This phase II trial studies how well giving oxaliplatin and pemetrexed disodium together works in treating patients with refractory hormone-resistant prostate cancer. Drugs used in chemotherapy, such as oxaliplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Pemetrexed disodium may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving oxaliplatin together with pemetrexed disodium may kill more tumor cells.