Sumatriptan alleviates pain in patients with trigeminal neuralgia

Arterial compression of the trigeminal root may lead to trigeminal neuralgia. 5-HT1B/1D receptor agonists may inhibit vasodilation and inflammation near the irritated trigeminal root. A recent study showed attenuation of mechanical allodynia by a 5-HT1A receptor agonist in a rat model of trigeminal neuralgia. The present study examined the effectiveness of a 5-HT1A/1B/1D receptor agonist, sumatriptan, on pain relief in patients with trigeminal neuralgia.

The study was conducted in 15 patients with idiopathic trigeminal neuralgia. The patients had been suffering from painful paroxysms for at least 1 month. Each patient was injected with 1 mL of saline subcutaneously (placebo), followed 15 minutes later with subcutaneous sumatriptan (3 mg in 1 mL saline). This was followed the next day by oral sumatriptan (50 mg twice daily) for 1 week.

The visual analog scale did not change after saline, but significantly decreased after subcutaneous sumatriptan. Both 1 week after oral sumatriptan and 1 week after discontinuation of the drug, visual analog scale scores resulted in a significant decrease from the baseline. Adverse events after subcutaneous sumatriptan occurred in 4 patients: fatigue in 4 and nausea in 2. Side effects from the oral medication appeared in 4 patients: fatigue in 2, nausea in 1 and chest discomfort in 1. These side effects subsided soon after discontinuation of sumatriptan.

Our results indicate that subcutaneous injection followed by oral administration of sumatriptan produces prompt and continuous analgesia in patients with trigeminal neuralgia.