<prompt> An agent of choice in acute hypercalcemia due to malignancy isCalcitoninCholecalciferolTeriperatideZolendronate  <response>: Calcitonin is the fastest acting followed by I.V bisphosphonates. hyperccalcimia in malignancy is mainly seen in tumors secreting Parathyroid hormone related peptide PTHrP. Ref: CMDT pg 801 2010 ed. 