Pharmacological strategies and nutritional supplements for managing dysgeusia among chemotherapy patients: A systematic review

Background/objective: Among the side effects of chemotherapy, there is dysgeusia, which is an alteration or damage to the taste perception that negatively impacts the biopsychosocial sphere of the patient. Therefore, it is important to recognize and manage it appropriately. The objective of this study is to identify clinical pharmacological strategies to reduce dysgeusia in chemotherapy patients. Methods: A systematic literature review was conducted following the PRISMA guidelines between February and May 2023, utilizing PubMed, Embase, Cochrane Library, CINAHL, and the British Nursing Database. Methodological quality and bias risk assessment were performed using the JBI framework, while evidence certainty was evaluated using the Oxford OCEBM methodology. Results: Out of 1225 consulted records, 12 articles were included. The results underscore the efficacy of diverse pharmacological interventions in mitigating dysgeusia among chemotherapy patients. These include zinc supplementation with a daily dosage ranging between 50 and 220 mg (p ≤ 0.005), lactoferrin at 250 mg thrice daily (p < 0.001), delta-9-tetrahydrocannabinol at 2 mg per day (p < 0.05), and cannabidiol at 150 mg per day (p = 0.04). All studies analysed showed a low risk of bias. The zinc and Delta-9-Tetrahydrocannabinoid treatment proved particularly promising, compared to the other treatments considered, where sample sizes were smaller and the placebo effect was not always clear. Conclusion: Among the various pharmacological strategies identified, those that appear most promising concern the integration of zinc and Delta-9-Tetrahydrocannabinoid. Future studies should further explore the treatments identified in this review to expand the evidence base in this relatively underexplored field.