Efficacy of serotonin receptor blocker for symptomatic lumbar disc herniation.

Serotonin is one of the chemical mediators associated with nerve root inflammation and sciatic symptoms in lumbar disc herniation. The efficacy of serotonin 5-HT(2A) receptor blocker was examined in 44 patients with symptomatic lumbar disc herniation. A selective 5-HT(2A) receptor blocker (sarpogrelate hydroxychloride) was administered orally at a dose of 300 mg per day for 2 weeks. Visual analog scales of low back pain, sciatic pain, and numbness were significantly improved after the administration of the serotonin 5-HT(2A) receptor blocker. Clinical results were good (> 50% pain relief) in 23 patients, fair (25%-50% pain relief) in five patients, and poor (< 25% of pain relief) in 16 patients. Nineteen patients eventually required surgery because of muscle weakness or cauda equina symptoms. The effect of 5-HT(2A) blocker was good in 64% of patients who had uncontained disc herniation, whereas all patients with contained disc herniation had fair or poor results. Patients with uncontained disc herniation responded more favorably to the 5-HT(2A) blocker treatment than patients with contained disc herniation. A 5-HT(2A) blocker has the potential to block the cascade of acute nerve root inflammation and to alleviate symptoms in lumbar disc herniation.