Evidence-based pharmacotherapy for trigeminal neuralgia
| Drug | Dosage regimen | Usual dose range | Common side effects |
|---|---|---|---|
| First-line therapy | |||
| Carbamazepinea | 100 mg twice daily; double after 3 days to 200 mg twice daily; increase by 100–200 mg twice daily every 3 days, then 200 mg 4 times daily | 800–1,200 mg daily | Sedation, dizziness, blurred vision, nausea, unsteady lethargy, double vision, headache May cause hyponatremia, skin rashes, pancytopenia Risk of osteoporosis with long-term use May reduce oral contraception efficacy |
| Oxcarbazepinea | 150 mg twice daily, double to 300 mg twice daily after 3 days; increase by 150–300 mg twice daily every 3 days, then 300 mg 4 times daily | 1,200–1,800 mg daily | Drowsiness, dizziness, diplopia, confusion, nausea, abdominal pain, headache, depression, diarrhea High risk of hyponatremia Chronic use risks osteoporosis May reduce oral contraception efficacy |
| Second-line therapy | |||
| Lamotrigine | Start 25 mg a day for 7 days, then 25 mg twice daily for 7 days, then 50 mg twice daily for another week; subsequent dose increments of 50 mg every 7 days, up to 10 weeks | 200 mg twice daily | Blurred vision, agitation, aggression, unsteadiness, dizziness, nausea, dry mouth, insomnia, joint pains Risk of skin rashes and Stevens-Johnson syndrome with rapid dose escalation Probably safe for pregnant women at a dose of 100 mg twice daily |
| Baclofen | 5 mg 3 times daily for 3 days, then increase to 10 mg 3 times daily for 3 days; increase by 10 mg 3 times daily every 3 days until maximum dose | 40–80 mg daily | Anxiety, depression, agitation, unsteadiness, headache, sedation, tremor, skin rash, blurred vision, dry mouth, abdominal pain, withdrawal symptoms if stopped too rapidly |
| Gabapentin | 100 mg 3 times daily day 1, 200 mg 3 times daily day 2 and 300 mg 3 times daily day 3. Increase by 1-300 mg 3 times daily every 3 days to maximum dose; start 100 mg 3 times daily or 300 mg at bedtime; can increase dose up to 300 to 600 mg 3 daily | 900–3,600 mg daily | Amnesia, confusion, dizziness, vertigo, drowsiness, depression, nausea, blurred vision, peripheral edema, constipation, abdominal bloating, weight gain |
| Pregabalin | 25 mg twice daily; increase by 25–50 mg twice daily every 3 days | 600 mg daily | Confusion, drowsiness, constipation, blurred vision, dizziness, nausea, peripheral edema, increased appetite, weight gain |
↵a Carbamazepine and oxcarbazepine are available in liquid form. Dosage ranges vary due to lack of high-quality trials.