OBJECTIVE: We aimed to investigate the effect of oral magnesium supplementation for acute low back pain.
METHODS: This is a three-arm, prospective randomized open label clinical trial, which included two hundred and forty patients. We based our sample size calculation assumptions on a recently published clinical trial, thus we enrolled 80 patients for each group. NSAID alone group included (400 mg etodolac twice a day), NSAID + mg group included NSAID - magnesium combination treatment (400 mg etodolac twice a day with 365 mg oral magnesium supplementation) and NSAID + paracetamol group included NSAID - paracetamol combination treatment (400 mg etodolac twice a day with 500 mg paracetamol twice a day). Follow-up visits after initiation of relevant treatment were performed at 4th and 10th days and outcome measures included pain (Visual analogue scale - VAS), mobility of lumbar spine and functional outcome (RMDQ).
RESULTS: Thirty-one patients were considered lost to follow-up or excluded due to use of other medications and final analysis was performed with 209 participants in three groups (71 patients in NSAID alone group, 68 patients in NSAID + mg group and 70 patients in NSAID + paracetamol group). NSAID + mg showed a significantly higher improvement in RMDQ and VAS scores at acute stage (at 4th day visit) compared to two other study groups However, there was no significant difference between three groups in terms of mean improvement of RMDQ, VAS scores and lumbar mobility between initial visit and 10-day.
CONCLUSION: Results of this study suggest that addition of magnesium to acute low-back pain treatment does not significantly improve final clinical outcomes.
LEVEL OF EVIDENCE: Level I, prospective randomized controlled study.
Too many lost to follow-up, which weakens the power calculation.
This prospective RCT evaluated etodolac 400 mg (an NSAID) vs NSAID with magnesium 365 mg vs NSAID with paracetamol 500 mg using visual analogue scale (VAS) and mobility of lumbar spine and functional outcome (RMDQ). he authors excluded patients who received IV or IM analgesia during the treatment period. There was improvement at 4 days in VAS and RMDQ scores for patients receiving NSAID with Mg, but no difference between groups at 10 days. The study was unblinded, and authors did not assess other analgesic drugs for low back pain at the time of enrollment. Further study is needed evaluating magnesium for acute pain.
The minimum clinically important improvement of 5 points on the RMDQ and the difference was only 2.7 between NSAID alone and NSAID and magnesium. However, there was a trend. I agree with the authors that more research is needed.