Stevens-Johnson Syndrome in patients receiving cranial irradiation and concomitant diphenylhydantoin

The routine prophylactic use of anticonvulsants after brain surgery or in patients with brain metastasis without surgery seems to be a variable but common practice, regardless of whether the patient has a previous history of convulsions. Data on the risk of developing adverse drug reactions (ADRs) caused by diphenylhydantoin (DPH) used concomitantly during cranial radiotherapy is still conflicting. Although the exact mechanism is still not well-known, there is increasing anecdotal support in the literature for a synergistic effect between DPH therapy and cranial radiotherapy. Stevens-Johnson Syndrome (SJS) is one of the most severe ADRs which may result with great morbidity and mortality in patients receiving cranial radiation therapy and DPH concomitantly. This report presents 3 cases of this rare syndrome diagnosed in our department in 4 years time. Various authors suggested discontinuation of prophylactic use of anticonvulsants in patients with no history of seizures by emphasizing increased rate of severe mucocutaneous reactions caused by this type of drugs given during radiotherapy, some others have argued in favor of prophylactic anticonvulsants. The risk of seizures reaches 20% to 40% in cases with primary and metastatic brain tumors and the incidence of adverse drug reactions is relatively lower. We believe that the notion rejecting prophylactic anticonvulsant usage in patients with primary or metastatic brain tumors should be evaluated with caution. [Turk J Cancer 2002;32(4):164-171]