Pemetrexed and communicating hydrocephalus

Background: Pemetrexed (Alimta) is widely used in combination with platinum as a first-line treatment of mesothelioma and adenocarcinoma of the lung. It is also approved for use in the maintenance setting as a single agent after patient completion of 4 to 6 cycles of a platinum-based doublet regimen for non- small cell lung cancer. With the increasing use of pemetrexed and longer durations of therapy, unexpected cumulative toxicity or other toxicities are possible. Case Report: We report a case of a patient receiving maintenance pemetrexed for advanced adenocarcinoma of the lung who developed communicating hydrocephalus. Conclusion: We are not aware of any other reports of communicating hydrocephalus in association with pemetrexed therapy. As more patients routinely receive pemetrexed as maintenance therapy, the development of toxicities or unexpected diagnoses is possible and may be a consideration in the chronic management of such patients.