What should I know about ethionamide before taking it?

You should start to feel better after a few weeks of starting ethionamide. However, you MUST continue taking it regularly for as long as your doctor prescribes it, which is usually nine months but can be a year or two. If tuberculosis treatment regimens are not followed completely, the tuberculosis can become resistant to the available drugs. Drug resistant Mycobacterium tuberculosis is very bad. There is a risk that ethionamide could damage your nerves, especially in your eyes, so while you are taking it you will have regular eye examinations. There also is a risk of liver damage, so you will have monthly blood tests of your liver function. You also will have periodic tests of your thyroid function and glucose levels, which are affected in some people who take ethionamide. There were birth defects reported in studies of pregnant animals. There have been no definitive studies of the safety or effectiveness of ethionamide in children.