fatigue intensity remained significantly improved as compared to baseline on FACIT-F fatigue subscale (p < 0.001) and ESAS fatigue (p < 0.001) scores. No significant toxicities were observed.

Conclusions: Both donepezil and placebo resulted in significant fatigue improvement. Donepezil was not significantly superior to placebo after one week. Our pilot findings are probably due to placebo effect.