Efficacy and tolerability of the antispasmodic, pridinol, in patients with muscle-pain - results of primepain, a retrospective analysis of open-label real-world data provided by the German pain E-registry.

Objective: To evaluate efficacy and tolerability of the nonbenzodiazepine antispasmodic pridinol (PRI), as an add-on treatment in patients with muscle-related pain (MRP).

Methods: Exploratory retrospective analysis of depersonalized routine data provided by the German Pain e-Registry (GPeR) focusing on pain intensity, pain-related disabilities in daily life, wellbeing, and drug-related adverse events (DRAEs).Primary endpoint based on a global response composite of (a) a clinically relevant analgesic response (relative improvement ≥50% and/or absolute improvement ≥ the minimal clinical important difference) for pain intensity and disability in combination with (b) an improvement in wellbeing (all at end of treatment vs. baseline), and (c) lack of any DRAEs.

Results: Between 1 January 2018 and 31 December 2020, the GPeR collected information on 121,803 pain patients of whom 1133 (0.9%; 54.5% female, mean ± SD age: 53.9 ± 11.8 years) received add-on PRI for the treatment of (mostly acute) MRP originating predominantly in the (lower) back (43.2%), lower limb (26.4%), or should/neck (21.1%). Average daily dose was 7.8 ± 1.8 (median 9, range 1.5-13.5) mg, duration of treatment 12.0 ± 10.2 (median 7, range 3-63) days. In total, 666 patients (58.8%) reported a complete, 395 (34.9%) a partial, and 72 (6.4%) patients no response - either because of lack of efficacy ( = 2, 0.2%) or DRAEs ( = 70, 6.2%). In response to PRI, 41.7% of patients documented a reduction of at least one other pain medication and 30.8% even the complete cessation of any other pharmacological pain treatments.

Conclusion: Based on this real-world data of the German Pain e-Registry, add-on treatment with PRI in patients with acute MRP under real-world conditions in daily life was well tolerated and associated with an improvement of pain intensity, pain-related disabilities, and overall wellbeing.