Temozolomide treatment does not affect topiramate and oxcarbazepine plasma concentrations in chronically treated patients with brain tumor-related epilepsy

Marta Maschio, Fiorenzo Albani, Bruno Jandolo, Alessia Zarabla, Manuela Contin, Loredana Dinapoli, Alessandra Fabi, Andrea Pace, Agostino Baruzzi

Research output: Contribution to journalArticle


Objective: Medical management of brain tumor-related epilepsy is complicated by interactions between antiepileptic and chemotherapeutic drugs. We studied the effect of temozolomide therapy on the disposition of the new antiepileptic drugs topiramate (TPM) or oxcarbazepine (OXC). Methods: Fifteen patients chronically treated with TPM or OXC in monotherapy starting a chemotherapeutic treatment with temozolomide were enrolled in the study, of which ten were available for the final analyses. Blood samples were collected before temozolomide treatment (T0), at its end (T7) and after further 1-3 weeks (T14-T28). For each patient, more than one treatment cycle was studied. Topiramate and OXC mono-10-hydroxy derivative (MHD) plasma concentrations were determined by hplc coupled with ion spray mass spectrometer (TPM) or ultraviolet (MHD) detection. Results: Mean TPM concentrations were 5.4 ± 2.4 μg/ml at T0 vs. 5.5 ± 2.4 μg/ml at T7 (n = 14), and 5.4 ± 2.4 mu;g/ml at T0 vs. 5.6 ± 2.8 μg/ ml at T14-T28 (n = 14). Mean MHD concentrations were 16.4 ± 7.6 μg at T0 vs. 18.5 ± 9.0 μg/ml at T7 (n = 5), and 16.8 ± 7.0 mu;g/ml at T0 vs. 18.0 ± 8.7 μg/ml at T14- T28 (n = 8) (all comparisons not statistically significant; Student's t-test for paired samples). Conclusion: Temozolomide treatment did not affect TPM plasma concentrations in chronically treated patients. Data for MHD in OXC-treated patients were similar, but, due to the small sample size, results should be interpreted cautiously.These findings confirm that TPM (and possibly OXC) are a reasonable choice of antiepileptic drug in patients with brain tumor-related epilepsy.

Original languageEnglish
Pages (from-to)217-221
Number of pages5
JournalJournal of Neuro-Oncology
Issue number2
Publication statusPublished - 2008



  • Brain tumor-related epilepsy
  • Drug interactions
  • Oxcarbazepine
  • Temozolomide
  • Topiramate

ASJC Scopus subject areas

  • Clinical Neurology
  • Cancer Research
  • Oncology
  • Neurology

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