Just a question on rifinah... My dad has been on anti-tb treatment since he was diagnosed, about two months ago. Of course he's no longer infectious and he's shown improvement (gained many pounds, no longer coughs as much etc.) and he's been under doctor screening as well (x-rays, blood tests etc.).

My question has to do with a drug he's taking, rifinah. (he's taking some other drugs as well but i'm not at home and I don't remember their names, sorry). While at first his urine used to turn orange from the drug, for the past couple of days the coloring is not as intense and / or disappears completely. His feces are still coloured.

Does the loss of coloring have anything to do with the drug working or not? Is there a chance he might have developed any kind of resistance to the drug or is coloring just a side effect that may come and go like that? I'd like to stress he's been taking all his medication as ordered and never skips any.

Thanks.