My dad, 84 years old, was given this drug for a lung infection ca...

My dad, 84 years old, was given this drug for a lung infection caused by an undiagnosed agent. That was the first mistake as it had no effect on his condition (The shotgun in the dark approach). I do not know the dose are length of time it was taken. Hopefully not very long. Now hospitalized, barely able to walk. General weakness, vision deteriorating, Carpal Tunnel like symptoms, swollen ankles, pain in shoulder, loss of appetite and subsequent weight loss, and who knows what else. Seemed to be pessimistic about recovery, negative thoughts. "Cannot go on like this" so went to hospital. What a tragedy, turning a vibrant elderly person into practically an invalid. Perhaps effects wiil wear off. Any ideas?