Prolotherapy is a therapeutic procedure used for chronic musculoskeletal and arthritic pain. It involves injecting an irritant solution to pain sites and causes patient discomfort, which can lead to treatment discontinuation. Remifentanil is an ultra short-acting µ-opiate receptor agonist that permits a rapid transition from intense analgesia to a minimal residual effect. Here, we evaluated the effect of remifentanil as a preparative medication for ambulatory prolotherapy.

Eighty patients taking prolotherapy were assigned into three groups for pre-therapeutic injections: remifentanil 0.1 µg/kg/min alone (Group R), remifentanil 0.05 µg/kg/min with midazolam 2 mg (Group M), and normal saline (Group C). Pain and sedation scores, blood pressure, pulse oxygen saturation, heart rate, satisfaction score, and time to discharge were measured.

Pain scores in groups M and R were lower than group C during and after prolotherapy. The sedation score of group M was higher than groups R and C. Nine patients in group R experienced dizziness during prolotherapy. In group M, 8 patients experienced dizziness and 2 patients experienced nausea. There was no difference in time to discharge among all groups. Satisfaction scores in group M (7.3 ± 0.8) and group R (7.0 ± 0.8) were higher than that of group C (5.3 ± 0.6).

Remifentanil and remifentanil/midazolam effectively reduce the pain produced by prolotherapy.