Level 1: Likely reliable evidence
Trigeminal neuralgia is typically treated with chronic therapy, but patients occasionally require treatment for acute pain. Now, subcutaneous sumatriptan (Imitrex) and intranasal lidocaine have each been shown in single-dose trials to reduce pain in the short-term.
Intranasal lidocaine was evaluated in a randomized crossover trial of 25 patients who had severe V2 trigeminal neuralgia for at least three months (Br J Anaesth. 2006;97:559-563). Commercial lidocaine solution 8% in a metered-dose nasal spray device vs. saline nasal spray was administered as a one-time dose consisting of two sprays in the affected nostril of patients lying supine for 30 seconds with neck extended 30-45°. Crossover to the alternate treatment occurred seven days later.
Paroxysmal pain, triggered by touching or moving one’s face, was assessed using a 10-cm visual analog scale (VAS) before and 15 minutes after treatment. A reduction of at least 2 cm in the VAS score occurred in 24 patients (96%) following lidocaine vs. three patients (12%) following placebo (NNT 2); 10 patients were pain-free with lidocaine. The median duration of lidocaine effect was 4.3 hours (range 0.5-24 hours).
Sumatriptan was evaluated in a randomized crossover trial of 24 patients aged 42-80 years with refractory trigeminal neuralgia (Headache. 2006;46:577-582). Patients were administered sumatriptan 3 mg (1 mL) vs. saline placebo (1 mL) subcutaneously and then crossed over to alternate treatment seven days later. The VAS for paroxysmal pain was reduced from 8.3 before to 2.4 at 15 minutes after sumatriptan injection. Pain was moderately or slightly improved after sumatriptan in 20 patients (83%) and after placebo in one patient (4%). The median duration of sumatriptan effect was 7.9 hours (range 1-20 hours).
Neither of these trials provides direct evidence for repeated clinical use, but each suggests a potential role in one-time acute management. It is important for clinicians to avoid triptans in patients with CAD, and caution is recommended in patients with cardiac risk factors (including postmenopausal women or men older than 40 years). Additionally, Imitrex injectable syringes contain 6 mg of the drug, so 3-mg dosing might be difficult.