Cancer was spread to the rt. lung from the colon. a persistent cough has stared. will a cough supressant do more harm than good?

No.: This is metastatic colon cancer. At this point, you really can't do more harm than good, and whatever treatment that you can get will likely not be affected by it. Anything you can do to alleviate your symptoms will make you more comfortable. If you are still in any doubt you can discuss it with your doctor but it's important the you're as comfortable as possible.

Cough med is ok: If the lung metastasis is in an area that is possibly causing a cough, need to refer to your doctor to know, then a cough suppressant can help. If the lung met is not in the idle region of the lung then it may not be relieved with cough medicine. It ENT so any harm.