My 49 year old husband has COPD and after long term use of steriods he developed Avascular Necrosis AVN. This led to a partial replacement of his humerus which then caused a spiral fracture. Forteo was prescribed to speed the re-growth in his weakened bones, and worked. Full dosage of daliy injections caused extreme cramping in his calves and chest and was reduced to every other day. However, if he missed another day, the cramping would come back with vengence as if it were a withdrawal symptom? However, I have noticed that since the 2 years ended a few months ago and he stopped Forteo, his breathing has worsened gradually, even tho he gave up smoking before he came off the Foreo and this helped greatly. I am wondering if, now he is not having the hormone in Forteo, that somehow this is having an adverse effect on his lungs. Has anyone else found that Forteo use enhances lung function in anyway? Also, his cramping is now back with vengence and we are unclear if this has got worse because he is no longer on Forteo. Dr and Pulmonologist are not very helpful. Steriod use also caused exteme cramping. Comments would be appreciated. annie