Purified Dry Extract ofPaullinia cupana(Guaraná) (PC-18) for Chemotherapy-Related Fatigue in Patients with Solid Tumors: An Early Discontinuation Study

Paullinia cupana (guaraná) is an Amazonian plant that has been previously shown to be effective in treating chemotherapy-related fatigue (CRF) in patients with breast cancer. We aimed to evaluate the efficacy of a purified dry extract of P. cupana (PC-18) in patients with various solid tumors treated with chemotherapy.We included 40 patients with solid tumors who showed increases in their Brief Fatigue Inventory (BFI) questionnaire scores after 1 week of systemic chemotherapy. PC-18 was administered at 37.5 mg by mouth two times per day (PO bid), starting after 1 week of chemotherapy, for 3 weeks (induction phase). Patients who had an improvement in or stabilization of their BFI scores were randomized to receive either PC-18 at the same dose or placebo for the following 3 weeks (maintenance phase).After PC-18 treatment, the BFI fatigue scores improved or stabilized in 36 out of the 40 patients (mean BFI score difference = 2.503; 95% confidence interval: 1.716-3.375, p = .0002). Three weeks after randomization (16 patients on PC-18 and 17 on placebo), we observed no significant differences in the BFI, Functional Assessment of Chronic Illness Therapy, Hospital Anxiety and Depression Scale, and Pittsburgh Sleep Quality Index scores between patients randomized to PC-18 versus placebo.We conclude that the PC-18 extract may be effective for the treatment of CRF in patients with a variety of solid tumors. A conditioning effect, which was observed in patients who had a beneficial effect of PC-18 on CRF, may explain the better than expected fatigue scores of the placebo-treated patients.