We need to treat a patient with cerebral toxoplasmosis with pyrimethamine because he is allergic to trimetoprim-sulfamethoxazole. We only have 100 mg/10 ml vials of leucovorin/calcium folinate in Romania and the recommended dose is 10-25 mg/day. Any idea on whether this form of drug can be swallowed? How long we can use an opened vial? The product summary characteristics indicates that a diluted vial should be kept at room temp for max 24 hours and the undiluted drug should be kept in the fridge. I don't understand why we have such a large amount of drug per vial when all we need is a max of 25 mg/day, even for cytotoxic treatment with methotrexate. Does the farmacodynamics of the drug support administrations every few days (the idea being that we would administer 100 mg every few days)?