Would you consider PTH analogue in a patient with mildly elevated PTH?

This is a complicated question because there is not any substantial literature. Almost all clinical trials with teriparatide and abaloparatide excluded patients with elevated PTH levels. However, there is considerable anecdotal experience. I have surveyed many colleagues with considerable experience and most feel that pulsatile PTH or PTHrp will still result in an anabolic biology if the PTH is not too high. There is likely a ceiling of PTH levels (maybe greater than 150 pg/ml??) where there will not be an anabolic response. Of course, there needs to be diligent monitoring of Ca levels. In general, TPTD increases Ca absorption by activating Vit D. I usually limit total Ca intake to 800-1000 per day to avoid any hypercalcemia when starting TPTD or abaloparatide. It may be even more important in patients with mildly elevated PTH. To determine if there is an anabolic response I would get a baseline PINP and maybe 2-3 months later retest the PINP. It has been nicely shown that if the PINP increases by >10 mcg/L that you can be confident that the osteoblast has been stimulated to make more bone.

If you have a patient with osteoporosis in whom you are considering treatment with a PTH analog, or indeed any agent, the first step would be to ensure that the patient does not have secondary hyperparathyroidism from Vitamin D deficiency by checking a 25- hydroxy vitamin D level. Once you have done this it would be reasonable to follow the treatment plan as stated by Dr. @Dr. First Last if there is a need to use an anabolic agent.

Perhaps it would be more accurate to say that in a patient with a mildly elevated PTH in whom you are considering treatment with a PTH analog, or indeed any other agent, the first step would be to rule out primary hyperparathyroidism or secondary hyperparathyroidism such as from Vitamin D deficiency, chronic renal disease, etc.