Effect of pregnancy on the pharmacokinetics of metformin.

AIMS: To determine the effects of pregnancy on metformin pharmacokinetics. METHODS: Seven women with Type 2 diabetes mellitus taking metformin throughout pregnancy were studied on two occasions, once at 28-36 weeks gestation and once at least 8 weeks postpartum. Serum metformin concentrations were determined across a dosing interval using high-performance liquid chromatography. The areas under the serum concentration-time curve from 0 to 4 h post-dose (AUC0-4) and 0 to 8 h post-dose (AUC0-8) where possible, were compared in the pregnant and non-pregnant state. RESULTS: Metformin concentrations were lower in pregnancy in six subjects, with a mean (95% CI) AUC0-4 that was 69% (53.6, 84.8) of the postpartum value. The AUC0-4 of one subject was higher in pregnancy at 142% of the postpartum value. Overall, the mean (95% CI) AUC0-4 during pregnancy for all seven subjects was 80% (51.3, 107.8) of the postpartum value (P = 0.053, two-tailed t-test; P = 0.027, one-tailed t-test). CONCLUSION: These results are consistent with our hypothesis that the clearance of metformin increases in pregnancy as a result of enhanced renal elimination. A larger study is required to establish whether metformin dose adjustments are required in late pregnancy to maintain therapeutic effect.     

Flutamide-metformin plus an oral contraceptive (OC) for young women with polycystic ovary syndrome: switch from third- to fourth-generation OC reduces body adiposity

BACKGROUND: Low-dose flutamide-metformin has been developed as a background therapy for non-obese adolescents and young women with hyperinsulinaemic hyperandrogenism, a variant of polycystic ovary syndrome (PCOS). We verified whether the lipolytic efficacy of flutamide-metformin in women with PCOS is enhanced by giving an oral contraceptive (OC) co-therapy that contains drospirenone, instead of gestodene, as progestin. METHODS: An open-labelled study was carried out in which non-obese women with PCOS (n = 29; age approximately 20 years), who had been on a combination of flutamide (62.5 mg/day), metformin (850 mg/day) and ethinylestradiol-gestodene for 8-15 months, were randomized for replacement of the gestodene OC by a drospirenone OC. Assessments of endocrine-metabolic state and body composition (by dual-energy X-ray absorptiometry) were performed at randomization and after 6 months. RESULTS: The switch to drospirenone OC was accompanied by a reduction of total and abdominal fat (mean -0.8 and -0.5 kg) and by an increment of lean body mass (+0.6 kg; all P < 0.01), so that body adiposity was strikingly reduced without changing body weight. CONCLUSION: In non-obese women with PCOS, low-dose flutamide-metformin reduces total and abdominal fat excess more effectively if contraceptive co-therapy contains drospirenone, instead of gestodene, as progestin.     

Comparison of the effects of acarbose and metformin use on ovulation rates in clomiphene citrate-resistant polycystic ovary syndrome

BACKGROUND: The aim of this study was to evaluate the effects of metformin and acarbose on insulin resistance, hormone profiles and ovulation rates in patients with clomiphene citrate-resistant polycystic ovary syndrome (PCOS). METHODS: Thirty clomiphene citrate-resistant patients were selected randomly and divided into two groups. Group I was treated with 100 mg/day clomiphene citrate and 300 mg/day acarbose 100 mg/day orally, for 3 months. Group II was treated with clomiphene citrate 100 mg/day and metformin 1700 mg/day orally, for 3 months. Serum fasting insulin and glucose, FSH, LH, estradiol, progesterone, prolactin and total testosterone levels plus body mass index (BMI) were measured before and after treatment. Follicle growth was followed by transvaginal ultrasonography. RESULTS: LH:FSH ratio and total testosterone concentrations decreased (P<0.05) and ovulation rates increased in both groups. Reduction in weight and BMI was only significant in the acarbose group. CONCLUSIONS: Both treatment modalities were effective in the treatment of insulin resistance and improving ovulation rates. Increase in the number of eumenorrhoeic and normoinsulinaemic cases and decrease in the number of insulin-resistant cases were significant in both groups (P<0.05). Ovulation rate was greater in the metformin group in the second month of therapy (P<0.05). Acarbose was found to be a safe and effective agent that could be used in cases with clomiphene-resistant PCOS.     

Metformin during pregnancy reduces insulin, insulin resistance, insulin secretion, weight, testosterone and development of gestational diabetes: prospective longitudinal assessment of women with polycystic ovary syndrome from preconception throughout pregnancy

BACKGROUND: In a prospective observational study of 42 pregnancies in 39 Caucasian women (age 30 +/- 4 years) with polycystic ovary syndrome (PCOS), we examined effects of metformin on maternal insulin, insulin resistance (IR), insulin secretion (IS), weight gain, development of gestational diabetes (GD), testosterone and plasminogen activator inhibitor activity. We assessed the hypothesis that diet-metformin (MET) lessens the physiological gestational increase in IR and reduces gestational weight gain, thus reducing GD. METHODS: Preconception, in an out-patient clinical research centre, MET 1.5 (eight pregnancies) to 2.55 g/day (34 pregnancies) was started. Women with body mass index <25 or >or=25 kg/m(2) were given a 2000 or 1500 calorie/day, high-protein (26% of calories), low-carbohydrate (44%) diet. Calorie restrictions were dropped after conception. RESULTS: On MET, GD developed in three out of 42 pregnancies (7.1%). Median entry weight (94.5 kg) fell to 82.7 on MET at the last preconception visit (P = 0.0001), fell further to 81.6 during the first trimester, was 83.6 in the second trimester, and 89.1 kg in the third trimester. Median weight gain during pregnancy was 3.5 kg. The median percentage reduction in serum insulin was 40% on MET at the last preconception visit; insulin did not increase in the first or second trimesters (P > 0.05), and rose 10% in the third trimester. The median percentage reduction in HOMA IR was 46% on MET at the last preconception visit; IR did not increase (P > 0.05) in the first, second or third trimesters. HOMA insulin secretion fell 45% on MET at the last preconception visit, did not increase in the first trimester, rose 24% in the second trimester, and rose 109% in the third trimester. Testosterone fell 30% on MET at the last preconception visit (P = 0.01) and then rose 74, 61 and 95% during trimesters 1, 2 and 3; median testosterone during the third trimester did not differ from pre-treatment levels. CONCLUSIONS: By reducing preconception weight, insulin, IR, insulin secretion and testosterone, and by maintaining these insulin-sensitizing effects throughout pregnancy, MET-diet reduces the likelihood of developing GD, and prevents androgen excess for the fetus.     

Vitamin B12 Supplementation in Diabetic Neuropathy: A 1-Year,Randomized, Double-Blind,Placebo-Controlled Trial

Aim: To investigate the effect of normalizing vitamin B12 (B12) levels with oral B12 (methylcobalamin) 1000 μg/day for one year in patients with diabetic neuropathy (DN). Patients and methods: In this prospective, double-blind, placebo-controlled trial, 90 patients with type 2 diabetes on metformin for at least four years and both peripheral and autonomic DN were randomized to an active treatment group (n = 44) receiving B12 and a control group (n = 46) receiving a placebo. All patients had B12 levels less than 400 pmol/L. Subjects underwent measurements of sural nerve conduction velocity (SNCV), sural nerve action potential (amplitude) (SNAP), and vibration perception threshold (VPT), and they performed cardiovascular autonomic reflex tests (CARTs: mean circular resultant (MCR), Valsalva test, postural index, and orthostatic hypotension). Sudomotor function was assessed with the SUDOSCAN that measures electrochemical skin conductance in hands and feet (ESCH and ESCF, respectively). We also used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE, respectively) and questionnaires to evaluate quality of life (QoL) and level of pain (pain score). Results: B12 levels increased from 232.0 ± 71.8 at baseline to 776.7 ± 242.3 pmol/L at follow-up, p < 0.0001, in the active group but not in the control group. VPT, MNSIQ, QoL, pain score, SNCV, SNAP, and ESCF significantly improved in the active group (p < 0.001, p = 0.002, p < 0.0001, p < 0.000, p < 0.0001, p < 0.0001, and p = 0.014, respectively), whereas CARTS and MNSIE improved but not significantly. MCR, MNSIQ, SNCV, SNAP, and pain score significantly deteriorated in the control group (p = 0.025, p = 0.017, p = 0.045, p < 0.0001, and p < 0.0001, respectively). Conclusions: The treatment of patients with DN with 1 mg of oral methylcobalamin for twelve months increased plasma B12 levels and improved all neurophysiological parameters, sudomotor function, pain score, and QoL, but it did not improve CARTS and MNSIE.     

盐酸二甲双胍缓释片在健康受试者餐后条件下的生物等效性研究

评价盐酸二甲双胍缓释片受试制剂和参比制剂在健康受试者餐后单次给药条件下的生物等效性和安全性。试验采用单中心、随机、开放、单剂量、两周期、两序列、双交叉设计,32例健康受试者在餐后状态下单次服用受试制剂或参比制剂0.5 g,在给药前(0 h)至给药后1、3、4、4.5、5、5.5、6、7、8、9、10、12、15、24、36和48 h采集静脉血4 mL,检测血浆样本中二甲双胍的浓度,用Win Nonlin 7.0软件计算药代动力学参数,当受试制剂与参比制剂的c_max、AUC_0-t、AUC_0-∞几何均值比的90%置信区间均在80.00%～125.00%等效区间内,证明两制剂生物等效。有1例受试者因不良事件脱落。受试制剂和参比制剂的主要药代动力学参数：c_max为(0.68±0.14)和(0.65±0.11) mg/L,AUC_0-t为(7.33±1.65)和(7.00±1.89) h·mg/L,AUC_0-∞为(7.39±1.67)和(7.06±1.91) h·mg...     

瑞格列奈联合NPH睡前注射治疗2型糖尿病的临床观察

目的：比较瑞格列奈(Repaglinide)联合生物合成中效人胰岛素(NPH)睡前注射治疗和单用二甲双服治疗，对磺脲类药物(SU)控制不佳的2型糖尿病(T2DM)患者的疗效、安全性及对胰岛P细胞功能的影响。方法：观察组用瑞格列奈联合NPH睡前注射治疗，对照组用二甲双服治疗，疗程均为12周，观察治疗前后的空腹血糖(FBG)、餐后2h血糖(P2BG)、糖化血红蛋白(HbA1c)、体重指数(BMI)、空腹C肽(FCP)及餐后2hC肽(P2CP)分泌水平。结果：12周后，观察组的FBG，P2BG，HbA1c明显下降(均P＜0．01)，FCP明显升高(P＜0．05)，P2CP变化无统计学意义。同对照组相比FBG，P2BG，HbA1c，FCP等指标的改善有较显著差异(均P＜0．01)。对照组治疗前后比较，FBG，BMI下降明显(均P＜0．05)，P2BG，HbA1c，FCP，P2CP变化无统计学意义。结论：瑞格列奈联合NPH治疗方案适合于T2DM对SU疗效不佳者，且对胰岛β细胞功能有改善，安全性及耐受性良好。     

盐酸二甲双胍薄膜衣片剂质量评价

目的：选择对临床作用有影响的药剂学指标，依照《中国药典》规定对天津地区市售6个厂家12个批号的盐酸二甲双胍薄膜衣片剂进行质量评价。方法：以紫外分光光度法测定含量，用转篮法测定溶出度，并就溶出和含量进行分析比较。结果：6厂家产品的溶出度均达到《中国药典》规定的要求。结论：经检测被评价的6个厂家12个批号上市产品质量有差异，其中5个厂家11个批号的产品符合《中国药典》规定标准，1个厂家产品含量偏低。     

盐酸二甲双胍缓释片体外释放度研究

目的对盐酸二甲双胍缓释片体外释放度相关因素进行研究。方法对溶出介质、转速、测定波长及辅料等因素进行考察,确定盐酸二甲双胍缓释片体外释放度的测定方法,对测定方法进行回收试验,并对三批样品及参比制剂进行测定。结果采用转篮法,以1000ml水为溶出介质,转速为100rpm/min,采用UV法,测定波长为233nm,将溶出液稀释至1～12.5μg/ml进行测定。结论本释放度方法简单,快速,可用于盐酸二甲双胍缓释片体外释放度测定。