Fox trot symptoms and conditions

My father who is 82 was given Levaquin after a Urinary Tract Procedure. After 3 doses became very sick. He was taken to the E.R. in an ambulance with heart palpitations, trouble breathing, sweating, loose stools and confusion. At the hospital the doctor put him on an I.V. drip of Levaquin and wrote out a prescription for my mother to fill for more Levaquin which she administered to him herself.
When I arrived at the hospital he was able to relate to me that his symptoms began while taking the Levaquin. I checked the internet and found hundreds of testimonials against this drug. Needless to say I had the drug discontinued immediately and got him out of that doctor's care and out of the hospital. His health has improved greatly, but he is depressed, tired, and is not himself at all.
This man was an intellegent and vibrant person who danced the fox trot at his grand daughter's wedding just a month ago.
Today he admitted to me that his abilty to reason and remember things has been coming and going. He insists that it all began with his taking the Levaquin. I, for one, believe him one hundred percent.
My question is how can we get this poison out of his system?
I am a great believer in natural medicines and therapies. Has anyone tried anything that has helped.