Pharmacokinetics and safety of recombinant human parathyroid hormone (1-34) (teriparatide) after single ascending doses in Chinese healthy volunteers

The pharmacokinetics and safety of recombinant human parathyroid hormone (1-34) rhPTH (1-34)] after single ascending doses were evaluated in Chinese healthy volunteers. Nine healthy volunteers (five male and four female) were recruited for an open label, randomized, three multiply three crossover, single ascending dose (10, 20, and 40 microg) study. Using a validated radioimmunoassay, we determined the plasma concentrations of rhPTH (1-34). The mean peak plasma concentration (Cmax) were 123.6, 195.6, and 318.2 pg x mL(-1) respectively, and were reached from 25.6 to 36.1 min after subcutaneous administration. After Cmax was reached, the plasma drug level decreased quickly, with elimination halflife (t(1/2)) of 53.9 to 64.1 min. The mean AUC(0-infinity) (the area under the plasma concentration versus time curve from time zero to infinite) of rhPTH (1-34) were 11794.2 +/- 974.8, 21606.7 +/- 4753.9, 33877.0 +/- 8374.4 pg x min x mL(-1), respectively. The mean AUC(0-t) (the area under the plasma concentration versus time curve from time zero to the last quantifiable concentration) of rhPTH (1-34) were 9034.4 +/- 1073.9, 17883.3 +/- 4597.1, 31693.5 +/- 6574.8 pg x min x mL(-1), respectively. Dose-related linear trend were observed for AUC(o-t) and Cmax of rhPTH (1-34). t(1/2) and Tmax (time to Cmax) of rhPTH (1-34) were independent of administered dose. rhPTH (1-34) was safe and well tolerated by all volunteers.