氨氯地平及硝苯地平控释片引起老年患者严重水肿

1例82岁男性患者,因患冠心病、高血压多年住院治疗。给予氨氯地平5mg,1次/d口服。服药1周后出现下肢水肿,15d后发展为全身水肿,检查见胸腔、心包积液。怀疑患者心功能不全,氨氯地平加量至5mg,2次/d口服,次日水肿急剧加重。停用氨氯地平,改用硝苯地平控释片30mg,1次/d,呋塞米20mg,2次/d口服,2d后水肿逐渐减轻,1个月后水肿完全消退出院。5个月后因血压高(180～170/120～100mmHg)再次入院。硝苯地平控释片加量为30mg,2次/d,20d后见眼睑、下肢水肿,超声心动图(UCG)检查示心包少量积液,硝苯地平控释片减量为30mg,1次/d,加用呋塞米20mg,2次/d口服,3d后水肿逐渐消退,3周后痊愈出院。     

硝苯地平对慢性阻塞性肺病患者茶碱药物动力学的影响

 目的：研究慢性阻塞性肺病（COPD）患者合用硝苯地平前后茶碱稳态血药浓度及药物动力学的变化。方法：高效液相色谱（HPLC）法测定9名COPD患者po茶碱片（200 mg,tid）5 d后及加服硝苯地平（10 mg，tid)5 d后茶碱血药浓度，以PKBP-N₁计算机程序拟合药物动力学参数。结果：COPD患者合用硝苯地平5 d后，茶城稳态平均血药浓度下降1.77士2.04 mg/L，c_max和AUC_0～8均较用硝苯地平前降低，分别为12.3士6.5和9.9士4.9 mg/L，82.4士52.1和62.5士38.8（mg?h)/L(P<0.05)。其它药物动力学参数无明显改变（P>0.05)。结论：COPD患者合并使用硝苯地平，无需改变氨茶碱的治疗剂量，两药可以合用。     

The effect of food on the pharmacokinetics of nifedipine in two slow release formulations: pronounced lag-time after a high fat breakfast

AIMS: The aim of this study was to investigate the effect of concomitant food intake on the bioavailability of two nifedipine containing modified release dosage forms for once daily administration. The clinical study was performed to investigate the in vivo relevance of pH-dependent differences in the in vitro release properties of the two dosage forms. METHODS: This was a randomized, open, 4-way crossover study in 24 healthy, male subjects. Following an overnight fast of 12 h single doses of Adalat OROS or Slofedipine XL were administered either in the fasted state or immediately after a high fat American breakfast. Nifedipine plasma concentrations in samples obtained until 48 h after drug administration were determined using a validated LC-MS/MS method. Calculation of pharmacokinetic parameters was conducted model-independently. The two dosage forms as well as the two administration conditions were compared by calculating point estimates and 90% confidence intervals for the relevant pharmacokinetic parameters. In vitro dissolution tests were performed using a paddle apparatus 3 acc. USP, a pharmacopoeial dissolution system consisting of reciprocating cylinders in flat-bottomed glass vessels, with various buffer systems covering the entire physiological pH-range of the gastrointestinal tract. RESULTS: After fasted administration the extent of bioavailability of nifedipine as characterized by AUC(0,infinity) was slightly lower for Slofedipine XL compared with Adalat OROS with a point estimate of 82.3% primarily resulting from pronounced differences in nifedipine concentrations during the first 15 h after administration. Accordingly, maximum plasma concentrations were lower after administration of Slofedipine XL compared with Adalat OROS (point estimate: 84.3%). Under fed conditions the differences in bioavailability between the two products as characterized by the pharmacokinetic parameters AUC(0,tn) and Cmax were greater than after fasting conditions with point estimates of 69.6% and 81.0%, respectively. However, most striking was a pronounced delay in nifedipine absorption observed under fed conditions after administration of Slofedipine XL which resulted in lag-times of more than 15 h in 15 out of 24 subjects. Owing to this lag-time under fed conditions the relative bioavailability of nifedipine from Slofedipine XL compared with Adalat OROS was only 28% over the intended dosing interval of 24 h. CONCLUSIONS: In this study a dosage form-dependent food interaction was observed which, under fed conditions, resulted in pronounced differences in the relative bioavailability of nifedipine between Slofedipine XL and Adalat OROS over the intended dosing interval of 24 h. The delay in nifedipine absorption when Slofedipine XL is administered after a high-fat breakfast may be explained by the formulation properties. Slofedipine XL is an erosive tablet with an acid resistant coating whereas Adalat OROS is designed with an osmotic push-pull system. Under fed conditions drug from the single unit enteric coated dosage form exhibits a delayed absorption probably due to an extensively prolonged gastric residence time which does not allow drug release, on the other hand the osmotically driven push-pull system is not sensitive to concomitant food intake. The observed phenomenon might be of therapeutic relevance. For example a change from taking Slofedipine XL in the fed to the fasted state might result in increased systemic concentrations of nifedipine.     

硝苯地平与银杏黄酮的体外代谢性相互作用

 目的通过体外代谢获得药物相互作用的有关数据,以预测临床联合用药时发生代谢性药物相互作用的可能性。方法以HPLC测定孵育液中剩余银杏黄酮的浓度,计算共孵育药物硝苯地平对银杏黄酮3个苷元的IC₅₀值和K_i值;以HPLC测定孵育液中硝苯地平的浓度,计算其代谢抑制率。结果硝苯地平与银杏黄酮进行体外共孵育时,代谢互受影响。结论两药合用时宜慎重。     

吡那地尔和硝苯地平对内皮素缩血管作用的影响

目的：观察吡那地尔（Ｐｉｎ）和硝苯地平（Ｎｉｆ）对内皮素－１（ＥＴ－１）缩血管作用的影响并探讨其作用机理。方法：以ＥＴ－１在含Ｃａ２＋和不含Ｃａ２＋Ｋ－Ｈ液中预收缩离体大鼠主动脉环，比较Ｐｉｎ和Ｎｉｆ累积给药的扩血管效应。结果：在含Ｃａ２＋Ｋ－Ｈ液中，Ｐｉｎ和Ｎｉｆ均可浓度依赖性地对抗ＥＴ－１１ｎｍｏｌ·Ｌ－１的缩血管作用，ＥＣ５０分别为０．５０和０．１３μｍｏｌ·Ｌ－１。ＥＣ９５则分别为３２和３６９６μｍｏｌ·Ｌ－１。Ｐｉｎ１００μｍｏｌ·Ｌ－１可完全抑制ＥＴ－１诱发的血管收缩，相同浓度的Ｎｉｆ仅具部分抑制作用。在无Ｃａ２＋Ｋ－Ｈ液中，Ｐｉｎ１～５０μｍｏｌ·Ｌ－１亦可浓度依赖地对抗ＥＴ－１１ｎｍｏｌ·Ｌ－１的缩血管作用，其ＥＣ５０为３．８９μｍｏｌ·Ｌ－１，扩血管作用较在含Ｃａ２＋Ｋ－Ｈ液中减弱８倍。同样条件下，Ｎｉｆ未显示相应的作用。结论：ＥＴ－１的缩血管作用既与其阻断ＡＴＰ敏感性钾通道所中介的细胞外钙内流有关又涉及其激动相应受体所介导的细胞内钙释放。Ｐｉｎ和Ｎｉｆ均可对抗ＥＴ－１的缩血管作用，Ｐｉｎ的作用机制涉及其阻断电压依赖性钙通道和抑制细胞内钙释放两方面，而Ｎｉｆ的作用仅与其选择性阻断电压依赖性?     

The effect of nifedipine on monocrotaline-induced pulmonary hypertension in rats

Effective drug therapy for pulmonary hypertension has not yet been developed. This study was designed to estimate the long-term hemodynamic and histopathological effects of nifedipine on severe pulmonary hypertension using animal models. Injection of one dose of monocrotaline produced subacute pulmonary hypertension in 7 week old Sprague-Dawley rats. Nifedipine (10 mg/kg) was administered intraperitoneally every day. For 5 weeks, bodyweight and hemodynamic parameters were measured, and right ventricle (RV) and left ventricle with septum (LV + S) were weighed separately. Medial thickness of the small pulmonary arterial wall was calculated by Suwa's method. Compared with the control group, the increase in right ventricular systolic pressure, total pulmonary resistance index, weight ratio of RV/(LV + S) and medial hypertrophy in the nifedipine-treated rats were significantly limited without causing systemic hypotension. These results suggest that treatment with nifedipine may also be effective in attenuation of pulmonary hypertension when applied to humans.     

高血压左室肥厚大鼠血管内皮的去留对NE和Ach反应的研究

间硝地平(m-Nif)和硝苯地平(Nif)在预防和逆转肾型高血压大鼠左室肥厚(LVH)的同时可通过影响血管平滑肌功能和血管内皮功能来降低血管对NE的反应性.抑制NE收缩反应:LVH组ED_50在内皮完整和去内皮时分别为101±39nmol·L~(-1),360±72nmol·L~(-1),NE-比率为1.80,各药物组的ED_(50)均增大,NE-比率降低.LVH大鼠血管对Ach的依内皮性舒张反应降低,m-Nif和Nif对Ach依内皮舒张反应没有明显影响.     

Antihypertensive drugs and the risk of idiopathic aplastic anaemia

AIMS: A recent report has raised concern that nifedipine may be associated with an increased risk of aplastic anaemia. This large population-based study evaluated the risk of idiopathic aplastic anaemia in users of calcium channel blockers compared with that of other antihypertensive drugs. METHODS: The study was based on information derived from the General Practice Research Database. We conducted a follow-up study with a nested case-control analysis of 322 448 subjects who received antihypertensive drugs. Cases were people who had a first-time diagnosis of aplastic anaemia during January 1, 1988 through September 30, 1997. The risk estimate of aplastic anaemia was calculated for all antihypertensive drugs. For the nested case-control analysis, six controls were matched to each case on age, sex and general practice attended. Odds ratios compared the risk of idiopathic aplastic anaemia for all antihypertensive drugs relative to nonusers. RESULTS: There were 13 cases of newly diagnosed idiopathic aplastic anaemia. The estimated risk of aplastic anaemia per 100 000 users was 0.8 (95% CI 0.1, 4.7) for calcium channel blockers, 1.4 (95% CI 0.5, 4.1) for beta-adrenoceptor blockers, 2.3 (95% CI 0.6, 8.6) for angiotension-converting enzyme (ACE) inhibitors and 5.9 (95% CI 1.6, 21.5) for users of other antihypertensive drugs. In the case-control analysis of 13 cases and 77 controls, the odds ratio was 0.3 (95% CI 0.02, 3.3) for calcium channel blockers, 0.5 (95% CI 0.1, 2.5) for beta-adrenoceptor blockers, 0.7 (95% CI 0.1, 5.6) for ACE inhibitors, 1.2 (95% CI 0.1, 11.8) for users of other antihypertensive drugs and 0.7 (95% CI 0.1, 7.2) for users of multiple drugs with a calcium channel blocker compared with nonusers. CONCLUSIONS: The present study suggests that the use of calcium channel blockers is not associated with an increased risk of aplastic anaemia.     

气质联用（GC／MS）法测定血浆中硝苯地平的浓度

本文建立了气相色谱－质谱联用（ＧＣ－ＭＳ）法测定人血浆中硝苯地平浓度的方法。以安定为内标，经气相色谱分离后（程度升温），质谱单离子检测（ＳＩＭ）Ｍ／Ｚ２８４。结果表明：该方法选择性好、灵敏度高，在１￣２００ｎｇ／ｍｌ浓度范围内线性较好，回收率及精密度均能符合要求。     

病毒唑联合硝苯吡啶治疗病毒性肠炎疗效观察

用病毒唑和硝苯吡啶联合治疗婴幼儿病毒性肠炎１００例，同时设对照组ｌ００例给予一般治疗。结果显示治疗组平均止泻时间３．１±０．８４天，对照组平均止泻时间４．５７±１．１７天，两组差异有显著意义（χ２＝５．５９，Ｐ＜０．０１）。