Pilot Study To Determine the Optimal Dose of Methylphenidate for an n-of-1 Trial for Fatigue in Patients with Cancer

Abstract

Purpose: In advanced cancer, the prevalence of fatigue is high and can be related to treatment or disease. Methylphenidate hydrochloride (MPH) is a central nervous system stimulant that has been used to palliate fatigue. There is no standard dose for MPH when used for this indication; recommended doses range from 5-20+mg/d. Method: To identify a dose to test formally in a subsequent n-of-1 trial of fatigue, we recruited patients with advanced cancer and a fatigue score of 4 or more on a 10-point scale. Following a 3-day baseline assessment, each patient titrated MPH at doses ranging from 5mg/d to 15mg twice daily at 3-day intervals. In a daily diary, patients recorded measures of fatigue, depression, toxicity, and symptom control. Results: Ten patients provided consent, 9 completed 8 days and 5 received maximum dose at day 15. Three patients were unwilling to increase the dose to maximum levels as they were satisfied with the response at a lower dose. Across all patients, there was a pattern of rapidly improving fatigue and depression scores to day 9 (5mg twice daily), with minimal improvement thereafter. Conclusion: The results indicate a dose of 5mg twice daily for the definitive study. There was little correlation between performance status and maximum tolerated dose. No patient withdrew because of toxicity.