Cycloserine belongs to the family of medicines called antibiotics. It is used to treat tuberculosis (TB). When cycloserine is used for TB, it is given with other medicines for TB. Cycloserine may also be used for other conditions as determined by your doctor. To help clear up your tuberculosis (TB) completely, you must keep taking this medicine for the full time of treatment, even if you begin to feel better. This is very important. It is also important that you do not miss any doses.