Dose adjustments to existing treatments

The effects of certain drugs can vary greatly based on dosage, making them ideal candidates for repurposing research. Methrotrexate was developed as a chemotherapy drug in the 1950s and has since been administered at a very high dose to cancer patients. At a low dose, and because of totally different mechanisms of the drug, it has become a standard of care for auto-immune diseases such as rheumatoid arthritis (1). Researchers have since ironed the drug’s alternative mechanisms through studies on juvenile idiopathic arthritis (2).

1. Cronstein, BN. Low-dose methotrexate: a mainstay in the treatment of rheumatoid arthritis. Pharmacological Reviews 57(2): 163-72. [Link here]
2. Bulatovic Calasan M., Vastert S.J., Scholman R.C., Verweij F., Klein M., Wulffraat N.M., Prakken B.J., and van Wijk F. (2015). Methotrexate treatment affects effector but not regulatory T cells in juvenile idiopathic arthritis. Rheumatology Feb 2015. [Link here]