Comparison of sublingual captopril, nifedipine and prazosin in hypertensive emergencies during hemodialysis

Effect of Fast-Disintegrating Tablets' Characteristics on the Sublingual Permeability of Atropine Sulfate for the Potential Treatment of Organophosphates Toxicity

Atropine sulfate (AS) fast-disintegrating sublingual tablets (FDSTs) were tested for AS sublingual permeation's feasibility as a potential alternative dosage form to treat organophosphates (OP) toxicity. More than 12,000 OP pesticide toxicity cases were reported in the USA from 2011 to 2014. AS is the recommended antidote for OP toxicity; however, it is only available as an ATROPEN® auto-injector, an IM injection, for self-administration, which is associated with several drawbacks and limitations. Six AS FDST batches were formulated and characterized. Two tablet sizes, group A weighing 150 mg and group B weighing 50 mg, were formulated with three different AS doses: 2 mg (A1 and B1), 4 mg (A2 and B2), and 8 mg (A3 and B3). AS in vitro diffusion and sublingual permeation were investigated in Franz cells using a cellulose membrane and an excised porcine sublingual membrane. The effect of AS load and tablet size on sublingual permeation was also evaluated. All batches passed quality control tests. AS FDSTs' size and AS load had a significant effect on tablet disintegration time and drug dissolution, which significantly impacted AS concentration gradient across the diffusional membrane. Group B FDSTs (smaller tablets) resulted in a significantly higher initial permeation (JAUC_0-15) compared to group A FDSTs. Also, the cumulative AS (JAUC_0-90) and AS influx (J) increased linearly with increasing AS dose. These AS FDSTs have the potential to be explored in vivo to determine the required bioequivalent sublingual AS dose as an alternative dosage form for the treatment of OP toxicity.

Blood Pressure Management in Acute Stroke: Comparison of Current Guidelines with Prescribing Patterns

Objective:

Current recommendations for treating elevated blood pressure (BP) in the acute stroke are based largely on expert opinion and vary with regard to treatment thresholds and choice of antihypertensive agents. In this study we investigate the influence of these recommendations by comparing the management of hypertension in acute stroke at a tertiary care hospital with current guidelines.

Method:

Retrospective chart review of patients admitted with acute stroke at The Ottawa Hospital-General Campus over six consecutive months. The use of antihypertensive medications (type, dose, routes of administration, BP recordings) in the first seven days after admission was noted.

Results:

Transdermal nitroglycerin paste was the most commonly used antihypertensive agent. In contrast to the 15% reduction in BP over 24 hours recommended for lowering BP in hypertensive patients with ischemic stroke, nitroglycerin caused a >15% reduction of BPover the first 24 hours on 60% of the occasions used. Furthermore, despite concerns about sublingual nifedipine, this was the second most commonly prescribed agent. Surprisingly, the mean time to first BP measurement following initiation of antihypertensive therapy was 117 ± 43 minutes in ischemic stroke and 88 ± 89 minutes in hemorrhagic strokes.

Conclusions:

The current guidelines for management of acute poststroke hypertension appear to have little influence on prescribing patterns, leading to considerable variations in practice. Such variations, likely due to uncertainty caused by lack of evidence from randomised controlled trials, are intolerable as patients maybe submitted to nonstandardised, potentially harmful care such as inappropriate choice of antihypertensives and inadequate BP monitoring as observed in this study.

Safer Alternatives to Sublingual Nifedipine for the Treatment of Hypertensive Urgencies

Objective:

To determine safer alternatives to sublingual administration of nifedipine for acute BP reduction.

Data Sources:

English-language articles were retrieved from a MEDLINE search (1992–1997) using the following search terms: Angiotensin-converting enzyme inhibitor administration, sublingual, hypertensive emergency, and nifedipine. Standard references were also consulted.

Study Selection:

Representative articles addressing the use of sublingual nifedipine, captopril, or oral medications in acute hypertensive situations were reviewed and relevant studies were selected and analyzed.

Data Synthesis:

Sublingual captopril, nifedipine, and oral and sublingual Clonidine have been used in the management of acute hypertension. Oral labetalol, topical and sublingual nitrates, and other medications have also been evaluated for the treatment of hypertensive urgencies and emergencies. Sublingual nifedipine and captopril have a rapid onset of action and are effective in quickly lowering elevated BP. Sublingual use of nifedipine is associated with severe adverse effects and fatalities. Sublingual captopril offers similar reductions in BP without many severe adverse effects.

Conclusions:

For patient safety, sublingual nifedipine is no longer available for the treatment of hypertensive emergencies or urgencies at the Louisville Veterans Affairs Medical Center. When oral medications are requested for acute BP reduction, captopril is administered. Sublingual or oral Clonidine is the alternative for patients in whom captopril is contraindicated. Use of immediate-release nifedipine has been reduced by 98%.

Pattern of Blood Pressure Response in Patients With Severe Asymptomatic Hypertension Treated in the Emergency Department

Severe asymptomatic hypertension (SAH) is a common cause of emergency department (ED) visits. Despite recommendations against using short-acting blood pressure (BP)-lowering drugs in the ED, it is still a common practice. The authors characterized BP response in the ED utilizing 24-hour ambulatory BP monitoring (ABPM). Patients with SAH who were not admitted to the hospital were recruited. All patients underwent 24-hour ABPM. A total of 21 patients (14 females) with a mean age of 58±16 years were studied. BP decreased from 199±16/101±17 mm Hg to 154±34/83±23 mm Hg after 5 hours but then rose to 174±25/94±17 mm Hg after 19 hours. In 17 patients, systolic BP was ≥180 mm Hg after 6.7±5.3 hours. Two patients experienced severe hypotension (systolic BP <90 mm Hg). Thus, data from a single site in Israel support the current recommendations for management of SAH in the ED.

Hypertensive emergencies: an update

PURPOSE OF REVIEW

Systemic hypertension (HTN) is a common medical condition affecting over 1 billion people worldwide. One to two percent of patients with HTN develop acute elevations of blood pressure (hypertensive crises) that require medical treatment. However, only patients with true hypertensive emergencies require the immediate and controlled reduction of blood pressure with an intravenous antihypertensive agent.

RECENT FINDINGS

Although the mortality from hypertensive emergencies has decreased, the prevalence and demographics of this disorder have not changed over the last 4 decades. Clinical experience and reported data suggest that patients with hypertensive urgencies are frequently inappropriately treated with intravenous antihypertensive agents, whereas patients with true hypertensive emergencies are overtreated with significant complications.

SUMMARY

Despite published guidelines, most patients with hypertensive crises are poorly managed with potentially severe outcomes.

Pharmacological interventions for hypertensive emergencies

BACKGROUND

Hypertensive emergencies, marked hypertension associated with acute end-organ damage, are life-threatening conditions. Many anti-hypertensive drugs have been used in these clinical settings. The benefits and harms of such treatment and the best first-line treatment are not known.

OBJECTIVES

To answer the following two questions using randomized controlled trials (RCTs): 1) does anti-hypertensive drug therapy as compared to placebo or no treatment affect mortality and morbidity in patients presenting with a hypertensive emergency? 2) Does one first-line antihypertensive drug class as compared to another antihypertensive drug class affect mortality and morbidity in these patients?

SEARCH STRATEGY

Electronic sources: MEDLINE, EMBASE, Cochrane clinical trial register. In addition, we searched for references in review articles and trials. We attempted to contact trialists. Most recent search August 2007.

SELECTION CRITERIA

All unconfounded, truly randomized trials that compare an antihypertensive drug versus placebo, no treatment, or another antihypertensive drug from a different class in patients presenting with a hypertensive emergency.

DATA COLLECTION AND ANALYSIS

Quality of concealment allocation was scored. Data on randomized patients, total serious adverse events, all-cause mortality, non-fatal cardiovascular events, withdrawals due to adverse events, length of follow-up, blood pressure and heart rate were extracted independently and cross checked.

MAIN RESULTS

Fifteen randomized controlled trials (representing 869 patients) met the inclusion criteria. Two trials included a placebo arm. All studies (except one) were open-label trials. Seven drug classes were evaluated in those trials: nitrates (9 trials), ACE-inhibitors (7), diuretics (3), calcium channel blockers (6), alpha-1 adrenergic antagonists (4), direct vasodilators (2) and dopamine agonists (1). Mortality event data were reported in 7 trials. No meta-analysis was performed for clinical outcomes, due to insufficient data. The pooled effect of 3 different anti-hypertensive drugs in one placebo-controlled trial showed a statistically significant greater reduction in both systolic [WMD -13, 95%CI -19,-7] and diastolic [WMD -8, 95%CI, -12,-3] blood pressure with antihypertensive therapy.

AUTHORS' CONCLUSIONS

There is no RCT evidence demonstrating that anti-hypertensive drugs reduce mortality or morbidity in patients with hypertensive emergencies. Furthermore, there is insufficient RCT evidence to determine which drug or drug class is most effective in reducing mortality and morbidity. There were some minor differences in the degree of blood pressure lowering when one class of antihypertensive drug is compared to another. However, the clinical significance is unknown. RCTs are needed to assess different drug classes to determine initial and longer term mortality and morbidity outcomes.

Monitoring therapeutic interventions in critically ill septic patients

Sepsis is the leading cause of admission to intensive care units in the United States. Although the treatment of sepsis is complex and multimodal, nutrition support plays an important role in the management of these patients. The diagnosis of sepsis, disease category, and severity of illness and the change in sepsis severity and organ function over time affect the delivery of nutrition support. This paper reviews the diagnostic criteria of sepsis, the use of "sepsis biomarkers," and regional and global markers of organ function in sepsis and quantitative measures of illness severity and organ dysfunction.

Calcium antagonists

Calcium antagonists were introduced for the treatment of hypertension in the 1980s. Their use was subsequently expanded to additional disorders, such as angina pectoris, paroxysmal supraventricular tachycardias, hypertrophic cardiomyopathy, Raynaud phenomenon, pulmonary hypertension, diffuse esophageal spasms, and migraine. Calcium antagonists as a group are heterogeneous and include 3 main classes--phenylalkylamines, benzothiazepines, and dihydropyridines--that differ in their molecular structure, sites and modes of action, and effects on various other cardiovascular functions. Calcium antagonists lower blood pressure mainly through vasodilation and reduction of peripheral resistance. They maintain blood flow to vital organs, and are safe in patients with renal impairment. Unlike diuretics and beta-blockers, calcium antagonists do not impair glucose metabolism or lipid profile and may even attenuate the development of arteriosclerotic lesions. In long-term follow-up, patients treated with calcium antagonists had development of less overt diabetes mellitus than those who were treated with diuretics and beta-blockers. Moreover, calcium antagonists are able to reduce left ventricular mass and are effective in improving anginal pain. Recent prospective randomized studies attested to the beneficial effects of calcium antagonists in hypertensive patients. In comparison with placebo, calcium antagonist-based therapy reduced major cardiovascular events and cardiovascular death significantly in elderly hypertensive patients and in diabetic patients. In several comparative studies in hypertensive patients, treatment with calcium antagonists was equally effective as treatment with diuretics, beta-blockers, or angiotensin-converting enzyme inhibitors. From these studies, it seems that a calcium antagonist-based regimen is superior to other regimens in preventing stroke, equivalent in preventing ischemic heart disease, and inferior in preventing congestive heart failure. Calcium antagonists are also safe and effective as first-line or add-on therapy in diabetic hypertensive patients. Heart rate-lowering calcium antagonists (verapamil, diltiazem) may have an edge over the dihydropyridines in post-myocardial infarction patients and in diabetic nephropathy. Thus, calcium antagonists may be safely used in the management of hypertension and angina pectoris.

Clinical review: the management of hypertensive crises

Hypertension is an extremely common clinical problem, affecting approximately 50 million people in the USA and approximately 1 billion individuals worldwide. Approximately 1% of these patients will develop acute elevations in blood pressure at some point in their lifetime. A number of terms have been applied to severe hypertension, including hypertensive crises, emergencies, and urgencies. By definition, acute elevations in blood pressure that are associated with end-organ damage are called hypertensive crises. Immediate reduction in blood pressure is required only in patients with acute end-organ damage. This article reviews current concepts, and common misconceptions and pitfalls in the diagnosis and management of patients with acutely elevated blood pressure.

Evaluation of captopril for the management of hypertension in autonomic dysreflexia: a pilot study

OBJECTIVE

To evaluate the efficacy of captopril for management of hypertensive urgencies in autonomic dysreflexia.

DESIGN

A 1-year, prospective, open-label pilot study.

SETTING

Rehabilitation hospital.

PATIENTS

Twenty-six consecutive patients older than 15 years with spinal cord injury above T6.

INTERVENTIONS

During an autonomic dysreflexia episode, captopril 25mg was administered sublingually if systolic blood pressure (SBP) was at or above 150mmHg despite the use of nondrug measures. If SBP remained elevated 30 minutes after captopril administration, 1 dose of immediate-release nifedipine 5mg was given as rescue by the bite and swallow method and repeated, if necessary, in 15 minutes.

MAIN OUTCOME MEASURE

SBP 30 minutes after captopril administration at initial autonomic dysreflexia episode.

RESULTS

A total of 33 autonomic dysreflexia episodes were documented, of which 18 episodes in 5 patients were treated with drug therapy. Captopril alone was effective in 4 of 5 initial episodes (80%). Mean SBPs at baseline and 30 minutes after captopril were 178+/-18mmHg and 133+/-28mmHg, respectively. There were no cases of reactive hypotension. The addition of nifedipine successfully reduced SBP in the remaining patient. Of the combined 18 initial and repeat autonomic dysreflexia episodes, 94% were successfully treated with our protocol.

CONCLUSION

Captopril appears to be safe and effective for autonomic dysreflexia management.

Current concepts in the management of hypertensive crisis: emergencies and urgencies

Hypertensive emergencies and hypertensive urgencies represent a large percentage of major medical emergencies and have the potential of producing serious organ damage or death if not treated promptly and selectively. Several classifications of antihypertensive agents are discussed, with emphasis on selecting agents appropriate for patients' hypertension manifestations and comorbid situations. Epidemiology and evaluation of hypertension, as well as common pharmacokinetics of several common and new oral and parenteral antihypertensive agents, are described. Special nursing considerations of medication administration and gerontology concepts are included.

The diagnosis and management of hypertensive crises

Severe hypertension is a common clinical problem in the United States, encountered in various clinical settings. Although various terms have been applied to severe hypertension, such as hypertensive crises, emergencies, or urgencies, they are all characterized by acute elevations in BP that may be associated with end-organ damage (hypertensive crisis). The immediate reduction of BP is only required in patients with acute end-organ damage. Hypertension associated with cerebral infarction or intracerebral hemorrhage only rarely requires treatment. While nitroprusside is commonly used to treat severe hypertension, it is an extremely toxic drug that should only be used in rare circumstances. Furthermore, the short-acting calcium channel blocker nifedipine is associated with significant morbidity and should be avoided. Today, a wide range of pharmacologic alternatives are available to the practitioner to control severe hypertension. This article reviews some of the current concepts and common misconceptions in the management of patients with acutely elevated BP.

A Comparison of Safety and Efficacy of Sublingual Captopril with Sublingual Nifedipine in Hypertensive Crisis

Sublingual nifedipine is commonly used in hypertensive crisis, however, it may result in several adverse effects such as reflex tachycardia, headache, and flushing. Research is continuing to find a new drug that has the same efficiency and fewer side effects. Sublingual captopril, a new preparation of angiotensin-converting enzyme inhibitor, lowers blood pressure. It is not known whether it is effective in these emergent clinical settings. Therefore we designed a randomized, double-blind study to compare the efficacy and safety of those two drugs in hypertensive crisis. Eighty patients (32 male and 48 female) with hypertensive crisis were included in the study; their mean age was 43.4 +/- 7.9 years. Nifedipine 10 mg was given sublingually to 34 and captopril 25 mg to 46 patients randomly. There was no difference between the two drugs with respect to their antihypertensive effect. Heart rate significantly dropped (p < 0.01 and p < 0.001) in the patients taking captopril, but no changes were observed in the patients taking nifedipine. Twenty-three of 34 patients taking nifedipine encountered adverse effects. Adverse effects were observed in only three patients taking captopril (p < 0.001). Sublingual captopril is as effective as and has less side effects than sublingual nifedipine. Because sublingual captopril has fewer side effects, it may be safer than nifedipine in the treatment of hypertensive crisis.http://link.springer-ny.com/link/service/journals/00547/bibs/8n3p147.html

ED hemodialysis for treatment of renal failure emergencies

Patients with chronic renal failure (CRF) are at risk for unique medical emergencies, many of which require hemodialysis for their definitive treatment. This study describes the use of emergency department (ED) hemodialysis in the management of CRF patients. A retrospective chart review was conducted of patients who underwent ED hemodialysis at a regional dialysis center between April 1994 and September 1996. Data were collected on presenting complaint, ED diagnosis, indication for hemodialysis, ED pharmacologic treatment, ED airway management, cardiovascular stability, and disposition. Fifty episodes of ED hemodialysis were identified in 37 different patients. Presenting complaints included: shortness of breath, 38 (69%); weakness, 8 (15%); chest pain, 3 (5%); and other, 6 (11%). ED diagnoses included: congestive heart failure, 36 (65%); hyperkalemia, 13 (24%); and other, 6 (11%). Indications for hemodialysis included: cardiovascular instability, 33 (38%); respiratory distress, 22 (26%); cardiac monitoring, 16 (19%), timing, 13 (15%); and other, 2 (2%). Predialysis stabilization included: nitroglycerin, 29 (26%); sublingual captopril, 17 (15%); calcium chloride, 13 (11%); sodium bicarbonate, 12 (11%); insulin/dextrose, 11 (10%); none, 12 (11%); and other, 18 (16%). Airway support included: noninvasive pressure support ventilation (NPSV), 9 (18%); and endotracheal intubation, 6 (12%). NPSV was provided with a bilevel positive airway pressure system. Three of the endotracheal intubation patients were weaned to NPSV during dialysis, and all NPSV patients were weaned from respiratory support during their hemodialysis in the ED. Some patients had more than one problem. Sixteen patients (32%) were admitted, while 34 (68%) were discharged, including 3 NPSV patients and 22 initially unstable patients. ED hemodialysis in conjunction with additional medical care is a useful emergency medicine technique that can prevent hospital admission in patients with acute renal emergencies.

Asymptomatic hypertension in the ED

A retrospective study in an urban, municipal, teaching hospital emergency department (ED) was conducted to evaluate (1) the frequency of asymptomatic hypertension in the ED, (2) the initial assessment and patterns of treatment by physicians, and (3) the changes in blood pressure (BP) in these patients. Patients with systolic BP > or = 180 mm Hg or diastolic BP > or = 110 mm Hg were included. Patients with cardiovascular, renal, or central nervous system dysfunction were excluded. Of the 11,531 charts reviewed, 269 (2.3%) met inclusion criteria. Of the 269 patients, 56 patients (20.8%) received antihypertensive treatment in the ED. The treatment group had a higher systolic BP (P < .001), diastolic BP (P < .001), and mean arterial blood pressure (MAP) (P < .001) than the nontreatment group. Fundoscopy was also performed more frequently in the treatment group (30.2% v 8.9%, P < .001). MAP decreased for both groups in the ED, but was higher in the treatment group (-20+/-21 v -11+/-21 mm Hg, P=.02). Despite the lack of support in the literature for the emergency treatment of asymptomatic hypertension in the ED, the individual physician's decision for treatment correlated with the degree of hypertension. Significantly elevated BP readings in the ED tended to decrease over time independent of any antihypertensive treatment, although the decrease was larger in the treated patients.

Influence of repeated prazosin administration on cardiovascular responses in rats and rabbits

Prazosin was injected i.v. at a dose of 50 micrograms/kg every 2 h for 8 h in conscious rats. Its hypotensive action significantly declined. A similar effect was also observed in rabbits pretreated with prazosin (40 micrograms/kg, i.v.) every 1 h for 4 h. In prazosin-treated rabbits, the total peripheral resistance became less responsive to phentolamine stimulation. Repeated prazosin administration abolished its ability to block receptors in a model of anococcygue muscle contraction after noradrenaline (NA) stimulation. The alpha-adrenoceptors in anococcygue muscle exhibited lower pD2 to NA and lower pA2 to prazosin in prazosin-treated rats. The results demonstrate that repeated prazosin administration reduces the effectiveness of alpha-adrenoceptors blockers.