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1.
OBJECTIVE: Pharmacokinetic data on glucosamine are scant, limiting the understanding of glucosamine sulfate mechanism of action in support of its treatment effects in osteoarthritis. This study investigated the oral pharmacokinetics and dose-proportionality of glucosamine after administration of the patented crystalline glucosamine sulfate in man. METHODS: Twelve healthy volunteers received three consecutive once-daily oral administrations of glucosamine sulfate soluble powder at the doses of 750, 1,500, and 3,000 mg, in an open, randomised, cross-over fashion. Glucosamine was determined in plasma collected up to 48 h after the last dose by a validated Liquid Chromatography method with Mass Spectrometry detection. Pharmacokinetic parameters were calculated at steady state. RESULTS: Endogenous plasma levels of glucosamine were detected (10.4-204 ng/ml, with low intra-subject variability). Glucosamine was rapidly absorbed after oral administration and its pharmacokinetics were linear in the dose range 750-1,500 mg, but not at 3,000 mg, where the plasma concentration-time profiles were less than expected based on dose-proportionality. Plasma levels increased over 30-folds from baseline and peaked at about 10 microM with the standard 1,500 mg once-daily dosage. Glucosamine distributed to extravascular compartments and its plasma concentrations were still above baseline up to the last collection time. Glucosamine elimination half-life was only tentatively estimated to average 15 h. CONCLUSIONS: Glucosamine is bioavailable after oral administration of crystalline glucosamine sulfate, persists in circulation, and its pharmacokinetics support once-daily dosage. Steady state peak concentrations at the therapeutic dose of 1,500 mg were in line with those found to be effective in selected in vitro mechanistic studies. This is the only glucosamine formulation for which pharmacokinetic, efficacy and safety data are now available.  相似文献   

2.
Intravenous pamidronate is frequently used for the treatment of osteoporosis in patients who cannot tolerate oral bisphosphonates. The aim of the present study was to compare the changes in bone mineral density (BMD) after 1 year of treatment with either oral alendronate or intravenous pamidronate in patients with osteoporosis. We studied 40 consecutive patients starting treatment for osteoporosis: 20 received oral alendronate 10 mg/day and 20 received intravenous pamidronate 60 mg/3 months. Patients were started on intravenous pamidronate in the case of intolerance (within 1 month of start of treatment) of an oral bisphosphonate or in the case of contraindications for an oral bisphosphonate. BMD (spine and total hip) was measured with dual X-ray absorptiometry (DEXA) at the start of treatment and after 1 year. The BMD of the lumbar spine increased by 4.0% (P<0.05 vs baseline) in both groups, and the BMD of the hip increased by 3.3% and 2.9% (P<0.05 vs baseline) in the alendronate and pamidronate groups, respectively. The increases in BMD of the vertebral spine and the total hip after 1 year are comparable in the alendronate and pamidronate groups. We conclude that intravenous pamidronate can be used successfully as an alternative treatment in patients with gastrointestinal intolerance of an oral bisphosphonate.  相似文献   

3.
Bone loss is a known complication of severe burn injury. It is, in part, due to increased endogenous glucocorticoids that contribute to the reduction in bone formation and osteoblast differentiation, hypercalciuria secondary to hypoparathyroidism, and vitamin D deficiency. In this study we attempted to prevent post-burn bone loss by acute intravenous administration of the bisphosphonate pamidronate. We enrolled 43 children, with burns of >40% total body surface area, in a randomized, double-blind, placebo-controlled study, administering the study drug within 10 days of burn injury and again 1 week later. Dual energy X-ray absorptiometry was performed prior to drug therapy, at hospital discharge and at 6 months post-burn. Urine specimens were obtained at baseline and discharge for determination of calcium and free deoxypyridinoline. Blood was obtained along with the urine specimens for measurement of intact parathyroid hormone (iPTH) and ionized calcium (Ca) levels. Following doxycycline labeling, intra-operative iliac crest bone biopsies were obtained, and bone histomorphometry was determined. At time of discharge there were no differences in total body bone mineral content (BMC), but lumbar spine BMC was significantly higher in the pamidronate group (P<0.005). By 6 months post-burn the differences in lumbar spine BMC persisted, but, now, total body BMC was significantly higher in the pamidronate group (P<0.05). Bone histomorphometry and levels of urine Ca and free deoxypyridinoline failed to show significant increases in bone formation or decreases in bone resorption. Pamidronate did not exacerbate the hypocalcemia in burn patients. In summary, acute intravenous pamidronate administration following burns may help to preserve bone mass, perhaps by inhibiting the glucocorticoid-induced apoptosis of osteoblasts and osteocytes.  相似文献   

4.
Muscle atrophy and bone loss pose substantial problems for long-term space flight and in clinical immobilization. We therefore tested the efficacy of flywheel resistive exercise and pamidronate to counteract such losses.

Twenty five young healthy males underwent strict bed rest with −6° head-down tilt for 90 days. Subjects were randomized into an exercise group that practiced resistive exercise with a ‘flywheel’ (FW) device every 2–3 days, a pamidronate group (Pam) that received 60 mg pamidronate i.v. 14 days prior to bed rest and a control group (Ctrl) that received none of these countermeasures.

During the study, Ca++ and protein intake were controlled. Peripheral quantitative computed tomography (pQCT) was used to assess bone mineral content (BMC) and muscle cross sectional area (mCSA) of calf and forearm. Measurements were taken twice during baseline data collection, after 28 and after 89 days bed rest, and after 14 days recovery. On the same days, urinary Pyridinoline excretion and serum levels of alkaline phosphatase, Ca++ and PTH were measured. Pre-study exercise habits were assessed through the Freiburg questionnaire.

Losses in calf mCSA were significantly reduced in FW (Ctrl: −25.6% ± 2.5% Pam: −25.6% ± 3.7%, FW: −17.3% ± 2.7%), but not in the forearm mCSA (Ctrl: −6.4% ± 4.33%, Pam: −7.7% ± 4.1%, FW: −7.6% ± 3.3%). Both diaphyseal and epiphyseal BMC losses of the tibia were mitigated in Pam and FW as compared to Ctrl, although this was significant only at the diaphysis.

Inter-individual variability was significantly greater for changes in BMC than in mCSA, and correlation of BMC losses was poor among different locations of the tibia. A significant positive correlation was found between change in tibia epiphyseal BMC and serum cortisol levels.

These findings suggest that both countermeasures are only partly effective to preserve BMC (FW and Pam) and mCSA (FW) of the lower leg during bed rest. The partial efficacy of flywheel exercise as well as the bones' response to unloading per se underlines the importance of mechanical stimuli. The huge variability of BMC changes, however, suggests that other factors affect changes in whole-bone strength following acute mechanical disuse.  相似文献   


5.
In this trial we studied the effect of pamidronate on periprosthetic bone turnover and pelvic implant migration over 2 years after hybrid total hip arthroplasty (THA). Twenty-two patients received 90 mg of pamidronate and 22 received placebo at randomization 5 days after surgery. Rapid periprosthetic bone loss occurred in the placebo group over the first 6 months and was accompanied by transient increases in biochemical markers of bone turnover. Partial recovery in bone mass occurred in most regions after this period. No recovery of bone mass occurred at the femoral calcar or the medial wall of the acetabulum. Femoral calcar bone loss at 2 years was strongly predicted by acute biomarker changes at week 6. Pamidronate therapy reduced femoral bone loss in the region of the femoral calcar (P = 0.01), but did not affect pelvic bone loss. Pamidronate therapy also inhibited the transient rise in biochemical markers of bone turnover during this period. Pamidronate therapy did not affect acetabular cup migration. Cup migration was inversely related to subject age, but unrelated to initial post-operative bone mineral density, or subsequent bone loss. In summary, early periprosthetic bone loss is associated with a transient expansion of the bone remodeling space. Bisphosphonate therapy reduces femoral calcar bone loss and bone turnover after THA, but did not influence cup migration in this study. Acute changes in biochemical markers predict femoral periprosthetic bone loss.  相似文献   

6.
Complications in fracture repair that lead to a delay in union remain clinically problematic. We believe that unwanted pre-mature catabolism of the healing callus, for example, in stress shielded situations, diminishes the rate at which strength is restored in bone repair and possibly leads to delayed union. We hypothesized that a single systemic dose of a nitrogen-containing bisphosphonate (N-BP) would increase bone mineral content (BMC), volume, and mechanical strength of union in fracture repair. We also set out to investigate local delivery to assess whether systemic exposure could be eliminated, due to concerns of bisphosphonate dosing of non-target organs. After an open osteotomy fixed with a K wire, 40 12-week old Wistar male rats were divided into four groups of 10: saline control, bolus systemic subcutaneous injection of pamidronate (3 mg/kg), local low dose of pamidronate (0.1 mg), and a local high dose of pamidronate (1.0 mg). Rats were sacrificed 6 weeks post-operatively. Operated and non-operated femora underwent radiographic evaluation, quantitative computer tomography, and biomechanical testing in torsion. The growth plates and metaphyses of the tibia of the non-operated side were assessed for evidence of systemic exposure in the local groups. Significant increases in callus BMC and volume of the bolus systemic dose group were found compared to the saline control (p< or =0.05). Further, the strength of the systemic dose callus was increased by 60% from 0.35 Nm (+/-0.11) for the saline control callus to 0.56 Nm (+/-0.25) for the systemic group (p=0.05). Local treatment did not result in increased strength. The contralateral tibial growth plates of the local groups showed evidence of systemic exposure by the presence of retained primary spongiosa. This study confirms that a single perioperative systemic dose of pamidronate leads to significant increases in the BMC, volume, and strength of healing fractures in rats, making single dose N-BP therapy an appealing candidate for further examination in fracture repair.  相似文献   

7.
OBJECTIVE: To evaluate oral single dose prophylaxis in colorectal surgery. DESIGN: Prospective study. SETTING: University hospital, Sweden. SUBJECTS: 24 patients (13 women; 11 men; mean age 57 years, range 27-81) listed for elective colorectal operations. INTERVENTION: At 0630 on the day of the operation all patients were given an oral dose of trimethoprim-sulphamethoxazole (TMP 160 mg and SMZ 800 mg) and metronidazole (2 g). The serum concentrations of TMP and SMZ were analysed in venous samples taken at the start and end of each operation. RESULTS: The earliest operation started at 0830 and the last finished at 1700. The median (range) serum concentrations of TMP were 1.4 (0.7-2.6) mg/L (start) and 1.3 (1.0-2.8) mg/L (end), and of SMZ 35 (15-65) mg/L (start) and 33 mg (13-70) mg/L (end). The individual values were above or equal to the minimal inhibitory concentration (TMP 0.8 mg/L; SMZ 15.2 mg/L) for relevant gram-negative species. CONCLUSION: Oral TMP/SMZ in the morning gives satisfactory serum concentrations independently of when the operation is done during the day. The regimen is simple and has the potential for being an effective alternative to intravenous prophylaxis.  相似文献   

8.
In cynomolgus and rhesus monkeys, the dose-normalized exposure of cyclosporine administered orally as microemulsion preconcentrate (Neoral) was lower than that upon intramuscular administration. For oral administration, mean values ( ± SD) of Cmax, 24-h area-under-the curve (AUC) and 24-h trough level, all normalized for a 1 mg/kg dose, were 20 ± 9 ng kg/mg ml, 210 ± 70 ng h kg/mg ml and 2.6 ± 0.9 ng kg/mg ml, respectively. For intramuscular administration, levels were about 5.5-fold, 9-fold and 22-fold higher. Based on pharmacokinetic data, the efficacy of oral cyclosporine treatment (without any other immunosuppressant) was evaluated in life-supporting cynomolgus monkey kidney allotransplantation. Rejection-free kidney allograft survival could be achieved using oral cyclosporine monotherapy with average 24-h trough concentrations above 100 ng/ml during maintenance treatment. Typically, daily oral doses of 100 mg/kg–150 mg/kg during the first two weeks post-transplantation, followed by daily 30 mg/kg–100 mg/kg dose levels during subsequent maintenance can result in long-term allograft survival, with 24-h average trough levels in individual animals during maintenance between 110 ng/ml and 700 ng/ml. Received: 1 October 1997 Revised: 20 April 2001 Accepted: 7 June 2001  相似文献   

9.
The relative bioavailability of enteric-coated sodium fluoride (NaF) tablets (10 mg F) has been assessed following administration with a standard calcium-rich breakfast or calcium-poor lunch, and 2 h before or simultaneously with antacid administration (2.4 g aluminum-magnesium hydroxide), versus intake on an empty stomach. Twelve volunteers were studied 3 times according to an open, three-way crossover design over a 24 h period at weekly intervals. Meals were found to decrease the peak serum concentration of NaF from 122 μg/L during fasting (after baseline subtraction) to 71 and 88 μg/L with breakfast and lunch respectively, and to slow its absorption rate with Tmax increasing from 3.3 to 7.3 and 11.2 hours, without altering its bioavailability. Antacid impaired the bioavailability of NaF by 80% when administered simultaneously, with AUC decreasing from 987 to 155 μg.h/ L, but had no significant effect when taken 2 h before NaF. In conclusion, the enteric-coated NaF tablets used in this study can be administered with food or after a 2-hour delay following antacid administration, but should not be taken simultaneously with antacid.  相似文献   

10.
To compare the effectiveness of propofol given intravenously and rectally, ten piglets received propofol intravenously. On the next day, the same piglets and five other piglets were given suppositories containing propofol. Serial blood samples were collected for the analysis of propofol plasma concentration. The time course of the total plasma drug concentration was fitted into a bi-exponential function using a least square fitting regression computer programme. The volume of distribution was 2.5-2.8 l.kg-1, mean elimination half-life, 23.9 min and mean clearance 0.08 l.kg-1.min-1. The mean bioavailability by the rectal route was low. In contrast to the intravenously administered propofol, none of the piglets slept when given propofol rectally, reflecting the extremely low plasma propofol concentration. In veterinary medicine, propofol would seem to be clinically valuable for inducing intravenous anaesthesia, but would be ineffective when given rectally. The findings indicate that with the dosage forms used here, propofol would be clinically ineffective if given rectally to human infants and children.  相似文献   

11.
The effects of 5, 10, and 20% dietary xylitol supplementations on the resorption of bone were studied. The resorption was measured by the urinary excretion of [3H] radioactivity from [3H]tetracycline-prelabeled rats. The 10 and 20% oral xylitol administrations caused a significant decrease in the excretion of [3H] as compared with the control group with no xylitol supplementation. The effect was detected as early as 2 days after the beginning of xylitol-feeding and was maintained throughout the experimental period of 31 days. The retarding effect on bone resorption was about 25% in the 10% xylitol group, about 40% in the 20% xylitol group, and undetectable in the 5% xylitol group. The amount of preserved [3H] radioactivity in the tibiae of the 10 and 20% xylitol groups after the experiment clearly exceeded the valties of the control group. The mechanism of the retarded bone resorption caused by dietary xylitol still remains obscure, but an increased absorption of calcium may be involved. In conclusion, dietary xylitol supplementation in rats seems to retard the bone resorption in a dose-dependent way. The effect is achieved rapidly and is maintained at least over a period of 1 month xylitol feeding.  相似文献   

12.
目的:观察联合维生素D和第三代二膦酸盐对糖皮质激素长期应用所造成的骨量丢失肾炎患者的疗效。方法:15例来自本院经定量CT(QCT)诊断为糖皮质激素性骨质疏松和骨量减少病情稳定肾炎患者,服用钙尔奇1片/d和福善美70mg/周,观察入选时及治疗6月后临床症状和空腹血钙、磷、甲状旁腺激素、碱性磷酸酶、24h尿钙、磷和定量CT腰椎骨密度值变化。结果:疼痛症状改善总有效率(显效加有效)为53.3%。治疗6个月前后血钙、磷、甲状旁腺激素、碱性磷酸酶、24h尿钙、磷变化,无统计学意义(P〉0.05),腰椎骨密度差值为(11.8±5.3)mg/cm^3,经检验有统计学意义(P〈0.01)。结论:维生素D联合二膦酸盐能有效改善糖皮质激素长期应用所造成的骨量丢失,增加骨密度,改善疼痛,有利于最大程度的预防骨质疏松骨折,但是否优于传统单纯钙和维生素D治疗有待进一步对照研究。  相似文献   

13.
BackgroundThe aim of the study was to evaluate the effects of the using bisphosphonate, vitamin D, and a combination of bisphosphonate and vitamin D on fracture healing, by comparison of radiological and histological findings of the study groups and a control group.MethodsA total of 24 rats were randomly divided into 4 groups. A mid-third fracture was created in the femur of all rats. Saline was administered to Group A, bisphosphonate (Alendronate) to Group B, bisphosphonate (Alendronate) + vitamin D (Calcitriol) to Group C and vitamin D (Calcitriol) to Group D. All preparations were administered orally for 28 days.ResultsNo statistically significant difference was determined between the groups in respect of the effect on fracture healing according to radiological findings. The histological findings of fracture healing showed Groups B and C to be significantly more advanced than Group A (p = 0.017, p = 0.009). However no significant difference was found in Group D comparison with Group A (p = 0.224).ConclusionAccording to the histological findings, advanced fracture healing was seen in the groups administered with bisphosphonate or combined bisphosphonate and vitamin D compared to the use of vitamin D alone and the control group. It was concluded that bisphosphonate treatment combined with vitamin D can be used safely without any negative effect on fracture healing.  相似文献   

14.
目的 探讨年龄因素对患者硬膜外注射左旋布比卡因药效学和药代动力学的影响.方法 择期拟行下肢手术患者45例,年龄30~72岁,体重52~83 ks,ASA Ⅰ或Ⅱ级,按不同年龄分为3组:Ⅰ组(≤45岁)、Ⅱ组(46~64岁)和Ⅲ组(>64岁),每组15例,均采用腰段硬膜外麻醉,左旋布比卡因(7.5 mg/ml)用量1.8 mg/kg(含肾上腺素5 μg/ml).经L1,2硬膜外穿刺成功后,注射试验量0.5%左旋布比卡因3 ml,3 min后注射剩余量0.75%左旋布比卡因.硬膜外注药后记录感觉和运动阻滞效果及不良反应的发生情况;每组随机选择9例,于注药后即刻、注药后10、20、30、45、60、90、120、180、240、360、480、840、和1 440 min时采用高效液相色谱法测定血浆左旋布比卡因浓度,绘制血浆左旋布比卡因浓度-时间曲线,计算3组药代动力学参数.结果 与Ⅰ组比较,Ⅲ组最高感觉阻滞平面高,感觉和运动阻滞维持时间长,(P<0.05);各组麻醉效果优良率均达100%;各组左旋布比卡因的血浆药物浓度-时间曲线均符合二房室开放模型;硬膜外注药后1 440 min时Ⅱ组和Ⅲ组左旋布比卡因血药浓度高于Ⅰ组(P<0.05);Ⅱ组和Ⅲ组左旋布比卡因消除半衰期明显长于Ⅰ组,Ⅲ组明显长于Ⅱ组(P<0.05).结论 不同年龄患者硬膜外注射0.75%左旋布比卡因1.8 mg/kg安全有效;随年龄增加,感觉阻滞平面升高、感觉和运动阻滞恢复时间延长,药物代谢明显减慢.  相似文献   

15.
口服他克莫司血药浓度-时间曲线下面积   总被引:3,自引:0,他引:3  
目的 探讨口服他克莫司 (Tacrolimus ,FK5 0 6 )的药代动力学规律 ,寻求临床上准确反映早期药物浓度时间曲线下面积 (AUC)的监测方法。 方法  16例肾移植受者首剂口服 0 .0 75mg/kgFK5 0 6后 ,采用ELISA法测定服药后 0 .5、1.0、1.5、2 .0、3.0、5 .0、8.0、12 .0h时间点血药浓度 ,采用 3p87药代动力学计算程序将测得的FK5 0 6浓度自动拟合计算出AUC ,并分别将各时间点血药浓度与AUC进行相关性检验 ,计算相关系数。 结果 AUC变化范围为 4 4 .4 0~ 15 8.0 1μg·h-1·L-1,平均 ( 92 .2 3± 34.97) μg·h-1·L-1,个体间AUC可相差 4倍 ;血药谷浓度Cmin与AUC之间的相关性有显著差异 (P <0 .0 0 1,rmin=0 .6 5 0 )。 结论 首剂口服同一剂量FK5 0 6后 ,个体间药物浓度时间曲线下面积差异很大。Cmin能准确反映首剂口服FK5 0 6后的AUC ,临床上可通过监测Cmin达到FK5 0 6早期剂量的个体化  相似文献   

16.
The effects of single or repeated doses of desmopressin on blood loss were examined in uncomplicated cardiac surgery, while assessing the potential for thrombogenic side effects. Seventy patients undergoing elective coronary artery bypass grafting (CABG) were studied. Patients were randomized into three blinded groups: Group I received DDAVP (0.3 micrograms/kg), IV, after cardiopulmonary bypass (CPB) and 12 hours later in the Intensive Care Unit (ICU); Group II, DDAVP (0.3 micrograms/kg), IV, after termination of CPB and saline (placebo) 12 hours later in the ICU; Group III, saline (placebo) IV after CPB and 12 hours later in the ICU. Blood loss and bleeding time decreased for Group I at 24 hours (P < 0.04) when compared to Group III; however, blood product replacement, as well as intraoperative and total blood loss at 36 hours, were not different among treatment and control groups. There were four myocardial infarctions recorded in Group I, two in Group II, and one in Group III. These differences were not found to be statistically significant. It is concluded that in routine CABG the prophylactic use of single or repeat dose DDAVP does not effectively decrease blood loss or blood product replacement.  相似文献   

17.
18.
BACKGROUND: Symptomatic hypocalcemia remains the main postoperative complication after total thyroidectomy. The aim of the present study was to evaluate the role of oral supplementation of calcitriol and calcium salts in preventing severe postoperative hypocalcemia after total thyroidectomy. METHODS: A consecutive series of patients undergoing total thyroidectomy followed by administration of 500 mg of calcium salts 3 times per day were randomized to 3 different postoperative medical treatments: in group A, .5 microg of calcitriol twice per day was administered to 104 patients; in group B, 1 mmicrog of calcitriol twice per day was administered to 111 patients; and in group C, 202 patients did not receive calcitriol. RESULTS: The rate of postoperative tetany in group A was 2.9%, in group B was 0%, and in group C was 7.4% (P=.03) and the rate of paresthesias was 28.8%, 17.1%, and 22.3%, respectively (P=.19). At discontinuation of calcitriol/calcium salts treatment, intact parathyroid hormone levels did not significantly differ from the preoperative levels. Receiver operating characteristic (ROC) curve analysis showed that the area under the curve for serum concentration of calcium in predicting postoperative tetany was .749, .858 and .862 on the first, second, and third postoperative day, respectively. The best cut-off value of calcemia for prediction tetany was 7.5 mg/dL, and the rate of severe hypocalcemia on the third postoperative day was 23.1% in group A, 9.9% in group B, and 27.2% in group C (P=.001). CONCLUSIONS: Oral administration of 1 microg of calcitriol twice per day and 500 mg of calcium salts 3 times per day after total thyroidectomy significantly decreases the risk of severe postoperative hypocalcemia.  相似文献   

19.
Objective To evaluate the efficacy of two prophylactic schemes for prostate biopsy using a single dose of oral levofloxacin given either before, or immediately after transrectal ultrasound-guided prostate biopsy. Materials and methods A total of 300 men formed two groups of 150 patients each: the first group received one dose of 500 mg of levofloxacin 30 min to an hour before, and the second group the same antibiotic immediately after prostate biopsy. No pre-biopsy enema was used. Side effects after prostate biopsy were recorded, and the two groups were compared. Results Only one patient from the first group developed a urinary tract infection after biopsy. A mean number of more than 10 cores per patient were taken. Haematuria was the most common complaint, followed by haemospermia. Haematuria and rectal bleeding were more common in patients where more than 8 cores were taken from the prostate (P = 0.005 and P = 0.017, respectively). Prostate cancer was detected in 34.3% of patients in total. Conclusion The use of a single dose of 500 mg levofloxacin given immediately after prostate biopsy proved to be quite effective for the prevention of infectious complications, even in the setting of an extensive biopsy protocol.  相似文献   

20.
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