ObjectiveTo study the pharmacokinetics of lovastatin/niacin sustained-release tablets in healthy Chinese volunteers. MethodsEligible subjects were enrolled to receive a single dose of 20/500, 20/750 and 20/1 000 mg lovastatin/niacin sustained-release tablets and multiple dose of 20/1 000 mg lovastatin/niacin sustainedrelease tablets, one time per day, sustained for 5 days, respectively. Blood samples were obtained before dosing and up to 10, 20, 30, and 45 minutes, and 1 hour, 1.5, 2, 2.5, 3, 3.5, 4, 5, 7, 9, 12, and 15 hours after dosing. Niacin, niacinamide, nicotinuric acid and lovastatin were detected by high performance liquid chromatography-tandem mass spectrometry method. ResultsThe peak concertration and the area under the plasma concentration-time curve (0-t) of nicotinuric acid had linear dynamics characteristics with the dosage when the dose of niacin was between 500 and 1 000 mg. After multiple dosing, pharmacokinetics parameters of nicotinuric acid and lovastatin were close. No significant diTherence was found between male and female subjects. ConclusionLovastatin/niacin sustained-release tablets possess linear kinetics. Accumulation is not significant after multiple dosing. Gender doesn't affect the pharmacokinetics parameters.
ObjectiveTo evaluate the reasonableness of anticoagulation management strategy in patients after mechanical heart valve replacement. MethodsAll patients were followed and registered continually at outpatient clinic from July 2011 to February 2013, with a minimum of 6 months after surgery. Targeted international normalized rate (INR) 1.60 to 2.20 and warfarin weekly dosage adjustment were used as the strategy of anticoagulation management. Except bleeding, thrombogenesis and thromboembolism, time in therapeutic range (TTR) and fraction of TTR (FTTR) were adopted to evaluate the quality of anticoagulation management. ResultsA total 1 442 patients and 6 461 INR values were included for data analysis. The patients had a mean age of 48.2±10.6 years (14-80 years) and the following up time were 6 to 180 months (39.2±37.4 months) after surgery. Of these patients, 1 043 (72.3%) was female and 399 (27.7%) was male. INR values varied from 0.90-8.39 (1.85±0.49) and required weekly doses of warfarin were 2.50-61.25 (20.89±6.93 mg). TTR of target INR and acceptable INR were 51.1% (156 640.5 days/306 415.0 days), 64.9% (198 856.0 days/306 415.0 days), respectively. FTTR of target INR and acceptable INR were 49.4% (3 193 times/6 461 times), 62.6% (4 047 times/6 461 times). There were 8 major bleeding events, 7 mild bleeding events, 2 thromboembolism events, and 2 thrombogenesis in the left atrium. ConclusionIt is reasonable to use target INR 1.60-2.20 and warfarin weekly dosage adjustment for patients after mechanical heart valve replacement.