Neuroleptic malignant syndrome associated with atypical antipsychotics: A case report

Neuroleptic malignant syndrome (NMS) is uncommon, with an incidence of 0.01%-3.23%, and is associated with the use of drugs that intervene with dopamine, causing hyperthermia, muscular rigidity, confusion, autonomic instability and death.

A 35-year-old man with a history of catatonia, refractory epilepsy and functional impairment, required frequent changes in his anticonvulsant and antipsychotic treatment, due to adverse effects. During 2019, in the month of July, clozapine was changed to amisulpride, in September he developed fever, muscle stiffness, stupor, diaphoresis and tachypnea over a two-week period; paraclinical tests showed elevated creatine phosphokinase (CPK) and leukocytosis, so NMS was considered. The antipsychotic was withdrawn and he was treated with bromocriptine and biperiden, with a good response. Ten days after discharge, he began treatment with olanzapine, which generated a similar episode to the one described in December, with subsequent management and resolution.

The diagnosis is based on the use of drugs that alter dopamine levels, plus altered state of consciousness, fever, autonomic instability and paraclinical tests showing leukocytosis and elevated CPK. Differential diagnoses must be ruled out. Early diagnosis generally leads to total remission, although some patients will suffer complications, long-term sequelae or recurrences. The recurrence in this case derived from the early reintroduction of the neuroleptic after the first episode. Treatment should be individualised according to severity to avoid mortality.

Atypical antipsychotics are rarely suspected of generating NMS. Moreover, the time to reintroduction after an episode must also be taken into account.