Safety, tolerability and pharmacokinetic study of recombinant human parathyroid hormone [rhPTH (1-84)] in Chinese healthy volunteers.

The current study was designed to determine the safety, tolerability and pharmacokinetic parameters of recombinant human parathyroid hormone [rhPTH (1-84)] used for the treatment of osteoporosis. In the single-dose format pharmacokinetic study, thirty-six healthy male volunteers received three dose levels of rhPTH (1-84) subcutaneously: 1, 2, and 4 microg/kg. The blood was timing drawn and the serum concentration of rhPTH (1-84) was determined by enzyme linked immunosorbent assay (ELISA). Serum concentration-time curves of PTH (1-84) exhibited a double-peak pattern, the first peak appearing about 10 to 30 min after administration and the second peak occurring about 1.5 to 2 h after administration. Serum terminal half-time of PTH (1-84) was approximately 2 h. The parameters indicated the serum levels were directly proportional to the administered dose, with the mean C(max) and AUC(0-24) ranging from approximately 543.47 to 1845 pg/mL and 2358.6 to 9232.12 pg.h.mL(-1) over the dose range. The drug was well tolerated, the clinical symptoms were generally mild and of short duration.