升压药米多君应用进展

米多君 (midodrine)是一种新型肾上腺素α1受体激动药 ,口服后呈线性药动学特征 ,生物利用度高 ,安全性、耐受性好。国外广泛应用于治疗直立性低血压、晕厥、尿失禁、肝硬化腹水、体位性心动过速等疾病     

米多君治疗症状性直立性低血压和复发性反射性晕厥有效

症状性直立性低血压（SOH）和复发性反射性晕厥（RRS）是两种致残性疾病。米多君已经被用于这些疾病的治疗,但其对患者主要预后的影响仍然不明确。为此,来自加拿大的学者Ariel Izcovich等进行了一项系统回顾以评估SOH和RRS患者采用米多君治疗的疗效和安全性。     

老年直立性低血压患者的护理观察

目的探讨对直立性低血压患者的护理干预效果。方法对23例直立性低血压患者采取护理干预。结果护理干预后,直立性低血压患者症状得到改善。结论护理干预可提高直立性低血压患者的生活质量。     

参附注射液联合米多君治疗血液透析性低血压的疗效观察

目的观察中药参附注射液联合小剂量米多君治疗血液透析性低血压的临床疗效。方法选择15例在血液透析中反复发生透析性低血压的维持性血透患者190例次,于透析前30分钟口服米多君2.5mg,透析中加用参附注射液50ml,缓慢静滴,观察临床疗效,血压、心率的变化情况。结果总有效率90.6%,透析中最低血压(SBP、DBP)与治疗前比较有明显升高(P<0.001),透析后血压有明显改善(P<0.01)透析中脉搏有显著下降(P<0.05)。结论参附注射液联合小剂量米多君治疗血透性低血压有效且安全。     

复习时突然晕倒不要怕——直立性低血压可以防治

几乎每次高考前期，总有家长来问，孩子好好的在复习，从椅子上站起来时，突然眼前黑蒙蒙，摇晃晃，视物不清，有的会身体支撑不住而跌倒在地，但马上就会醒过来。家长表示不太清楚这到底是怎么回事。     

FDA 批准治疗直立性低血压药物屈昔多巴上市

美国 FDA 于2014年2月18日批准 Chelsea Therapeutics 公司的屈昔多巴（通用名：Droxidopa ,商品名：Northera ）胶囊上市,用于治疗有症状的神经源性直立性低血压（ NOH ）。     

护理干预对直立性低血压患者的疗效影响

目的：探讨护理干预对直立性低血压患者的影响。方法选取收治直立性低血压患者60例作为研究对象,随机分为试验组和对照组各30例,对照组采取常规护理,试验组在对照组基础上进行针对性的护理干预,4周结束后,进行效果比较。结果疗程结束后,两组患者的生活质量都有所改善,试验组患者的改善情况优于对照组,差异有统计学意义（P＜0.05）。结论针对性的护理干预可以明显改善直立性低血压患者的生活质量,提高临床疗效。     

盐酸米多君治疗不完全性高位脊髓损伤后体位性低血压的临床观察

目的初步研究盐酸米多君治疗不完全性高位脊髓损伤后体位性低血压的疗效、斜床起立角度的耐受性及不良反应。方法将15例不完全性脊髓损伤后体位性低血压患者随机分为2组。对照组采用常规治疗,治疗组在常规治疗基础上加用盐酸米多君治疗（5mg,po,tid）。所有病例于治疗前和治疗4周后测平卧位及斜床站立30°、60°位时的血压。治疗前、治疗期间和治疗4周后密切观察临床表现,并进行血糖、肝肾功能、血常规、尿常规检查和B超残余尿量测定。结果不完全性高位脊髓损伤伴有体位性低血压患者治疗前及经盐酸米多君治疗4周后,治疗组与对照组平卧位时的血压无明显变化。治疗4周后斜床站立位的血压,治疗组明显提高（P〈0．05）,可耐受最大斜床站立角度明显提高（P〈0．05）。治疗组患者中1例因卧位高血压,不能耐受退出研究;1例出现竖毛反应,未予特殊处理;1例出现肝功能轻度异常,停药护肝治疗后好转;1例残余尿轻度增加,予间歇导尿后改善。结论盐酸米多君可明显改善不完全性高位脊髓损伤所致的体位性低血压,不良反应轻微。     

Chemical pharmacotherapy for the treatment of orthostatic hypotension

Introduction: Orthostatic hypotension (OH) is a common yet often overlooked condition. Particularly debilitating is neurogenic orthostatic hypotension (nOH) caused by deficient neurotransmission of norepinephrine, which is the primary neurotransmitter released at sympathetic peripheral vascular nerve terminals in response to orthostatic stress.

Areas covered: In this review, the author summarizes and critiques established and emerging pharmacologic approaches for the management of nOH. Two drugs are currently approved. Midodrine, an α₁-adrenoreceptor agonist, acts on capacitance vessels to increase peripheral vascular tone, thus increases arterial pressure. Droxidopa, an orally administered prodrug of norepinephrine, increases circulating norepinephrine levels, causes peripheral vasoconstriction, and increases standing blood pressure. Preliminary studies support the selective use of several off-label drugs in difficult cases. All of these drugs can potentially unmask or exacerbate neurogenic supine hypertension (nSH), which occurs in about half of patients with nOH.

Expert opinion: Chemical pharmacotherapy of nOH is best individualized to the needs and condition of each patient and guided by the underlying pathophysiology, severity of orthostatic incapacity, and minimization of comorbidities such as nSH. The goal of therapy is to maintain cerebral perfusion and increase the patient’s ability to engage in upright daily activities. Advances in pharmacogenetics and ambulatory devices hold promise.     

Pharmacological evidence of alpha1- and alpha2-adrenergic supersensitivity in orthostatic hypotension due to spinal cord injury: a case report

Summary Sympathetic efferent pathways and alpha-adrenergic receptivity were investigated in one patient with spinal cord transection (D1 level) and orthostatic hypotension. The lack of increase in catecholamine plasma levels during orthostasis and the paradoxical pressor effect of clonidine (2 g/kg orally) suggested complete interruption of efferent sympathetic pathways.The pressor response to exogenous noradrenaline was significantly higher in the patient than in 6 normal controls (0.09 vs 0.72 g·kg^–1), indicating supersensitivity of vascular -adrenoceptors. The platelet ₂-adrenergic receptor number, measured with [³H]yohimbine, was 507 in the patient vs 178 fmol·mg^–1 protein in controls. The increase in systolic blood pressure induced by 10 mg midodrine, a specific ₁-agonist, was significantly higher in the patient (=56 mm Hg) than in controls (=15 mm Hg).The results indicate that in the patient there was -adrenergic supersensitivity both of ₁- and ₂-adrenoceptors. This led to successfully oral treatment of the orthostatic hypotension with clonidine 150 g bd and midodrine 10 mg bd.     

盐敏感性高血压患者体位性低血压和体位性高血压与靶器官损害的关系分析

目的:探讨盐敏感性高血压(SSHT)患者体位性高血压(OHT)和体位性低血压(OH)与靶器官损害的关系。方法:选取2018年1月—2020年6月住院的盐敏感性高血压患者380例,对其进行卧立位血压的测量,依据其体位性血压情况分为OH组、OHT组、体位性正常血压(ONT)组,并分析各组的构成比、血压特点以及靶器官损害情况。结果:380例SSHT患者中,OH 85例(22.37%),OHT 64例(16.84%),ONT 231例(60.79%);三组的全天平均血压、白天平均血压及夜间平均血压比较,差异有统计学意义(P<0.05);三组靶器官损害发生率比较,差异有统计学意义(P<0.05)。结论:SSHT患者合并OHT和OH时高血压靶器官损害的发生率高于ONT。     

Droxidopa for the treatment of neurogenic orthostatic hypotension in neurodegenerative diseases

Introduction: L-threo-3,4-dihydroxyphenylserine (droxidopa), a pro-drug metabolized to norepinephrine in nerve endings and other tissues, has been commercially available in Japan since 1989 for treating orthostatic hypotension symptoms in Parkinson’s disease (PD) patients with a Hoehn & Yahr stage III rating, as well as patients with Multiple System Atrophy (MSA), familial amyloid polyneuropathy, and hemodialysis. Recently, the FDA has approved its use in symptomatic neurogenic orthostatic hypotension (NOH).

Areas covered: The authors review the effects of droxidopa in NOH with a focus on the neurodegenerative diseases PD, MSA, and pure autonomic failure (PAF).

Expert opinion: A few small and short placebo-controlled clinical trials in NOH showed significant reductions in the manometric drop in blood pressure (BP) after posture changes or meals. Larger Phase III studies showed conflicting results, with two out of four trials meeting their primary outcome and thus suggesting a positive yet short-lasting effect of the drug on OH Questionnaire composite score, light-headedness/dizziness score, and standing BP during the first two treatment-weeks. Results appear essentially similar in PD, MSA, and PAF. The FDA granted droxidopa approval in the frame of an ‘accelerated approval program’ provided further studies are conducted to assess its long-term effects on OH symptoms.     

米多君加低温透析防治老年人血液透析相关性低血压15例疗效观察

目的探讨多种透析方法在老年人血液透析相关性低血压中的临床应用疗效。方法选择在我院血液净化中心规律治疗6个月以上、入选前2个月内的透析过程中有超过2/3的透析次数中发生低血压的老年维持性血液透析患者15例,所有观察对象均先按原透析方案行3周的透析,共129例次作为对照组（D组）,后随机分为三组：米多君组（A组）、低温透析组（B组）及米多君＋低温透析组（C组）,每种治疗方法实施9周,共387例次,平均129例次/组。观察透析前、后血压、心率,透析过程中每30min测血压、心率,并计算平均动脉压（MAP）,测量患者透析前后体温,观察并记录低血压发生的次数及时间、伴随症状、相关不良反应以及采取的护理干预。结果在降低低血压发生率方面,C组优于A组优于B组;在预防效果方面,C组最佳,A组、B组相比无显著差异;在稳定透析中的低血压方面,A组、B组效果相当,C组效果最佳。结论对于老年人血液透析相关性低血压,选用米多君＋低温透析相结合的治疗方案,能够有效减少IDH的发作频率,保证透析的正常进行,而不良反应却无明显增加,值得临床推广应用。     

米多君治疗血液透析中低血压疗效的临床观察

目的　观察盐酸米多君治疗血液透析中低血压的临床疗效。方法　选择维持性血液透析曾在血液透析中反复发生低血压的慢性肾功能衰竭患者 2 0例 ;在使用盐酸米多君治疗前和治疗后 ,记录血液透析前、透析过程中最低血压和透析结束时的血压。结果　患者无论使用盐酸米多君治疗与否 ,在血液透析过程中均有不同程度的血压下降 ,透析中最低血压低于透析前血压(P <0 0 1 ) ;未使用盐酸米多君治疗时患者透析中最低血压和透析后血压均低于使用盐酸米多君治疗后的相应血压 (P <0 0 1 )。所治疗的患者中未发现有药物副作用发生。结论　盐酸米多君用于防治血液透析中低血压疗效确切 ,副作用少     

Efficacy and safety of midodrine in the treatment of dialysis-associated hypotension

Dialysis-associated hypotension is a morbid problem in haemodialysis patients. Employment of midodrine at the start of dialysis has reduced the severity and frequency of hypotensive episodes in these patients. Through selective α₁-adrenergic receptor-binding, desglymidodrine, the active metabolite of midodrine, raises blood pressure by enhancing venous and arterial tone. This medication has been demonstrated to be effective and safe in the acute and chronic treatment of haemodialysis-associated hypotension in end stage renal disease patients.     

Midodrine: a selective α-adrenergic agonist for orthostatic hypotension and dialysis hypotension

Midodrine is an oral agent which acts as a selective peripherally-acting α-receptor agonist. Midodrine is a prodrug that is almost completely absorbed after oral administration and converted into its active drug de-glymidodrine in the systematic circulation, with a bioavailability of 93%. It has been used successfully in the treatment of neurogenic orthostatic hypotension and more recently, in the treatment of dialysis hypotension. It acts through vasoconstriction of the arterioles and the venous capacitance vessels, thereby increasing peripheral vascular resistance and augmenting venous return, respectively. It is a unique agent in the armamentarium against orthostatic hypotension since it has minimal cardiac and CNS effects. This article will review the literature on midodrine for conditions of autonomic dysfunction, with focus on recent studies on its use in haemodialysis patients.