The answer is that they don't try to combat any of these problems. For a patient to meet the criteria for this this kind of therapy they would need to be severely cachectic (which means wasted) and the most common causes of this are cancer, AIDS, TB, or other severe chronic diseases. This means that this is seen as a palliative treatment (makes you comfortable while you die), and therefore long term considerations are not as important.

There are some indications for use of oxandrolone in non chronic disease such as turners syndrome (short stature in female due to genetic anomalies) This therapy is only used short term to induce growth spurts and then the hypothalamic-pituitary-ovarian axis is allowed to find its normal steady state by discontinuing the use of the compound. So in short there is NO pct.