Drug interactions of old antiepileptic drugs with antidepressants and antipsychotics

Interacciones medicamentosas de los anticonvulsivantes de primera línea con antipsicóticos y/o antidepresivos

Objective: Identify drug interactions of old antiepileptic drugs with antidepressants and antipsychotics and its impact on the patient with epilepsy at the Hospital de San José in outpatient appointment from June 1 st, 2015 to the april 30th, 2016.
Material and methods: A descriptive study was conducted to identify drugs interactions in patients diagnosed with epilepsy. The study involved patients over 18 years old with a diagnosis of epilepsy according to the International League Against Epilepsy criteria in therapy with first line antiepileptic drugs associated with antipsychotic drugs or/and antidepressants, excluded pregnant women, patients with hepatic and renal impairment. The statistic analysis of qualitative variables was performed using absolute and relative frequencies. Quantitative variables were analysed using medians and interquartile ranges.
Results: We included 26 patients with a median age of 49 years (IQR: 33-57), 14 were women (53.8%). The most relevant conditions on past medical history were perinatal hypoxia and brain trauma, both diagnosed on 5 patients (19.2%). The most frequently anticonvulsant monotherapy used was carbamazepine, which was prescribed on 8 patients (30.8%). Only two patients receiving carbamazepine presented leucopenia. None of the patients presented elevated liver enzymes. Anticonvulsant serum levels in most therapies were within the therapeutic range.
Discussion and conclusions: We described multiple combinations of anticonvulsants with antipsychotics and/or antidepressants. No liver toxicity or serious hematologic abnormalities that could suggest a change on the therapy was documented. Furthermore, most anticonvulsants serum concentration remained within the therapeutic range.

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