Do analgesics improve functioning in patients with chronic low back pain? An explorative triple-blinded RCT

Treatment of patients with chronic low back pain (CLBP) aims to reduce disability, improve functional capacity, and participation. Time contingent prescription of analgesics is a treatment modality in CLBP. The impact of analgesics on functional capacity is unknown. Aim of the study was to explore the effect of analgesics on functioning measured by functional capacity evaluation, and self-reported disability in patients with CLBP.

Explorative Randomized Placebo-Controlled Clinical Trial was performed in an outpatient pain rehabilitation setting on patients waiting for rehabilitation. Included patients had low back pain lasting > 3 months, visual analogue scale worst pain a parts per thousand yen4.0 cm, and age > 18 years. Outcome measures before (T0) and after treatment (T1): functional capacity, pain intensity, Roland Morris Disability Questionnaire. T1: global perceived pain relief. Patient characteristics and psychological questionnaires were assessed. Fifty patients were included in this study and were randomly assigned to 2 weeks treatment or placebo. Treatment: acetaminophen/tramadol 325 mg/37.5 mg per capsule. Dose: maximum acetaminophen 1,950 mg and tramadol 225 mg per day; treatment and placebo titrated identically. Compliance and side-effects were monitored. Treatment effects between groups over time were compared.

One patient (treatment group) was lost to follow-up. Forty-nine patients remained in the study. Treatment effects in primary outcomes did not differ significantly between groups. A subgroup of 10 (42 %) patients (treatment group) reported global pain relief (responders) who reduced self-reported disability (p <0.05). Responders had significantly lower catastrophizing scores.

Overall treatment effects were small and non-significant. A subgroup, however, reported improved functioning as a result of treatment. Responders had lower catastrophizing scores.