The goal of this parallel-group, single-blinded, randomized study is to conduct Medication Review (MR) Type III in chronic non-cancer pain patients to optimize drug therapy and measure it's influence on Pain Intensity and Quality of Life in the primary care setting. The study took place in Porto, Portugal with the collaboration of two Primary Care Units (USF Arca D'Água and USF Campanhã - Polo S. Roque da Lameira) under ACeS Porto Oriental, from where patients were recruited. The main question it aims to answer is:

• Does the implementation of pharmacist-led medication review benefit patients with chronic pain in the primary care setting?
• Researchers will compare with "Usual Care" (UC) patients which receives general advice on how to manage their pain and/or recommendations to take "over the counter" drugs, similar to community pharmacy visits, to see if there is a clinically significant difference in pain intensity and quality of life between the two groups of patients.
• Participants will be asked to attend face-to-face interviews once a month for 4 months with an expert in medication review, that evaluates their current medication and suggests an individualized care plan. These plans include measures aimed at physicians (e.g., medication adding; dose reduction) and participants (e.g., non-pharmacological measures; adherence to medication).

Inclusion Criteria:

• Non-cancer chronic pain (>3 months, any cause)
• Follow-up at one of the selected Primary Care Units
• Average weekly pain score ≥4 at the screening phase
• Ability to attend monthly in-person or video interviews

Exclusion Criteria:

• Pregnancy
• Breastfeeding
• Dementia
• Other mental illness impairing self-reporting

Individual participant data that underlie the results reported in the study (including de-identified individual-level data) will be made available upon reasonable request. The data will include all variables used in the analysis relevant to the primary and secondary outcomes, excluding any information that could compromise participant privacy or confidentiality.

The IPD will be available beginning 6 months after publication of the primary results and will remain available for up to 4 years following publication.

Researchers who provide a methodologically sound proposal and have appropriate institutional approval may request access. Proposals should be submitted to the study principal investigator via email. A data use agreement will be required prior to the release of data.

This trial is blinded to subjects. Each subject will be informed they will be allocated to one of the two arms without knowing which one. Subjects will know they will receive pharmaceutical care, despite not knowing what type of pharmaceutical care they will receive.