Fosphenytoin: an intravenous option for the management of acute trigeminal neuralgia crisis.

Timely management of trigeminal neuralgia presenting with severe, sustained, crescendo pain can be difficult with oral medications. More rapid pain control often can be achieved using intravenous phenytoin. Fosphenytoin is a phosphate ester prodrug of phenytoin that is significantly better tolerated parenterally than phenytoin in the treatment of epilepsy. Three patients with trigeminal neuralgia refractory to oral medications and presenting with crisis pain were treated urgently with intravenous fosphenytoin. In each case complete relief of pain was achieved for a duration of two days, affording a window of opportunity to modify oral pharmacotherapeutic strategies or to control pain in preparation for invasive neurosurgical intervention.