RESUMEN
BACKGROUND: Pharmacists can play an important role in pain management. OBJECTIVE(S): This review aims to summarize the effects of any type of pharmacist intervention, whether led by a pharmacist or in a supportive role, on pain intensity over time in individuals with pain of any etiology. METHODS: Three electronic databases (MEDLINE, Embase, and Cochrane Central Register of Controlled Trials) were searched from inception to the end of May 2021 to identify randomized controlled trials (RCTs) that reported the effect of pharmacist interventions on pain intensity. Two reviewers independently extracted data and evaluated study quality. The analyses used a random-effects models and the Grading of Recommendations, Assessment, Development and Evaluation to rate the certainty of the evidence. The primary outcome was reduction in pain intensity and presented as standardized mean differences (SMD). RESULTS: Twelve RCTs including 1710 participants were included. Pooled estimate of 12 studies demonstrated a statistically significant reduction in pain intensity compared with control (SMD -0.22 [95% CI -0.31 to -0.12], I2 = 0%, low certainty). The intervention was more effective when a pharmacist delivered a combination of services comprising educational interventions, medication review, and pharmaceutical care services (SMD -0.24 [95% CI -0.35 to -0.13], I2 = 0%, moderate certainty). For educational interventions alone, no statistically significant difference was observed (SMD -0.15 [95% CI -0.45 to 0.15], I2 = 47.6%, low certainty). Pharmacist intervention was also effective in reducing pain intensity for patients with cancer-related pain (SMD -0.76 [95% CI -1.17 to -0.36], I2 = 0%, moderate certainty). CONCLUSION: There is some promising evidence to suggest that multicomponent pharmacist interventions including medication review or any other pharmaceutical care services, rather than merely educational interventions, are beneficial in reducing pain intensity, particularly in patients with chronic pain. High-quality RCTs are required to confirm the clinical significance of this findings before advocating for its widespread implication in clinical practice.