Physiological pharmacokinetics and pharmacodynamics of (+/-)-verapamil in female rats

Tissue distribution and pharmacodynamics of verapamil were evaluated during steady state intravenous (i.v.) infusion and after single dose intraperitoneal (i.p.) drug administration to female Sprague-Dawley rats. In one group of rats, verapamil was infused to a steady state concentration at which time animals were killed. Verapamil-induced decreases in mean arterial pressure (MAP) were monitored during infusion and correlated with concomitantly obtained plasma verapamil concentrations. Tissue (lung, liver, renal medulla, renal cortex, cardiac muscle, skeletal muscle, perirenal fat, brain stem, cerebral cortex, and cerebellum) and plasma samples were obtained immediately after animals were killed and verapamil and norverapamil concentrations determined. Another group of rats, after receiving i.p. verapamil, were killed at 1, 3, 5, 19, and 24 h. Elimination from each tissue evaluated was described by a first order process. Elimination half-life of verapamil was similar among plasma and tissues evaluated (1.5 to 2.2 h). The per cent verapamil not bound to plasma proteins was concentration-independent and similar between rats receiving i.p. (mean +/- S.D.) (2.28 +/- 0.72 per cent) and i.v. (2.08 +/- 0.03 per cent) verapamil. MAP and verapamil concentration in plasma (r = 0.75; p less than 0.01) and cardiac muscle (r = -0.82; p less than 0.01) were inversely correlated in a highly significant fashion during both i.v. and i.p. drug administrations. The tissue-to-plasma distribution ratio for verapamil and norverapamil was similar among animals receiving i.p. verapamil at all points of sampling, suggesting distribution equilibrium had been achieved. After steady state i.v. infusion, both verapamil and norverapamil tissue: plasma concentration ratios were greater than after i.p. administration. Higher tissue: plasma verapamil concentration ratios after i.v. administration than after i.p. administration suggest either only a pseudoequilibrium is attained after i.p. administration or that determinants of tissue distribution of racemic verapamil differ with different routes of drug administration. In these studies, MAP provided a reasonable pharmacodynamic marker for verapamil tissue and plasma concentrations.     

复方18甲基炔诺酮透皮控释传递系统的LNG人体药物动力学与药效学评价

复方18甲基炔诺酮/雌二醇透皮控释传递系统(LNG/E_2 TCDS)能同时恒速释放低剂量的LNG和E_2,在1周内维持一个平稳而有效的LNG血药浓度。药动学与药效学研究证明,该系统释放的LNG能达到血清LNG目标水平,产生有效的排卵抑制(6/6)。LNG/E_2 TCDS可望发展成为一种安全、有效、非侵入性的新型生育调节避孕制剂。     

肾上腺素对丁哌卡因肌间沟臂丛神经阻滞的药效学与药代动力学的影响

目的:了解肾上腺素对丁哌卡因肌间沟臂丛神经阻滞的药效学及药动学影响。方法:选择ASA Ⅰ～Ⅱ级肩部或上肢择期手术患者16例,随机分成两组,试验组与对照组各8例,分别用含或不含肾上腺素的0.75％丁哌卡因2mg/kg行肌间沟臂丛阻滞。对比观察两组的临床效果及药代动力学。结果:与对照组比较,试验组阻滞完善时间及镇痛时间延长(P<0.05或0.01)。试验组与对照组Cmax分别为0.8295±0.2893ug/ml和0.8898±0.2572ug/ml,Tmax分别为37.6018±8.3461分钟和29.3156±11.1991分钟(P>0.05)。药代动力学参数t1/2Ka及K_(21)两组间有显著性差异(P<0.05或0.01)。结论:肾上腺素能延长丁哌卡因的阻滞完善时间、镇痛维持时间及吸收半衰期,但对血药浓度无明显影响。     

青山抗癌注射液抑制小鼠肿瘤生长的实验研究

目的：研究青山抗癌注射液对动物移植性肿瘤生长的影响．方法：以小鼠移植性肉瘤S180和肝癌H22为模型，以顺铂(DDP)为阳性对照，生理盐水(阳)为阴性对照，观察青山抗癌注射液对肿瘤生长的影响。结果：青山抗癌注射液不同剂量组对小鼠移植性肉瘤S180和肝癌H22的生长均显示了明显的抑制作用，与NS对照组相比，P＜0.01，且呈现出量效关系．结论：青山抗癌注射液具有抑制肿瘤生长的作用.     

Effect of omeprazole on the anticoagulant activity and the pharmacokinetics of warfarin enantiomers in rats

The effect of the proton pump inhibitor omeprazole on the anticoagulation and the pharmacokinetics of warfarin enantiomers was studied in rats. Omeprazole given intraperitoneally in a daily dose of 0.67 mg/kg over 8 days had no significant effect on the absorption, distribution and the total serum clearance values of the S- and R-enantiomers of warfarin. Omeprazole did not affect the pre-treatment baseline blood coagulation and the in vitro rat serum protein binding of warfarin enantiomers. In vitro study with rat liver microsomes showed that omeprazole had an inhibitory effect on the hydroxylation of warfarin enantiomers. Results obtained from in vivo urinary excretion study revealed that omeprazole inhibited the formation clearance of both S- and R-form oxidative metabolites, but increased that of the overall reductive metabolites, and the renal clearance of S- and R-enantiomers, of warfarin. As a consequence, the total serum clearance values for warfarin enantiomers remained unchanged and the hypoprothrombinaemic response produced by warfarin was not affected.     

An open label trial of raclopride in acute schizophrenia. Confirmation of D2-dopamine receptor occupancy by PET

Raclopride, a highly selective D2-dopamine receptor antagonist, was administered in doses up to 4 mg b.i.d. to ten schizophrenic patients in an open label non-comparative study lasting 4 weeks. Safety, tolerability, potential antipsychotic effect, prolactin response and drug effect on plasma homovanillic acid were evaluated. Central D2-dopamine receptor occupancy was determined by positron emission tomography (PET). No major deviations were found in biochemical and physiological safety parameters. Raclopride was well tolerated. The mean BPRS score was reduced by 55% at endpoint. In the global evaluation seven patients were very much or much improved. Extrapyramidal side effects were recorded in four patients and disappeared after dose reduction or single doses of biperiden. An increase in plasma prolactin of short duration was observed in both sexes. A significant decrease of plasma HVA was obtained after 4 weeks of treatment. In two of the patients the central D2-dopamine receptors occupancy was measured using PET. The receptor occupancy was 68 and 72% which is the same as that found in patients treated with conventional neuroleptics.     

Pharmacodynamic relationship between PCSK9, alirocumab,and LDL-C lowering in the ODYSSEY CHOICE I trial

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Human variability in susceptibility How big, how often, for what responses to what agents?

This paper first reviews in plain language some basic concepts and methods for estimating inter-individual variability in susceptibility from human data. A scale is offered to allow different variability findings to be understood and compared. Then the accumulated results of different variability analyses, information on how much variability has been observed and how often, is summarized in the form of a series of box plots. Data are presented on pharmacodynamic variability for various non-cancer effects, variability in susceptibility to infectious organisms, and variability in susceptibility to carcinogenesis by genetically-acting agents.     

单硝酸异山梨酯药动学和药效学特点及机制探讨

目的：对单硝酸异山梨酯药动学和药效学作用特点及其机制等方面进行评价,为该类药物的开发利用提供理论参考。方法：收集有关该药的国内外近期资料加以综合归纳。结果：较为系统的阐明了该药作用及作用机制在目前国内外研究状况,并提出将来的研究动态。结论：单硝酸异山梨酯具有疗效肯定、用途广泛、毒副作用小等特点     

布比卡因白蛋白微球的制备及药理学研究

目的制备盐酸布比卡因人血清白蛋白微球(Bupi-HSA-MS),并对其体内药动学、药效学及生物相容性进行评价。方法采用高压电场法制备布比卡因人血清白蛋白微球,采用改良的反相高效液相色谱法测定体内布比卡因血药浓度,以家兔为实验对象,以针刺疼痛反应圈直径大小评价其麻醉效果。结果药动学实验结果表明,注射剂组血药浓度达峰值时间短,浓度高,药物驻留时间短。微球组峰值浓度显著低于注射剂组并长时间维持低浓度。微球组MRT较对照组明显延长(P<0.01)。微球组皮下给药最大麻醉圈直径明显小于注射剂对照组(P<0.01),而微球组局麻持续时间较对照组明显延长(P<0.01)。结论高压电场法是一种简单、易行的白蛋白微球制备新方法。Bupi-HSA-MS兔皮下给药,药物扩散少,局部麻醉作用持续时间长,是一种安全长效的局部麻醉止痛新方法。