Clinical evaluation of intravenous labetalol for the treatment of hypertensive urgency

Safety and efficacy of intravenous hydralazine and labetalol for the treatment of asymptomatic hypertension in hospitalised patients: A systematic review

BACKGROUND

Current guidelines for the management of asymptomatic hypertension (HTN) in the inpatient setting recommend the use of oral antihypertensives. However, in clinical practice, intravenous (IV) antihypertensives are commonly utilised with little supporting evidence. The objective of this study was to evaluate literature examining the safety/efficacy of IV hydralazine and labetalol in hospitalised patients with non-emergent, asymptomatic HTN.

METHODS

The PRISMA guidelines were utilised to structure the systematic review. A search strategy composed of drug-, inpatient- and HTN-related terms was conducted utilising PubMed, Embase and Scopus databases through May 2020. Full-text, English-language articles describing IV labetalol and/or hydralazine use for non-emergent HTN in an inpatient setting that focused on clinical outcomes (ie vitals, adverse effects, healthcare utilisation) were included. Identified studies were screened/extracted using DistillerSR by two reviewers at each stage, and studies were evaluated qualitatively for the presence of bias.

RESULTS

From 3362 records identified in the search, a final set of 10 articles were identified. Four studies focused on labetalol (40%), five studies on hydralazine and labetalol (50%), and one study on hydralazine (10%). The included studies presented a variety of outcomes, but several trends were identified, including reduction in average blood pressure in eight (80%) studies, a risk of adverse effects in six (60%) and increased length of stay in one (10%).

DISCUSSION

The studies identified in this review raise concerns regarding the safety of IV hydralazine and labetalol in non-emergent HTN. Despite relatively broad clinical experience with these drugs, experimental investigations regarding their utility are recommended.

Management of hypertensive crises in the elderly

Hypertensive crises are elevations of blood pressure higher than 180/120 mmHg. These can be urgent or emergent, depending on the presence of end organ damage. The clinical presentation of hypertensive crises is quite variable in elderly patients, and clinicians must be suspicious of non-specific symptoms. Managing hypertensive crises in elderly patients needs meticulous knowledge of the pathophysiological changes in them, pharmacological options, pharmacokinetics of the medications used, their side effects, and their interactions with other medications. Clevidipine, nicardipine, labetalol, esmolol, and fenoldopam are among the preferred choices in the elderly due to their efficacy and tolerability. Nitroprusside, hydralazine, and nifedipine should be avoided, unless there are no other options available, due to the high risk of complications and unpredictable responses.

Pharmacologic Treatment of Hypertensive Urgency in the Outpatient Setting: A Systematic Review

BACKGROUND

Hypertensive urgency (HU), defined as acute severe uncontrolled hypertension without end-organ damage, is a common condition. Despite its association with long-term morbidity and mortality, guidance regarding immediate management is sparse. Our objective was to summarize the evidence examining the effects of antihypertensive medications to treat.

METHODS

We searched the PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE), Cochrane Database of Systematic Reviews, Web of Science, Google Scholar, and Embase through May 2016.

STUDY SELECTION

We evaluated prospective controlled clinical trials, case-control studies, and cohort studies of HU in emergency room (ER) or clinic settings. We initially identified 11,223 published articles. We reviewed 10,748 titles and abstracts and identified 538 eligible articles. We assessed the full text for eligibility and included 31 articles written in English that were clinical trials or cohort studies and provided blood pressure data within 48 h of treatment. Studies were appraised for risk of bias using components recommended by the Cochrane Collaboration. The main outcome measured was blood pressure change with antihypertensive medications. Since studies were too diverse both clinically and methodologically to combine in a meta-analysis, tabular data and a narrative synthesis of studies are presented.

RESULTS

We identified only 20 double-blind randomized controlled trials and 12 cohort studies, with 262 participants in prospective controlled trials. However, we could not pool the results of studies. In addition, comorbidities and their potential contribution to long-term treatment of these subjects were not adequately addressed in any of the reviewed studies.

CONCLUSIONS

Longitudinal studies are still needed to determine how best to lower blood pressure in patients with HU. Longer-term management of individuals who have experienced HU continues to be an area requiring further study, especially as applicable to care from the generalist.

High-Risk Patients with Hypertension: Clinical Management Options

Hypertension, one of the most common human diseases worldwide, affects nearly 1 billion individuals. Complaints related to hypertension are commonly evaluated and treated in the acute care settings such as emergency departments and acute care medical clinics. The evaluation, treatment, and disposition of these patients require thorough knowledge of potential complications and treatment options. This manuscript details a structured approach to evaluating high-risk patients with acute hypertension-related complaints and provides recommendations for treatment and disposition.

Characteristics and management of patients presenting to the emergency department with hypertensive urgency

Few studies have examined the characteristics of patients presenting with hypertensive urgency, factors contributing to their presentation, or their management. The time and cost associated with treatment are unknown. Retrospective analysis of 50 emergency department patients with hypertensive urgency (symptomatic blood pressure (BP) elevation focusing on systolic BP >180 mm Hg or diastolic BP >110 mm Hg) was performed. The hospital database was queried to determine the cost of the average treat-and-release visit. The mean age was 54.3+/-15.6 years; 64% were female; 46% were black; 90% had diagnosed hypertension. The mean presenting BP was 198+/-27.6/109+/-17.3 mm Hg; 66% had systolic BP >180 mm Hg, and 38% had diastolic BP >110 mm Hg. Initially, 30% were not on antihypertensives, and 28% were on monotherapy. Headache (42%) and dizziness (30%) were most frequently reported symptoms. Presentation was most often attributed to running out of medication (16%). IV and oral labetalol were given to 28% and 24% of patients, respectively. Fifty-six percent of patients had no change in baseline therapy at discharge. The average emergency department stay was 5 hours 17 minutes +/- 4 hours 27 minutes. The average cost for similar visits in 2004 was 1543 dollars per visit. Emergency department visits for hypertensive urgency are related mostly to noncompliance. Labetalol was the most frequently used therapy. Management in the primary care office could result in substantial cost savings.

A comparative study between a calcium channel blocker (Nicardipine) and a combined alpha-beta-blocker (Labetalol) for the control of emergence hypertension during craniotomy for tumor surgery

We compared the efficacy of the combination of enalaprilat/labetalol with that of enalaprilat/nicardipine to prevent emergence postcraniotomy hypertension. A prospective, randomized open labeled clinical trial was designed to compare the incidence of breakthrough hypertension (systolic blood pressure [SBP] > 140 mm Hg) and adverse effects (hypotension, tachycardia, and bradycardia) between the two drug combinations. Secondarily, the effects of the drugs on SBP, mean blood pressure, and diastolic blood pressure were evaluated over the course of the study. Forty-two patients received enalaprilat 1.25 mg IV at dural closure followed by either multidose nicardipine 2 mg IV or labetalol 5 mg IV to maintain the SBP below 140 mm Hg. SBP was similarly controlled in both groups. There was a marginally smaller incidence of failures and adverse effects with labetalol. Blood pressure profiles were similar for both groups.

Diagnosis and management of hypertensive emergencies

It has been estimated that approximately 600,000 to 800,000 Americans will develop a hypertensive crisis (Calhoun and Oparil, 1990). Although such numbers represent only about 1% of the estimated 60 million Americans with hypertension, hypertensive crisis often constitutes a major medical emergency, necessitating a focused, assertive, and reasoned therapeutic intervention. When such patients are seen in the emergency department or in a physician's office with a critical elevation in blood pressure (BP), appropriate and efficacious management is essential to avoid catastrophic injury to vital target organs, including the central nervous system, the heart, and the kidneys. Delays in initiating effective therapy or, equally important, overzealous therapy leading to a too-rapid reduction in BP can produce severe complications involving these target organs. This article reviews the spectrum of clinical syndromes that comprise hypertensive emergencies, highlighting 2 to illustrate the complexities of clinical presentation and management. The newly advocated treatment guidelines based on the category of acute severe hypertension (including asymptomatic hypertensive urgencies) are also considered, as are therapeutic strategies utilizing currently available antihypertensive agents.

Course of blood pressure within the first 12 h of hypertensive urgencies

OBJECTIVE

To evaluate the course of blood pressure within 12 h of a hypertensive urgency with or without oral antihypertensive treatment prior to discharge of patients from hospital.

DESIGN

A prospective, double-blinded, placebo-controlled and randomized clinical trial.

SETTING

Department of Emergency Medicine in a 2000-bed inner city hospital.

PATIENTS

Forty patients successfully treated for a hypertensive urgency with intravenous administration of urapidil.

INTERVENTIONS

We administered 60 mg urapidil orally or placebo prior to discharge of patients from hospital and evaluated the course of blood pressure within 12 h of the urgency by use of an ambulatory blood pressure measurement unit.

MAIN OUTCOME MEASURES

Mean systolic and diastolic blood pressures within the first 12 h of a hypertensive urgency and the number of hypertensive and hypotensive episodes.

RESULTS

Mean systolic and diastolic blood pressures were significantly lower in members of the urapidil group than they were in members of the placebo group (132 +/- 14 versus 147 +/- 18 mmHg, P = 0.003; 79 +/- 12 versus 87 +/- 14 mmHg, P = 0.047, respectively). The number of hypotensive episodes was similar for these two groups (three versus one, P = 0.32), whereas the number of hypertensive episodes was significantly lower for the urapidil group (13 versus 34, P = 0.001).

CONCLUSIONS

Oral medication with urapidil prior to discharge results in lower overall blood pressure levels and reduces the risk of hypertensive episodes recurring within 12 h of a hypertensive urgency. Therefore, we recommend this therapeutic approach for patients with hypertensive urgencies, who are treated with an intravenous antihypertensive drug.

Intravenous urapidil versus sublingual nifedipine in the treatment of hypertensive urgencies

In a 6-month prospective study, the efficacy and safety of urapidil and nifedipine in an outpatient population with hypertensive urgencies (systolic blood pressure > 200 mm Hg; diastolic blood pressure > 110 mm Hg) was investigated. Response to treatment was defined as a stable reduction of systolic blood pressure below 180 mm Hg and diastolic blood pressure below 100 mm Hg 15 minutes after application of a single dose of either 25 mg urapidil intravenously (N = 26) or 10 mg nifedipine sublingually (N = 27). If the blood pressure was still elevated, a second dose of 10 mg nifedipine or 12.5 mg urapidil was given, and blood pressure response was evaluated 15 minutes after application of the second dose according to the aforementioned criterias. After the first application of nifedipine, 19 (70%) responders have been observed. Eight patients needed an additional 10 mg of nifedipine. In four of these patients, no reduction of blood pressure was observed after a second dose of nifedipine. In contrast, 24 (92%) patients responded well to the first application of 25 mg of urapidil. Two patients required a second dose of 12.5 mg of urapidil, but no nonresponder to urapidil was observed. No severe side-effects were noted in both groups. Intravenous urapidil is a highly effective drug in the treatment of hypertensive urgencies and is more effective than sublingual nifedipine, because the number of patients treated successfully was significantly higher.

Oral labetalol versus oral clonidine in the emergency treatment of severe hypertension

This study was designed to compare the clinical efficacy and safety of oral clonidine and oral labetalol in the treatment of severe hypertension in an emergency department setting. Thirty-six patients with severely elevated blood pressure (mean baseline blood pressure 199/132 mm Hg) without acute end-organ dysfunction were treated with either oral labetalol or oral clonidine in a randomized double-blind prospective study. Labetalol was administered as an initial dose of 200 mg, followed by hourly 200 mg doses up to 1,200 mg. Clonidine was administered as an initial dose of 0.2 mg, followed by hourly 0.1 mg doses up to 0.7 mg. Labetalol reduced diastolic blood pressure in 94% of the patients within 6 hours, with a mean reduction in blood pressure of 54/37 mm Hg. Clonidine reduced diastolic blood pressure in 83% of the patients within 6 hours, with a mean reduction in blood pressure of 57/32 mm Hg. The authors conclude that oral labetalol was comparable to clonidine in efficacy, had a similar incidence of side effects, and offered the clinician a useful alternative for the treatment of severe hypertension in an emergency department setting. Further studies are indicated to determine appropriate dosing regimens for oral labetalol in the acute treatment of severe hypertension.

Labetalol. A reappraisal of its pharmacology, pharmacokinetics and therapeutic use in hypertension and ischaemic heart disease

Since labetalol was first reviewed in the Journal (1978), its scope of therapeutic use has expanded and become better defined. Labetalol is an adrenoceptor blocking drug with combined alpha- and beta-blocking properties. These result in a more favourable haemodynamic profile for labetalol compared with 'pure' beta-blockers or pure alpha-blockers, but also contribute to a wider range, but not an overall increased incidence, of adverse effects. The drug is effective and well-tolerated in patients with all grades of hypertension, but is of particular value in special subgroups such as Black patients, the elderly and patients with renal hypertension. While comparative studies are not extensive, available data show that the drug reduces blood pressure to a similar extent, and in a similar proportion of patients, as 'pure' beta-blockers such as propranolol, pure alpha-blockers such as prazosin, calcium antagonists (nifedipine, verapamil), and centrally acting drugs (clonidine and methyldopa). Labetalol is very effective in hypertensive pregnant women and in hypertensive crises, where it provides good control of blood pressure without serious adverse effects, and where few therapeutic options exist. Few controlled studies have investigated the use of labetalol in deliberate induction of hypotension or prevention of hypertension during anaesthesia, and also in patients with ischaemic heart disease. However, available evidence suggests a role for labetalol in these indications and further studies should aid in clarification of its efficacy in these areas. Thus, with its broad scope of therapeutic use in hypertension labetalol remains an important therapeutic option, and the drug may well find an additional place in the treatment of myocardial ischaemia if further evidence confirms encouraging preliminary findings.