Real World Effectiveness of Orphenadrine Citrate 35 mg + Paracetamol 450 mg (Norgesic®) on Low Back Pain of Filipino Patients
Authors:   University of the East Ramon Magsaysay Memorial Medical Center, Inc, Nailes Jennifer M. , M. Javier Ramon Jason , L. Adversario Maria Peñafrancia , M. Rubi Kristine Pearl ,   University of the East Ramon Magsaysay Memorial Medical Center, Inc, P. Salvino Roberto ,   iNova Pharmaceuticals, D. Lentejas Ferdinand ,   iNova Pharmaceuticals
Published: November 2024

Introduction: Low back pain (LBP) is a prevalent musculoskeletal condition, believed to impact as many as 84% of adults during their lifetime. It ranks among the primary reasons for limitations in activity, absenteeism from work, and reduced productivity, resulting in significant costs to health, social, and economic systems. Furthermore, the Philippines has been identified as one of the countries where 56% of its population suffers from weekly body aches. Thus, the study determined the effectiveness of orphenadrine citrate 35 mg + paracetamol 450 mg (Norgesic®) in relieving acute, non-specific moderate to severe musculoskeletal LBP among adult Filipino patients in a real-world setting. Methods: A prospective, multi-center, uncontrolled, open label, longitudinal study was done. Study participants were recruited via purposive sampling by their attending physicians, and they were given Norgesic® according to local prescribing guidelines and standard clinical practices. Pain levels were measured using the visual analogue scale (VAS), while self-reported physical disability was assessed using the Roland-Morris Disability Questionnaire (RMDQ). Patients were monitored until their low back pain completely resolved or for a maximum of ten (10) days. This real-world evidence study also documented any adverse effects occurring during this ten-day period. Results: The median onset of pain relief in the 255 study participants occurred an hour after the first dose of Norgesic® tablet, the fastest by 30 minutes and the slowest by the 8th hour, and it lasted for six (6) hours. At baseline, the median VAS score was seven (7) which subsequently decreased to 0 by day 7 up to day 10 and differed significantly from baseline (p<0.0001). The median number of Norgesic® tablets consumed for pain relief likewise decreased from three tablets on day 1 to one tablet on day 7 to none on the succeeding days until the end of study period. The mean duration of LBP before total resolution, was 5.1 SD ± 2.2 days. The incremental increase in the proportion of those with complete resolution (VAS score=0) was highest by day 7. The median physical disability score significantly decreased to zero (0) on day 11 from nine (9) at baseline. Adverse events reported in 22 participants were generally mild dizziness and somnolence, which lasted for 1-6 days and resolved with rest. Conclusion: In this study, orphenadrine 35 mg + paracetamol 450 mg (Norgesic®) was noted to be effective in alleviating acute nonspecific moderate to severe musculoskeletal LBP of Filipino patients. In addition, Norgesic® aided study subjects in regaining functional capacity for them to continue with their impaired activities of daily living. Only few non-severe, self-limiting adverse reactions were noted during the treatment period.