You can't reverse it but you can stop it from getting worse with weight bearing exercise (body weight) and use of free weights to strengthen individual muscles.
Google: osteopenia and exercise.
I actually have osteoporosis. I walk a treadmill and lift 5 pound weights (squats, various arm lifts
sit ups)
Good wishes!😊

Peggy theres no need to be sorry, i was prescribed and seemingly abandoned on Phenytoin for 30 years.

You like to see Prolia injections for strengthening the bones . Every 6 months

Hey wait one minite because we don't fully know the situation,eg Phenytoin for me controlled my seizures due to being very effective. The problem for me was a breakdown in communication which did result in my toxic levels, which in turn is poisonous and harmful. Monitor Phenytoin levels or you may regret it, i believe it should between 10-20 mg/L mine was well out of this fine range and thats one the problems its-a-fine-range.
I have tried some other medications and I will have to try more, I wish you good health.

Physical Therapy is strenuous. I came home and took a 3 or 4 hour nap...lost track.
3lb ankle weights are a lot for this skinny body. When they work me up to 5lbs I don't know how I'll do.