Uncontrolled headache induced by oxcarbazepine.

Headache induced by acute exposure to a specific drug constitutes an idiosyncratic side effect. Metabolic imbalance appears as the leading aetiology, among several other hypotheses. Either primary headaches show a higher susceptibility to this idiosyncratic reaction or a drug-induced primary headache evolves in intensity and duration, becoming uncontrolled until the complete discontinuation of the drug in consideration. The goal of this study is to describe three patients diagnosed with migraine and epilepsy (both under control) who evolved into status migrainosus after the introduction of oxcarbazepine (OXC), as part of a switch off from carbamazepine (CBZ). Twenty-four to seventy-two hours following the switch, all patients developed intractable headache, despite the use of different symptomatic drugs. Complete recovery of the headache symptoms occurred only after OXC was discontinued. We discuss the potential mechanisms associated to OXC and status migrainosus, drug-induced headaches and uncontrolled headaches.