they are taken up by osteoclasts and inhibit osteoclastic bone resorption
current available drugs include (in order of potency): (1st gen) etidronate, (2nd gen) tiludronate, IV pamidronate, alendronate (3rd gen) zoledronate and risedronate
all people with cancer-associated hypercalcaemia should receive treatment with bisphosphonates since the first line therapy (above) cannot be continued indefinitely nor is it without risk. Further, even if the first line therapy has been effective, it is a virtual certainty that the hypercalcaemia will recur in the person with hypercalcaemia of malignancy. Use of bisphosphonates in such circumstances, then, becomes both therapeutic and preventative
people in kidney failure and hypercalcaemia should have a risk-benefit analysis before being given bisphosphonates, since they are relatively contraindicated in kidney failure. Denosumab is a bone anti-resorptive agent that can be used to treat hypercalcemia in patients with a contraindication to bisphosphonates such as severe kidney failure or allergy.
Research
It was studied in in vitro and animal models for radiation protection in the 1950s, and in similar models from the 1970s onwards for sickle cell anemia, effects on growth, its ability to modulate the immune system, and as a possible inhibitor of HIV.In the 1970s it was tested in clinical trials for Paracetamol toxicity which it failed, and in clinical trials for systemic lupus erythematosus in the 1990s and early 2000s, which it also failed.Clinical trials in Huntingtons disease were begun in the 1990s and were ongoing as of 2015.As of 2013, it was in clinical trials for Parkinsons disease, malaria, radiation sickness, neurodegenerative disorders, neuropsychiatric disorders, and cancer treatment.It has been studied in clinical trials for pediatric nonalcoholic fatty liver disease

References
External links
"Cysteamine". Drug Information Portal. U.S. National Library of Medicine. "Cysteamine hydrochloride". Drug Information Portal. U.S. National Library of Medicine.