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Trigeminal neuralgia
SOHAN PAREKH AND ANDY JAGODA
n Agents
n Anticonvulsants
n Baclofen
n Evidence
The anticonvulsants constitute the major drug therapy for trigeminal neural-
gia (TN). Cochrane review has shown that, of the older agents, the treatment of
choice is carbamazapine (200–400 mg PO BID, titrated up to 1200 mg daily
maximum dose). 1 Carbamazepine’s keto-analogoxcarbazepine (300–600 mg
PO BID) is equally effective.
Most of the evidence for carbamazepine’s efficacy in TN comes from the
outpatient setting. However, given the drug’s decades of usefulness, it is a
reasonable first-line choice for ED therapy of TN. 1,2 In addition to its utility in
the general population of patients with TN, carbamazepine is recommended
for treatment of TN in the elderly. 3
Phenytoin and valproic acid can be of some use in TN. Phenytoin is likely
a good second-choice agent, but carbamazepine’s “number needed to treat
for 50% pain relief” of 1.8 reflects its superiority over the other older
anticonvulsants. 1,4,5
Just as carbamazepine incurs certain risks (e.g. blood cell counts and liver
function tests must be monitored), phenytoin’s use in TN is associated with
some chance of side effects such as psychosis. 6 A preliminary case series
found that fosphenytoin helps in acute refractory TN, but the evidence for
this approach remains limited. 7
There are data to suggest utility of new-generation anticonvulsants for TN.
Currently, the main ED role for these agents in TN is for patients who fail to
respond to, or cannot tolerate, single-drug therapy with carbamazepine.Inthe
near future, though, the newer anticonvulsants may replace carbamazepine
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