This should be an easy fix if he's still eating. For now I would stop all other medication, and stick with the 3% epsom salt infused pellets as described in the link previously posted.
For a 3% solution of Magnesium sulphate, add 1 level tablespoon (15 grams) magnesium sulphate to 500 milliliters of distilled water. Stir, and it's good to go.
Use an eye dropper or pipette to add to pellet food (or any other food that will readily absorb it), and stop dripping water once the pellets become saturated. Use only enough water to saturate the food, with no excess water, so that the water soluble vitamins in the food remain intact. Feed twice a day, for 5 days.