Background SF-36 is a questionnaire used in clinical practice to measure subjective patient health. It includes 8 scales: physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, mental health.

Purpose To describe Pain Unit patients' pharmacotherapy and evaluate its influence on SF-36 responses.

Materials and methods Retrospective study that included patients attended in the pain management unit between October 2009 and May 2010. Patients completed at least two SF-36 questionnaires. The electronic history was used to collect demographic (sex, age) and treatment information (diagnosis, pain pharmacotherapy before and after the first clinical visit). Scores obtained in the two questionnaires were compared and The authors calculated the number of patients with improved SF-36 scores.

Results 173 patients were attended during the study period, but only 47 were included. Sex distribution: 61.7% female and 38.3% male. Mean age was 56.3 (22-82) years. Chronic lower back pain and postsurgical neuralgia were the main diagnoses. On the first clinical visit NSAIDs (36.2%) and analgesics (34%) were the most prescribed groups followed by weak opioids, antidepressants, anticonvulsants and strong opioids. On the second visit anticonvulsants, antidepressants and strong opioids were the most frequently-prescribed groups. There were no changes between the two questionnaires on role-physical and role-emotional scales and very little difference on bodily pain measures. More than half of patients reported improved results on physical functioning, general health, vitality and mental health scales. The combination of anticonvulsants and antidepressants was associated with an improvement on these scales. Better results were observed if opioids were added to treatment.

Conclusions Pharmacotherapy changes after the clinical visits improved physical functioning, general health, vitality and mental health. Antidepressants and anticonvulsants alone or in combination with opioids were the main groups involved. It is interesting to know the drugs used in a Pain Unit, their impact on SF-36, and to evaluate whether the goal of pain relief was really reached and whether patients received optimal pharmacotherapy.