Physiologic Treatment of Severe Hypertension in Pregnancy and Postpartum

We aimed to evaluate physiologic treatment of severe hypertension. This was a retrospective cohort study of pregnant and postpartum patients with severe hypertension (systolic blood pressure [BP] 160 mm Hg or higher or diastolic BP 110 mm Hg or higher) treated with intravenous labetalol or hydralazine at a single tertiary care center between 2013 and 2018. Patients were classified as having physiologic treatment if they had hyperdynamic physiology (pulse pressure 65 mm Hg or higher) and received labetalol or had vasoconstrictive physiology (diastolic BP 100 mm Hg or higher) and received hydralazine. The primary outcome was number of antihypertensive doses to achieve nonsevere BP. Of 1,120 patients included in the analysis, 653 had physiologic treatment and 467 had nonphysiologic treatment, with 16 (1.4%) excluded for inability to classify physiology. Physiologic treatment was associated with fewer antihypertensive doses (1.4±0.9 doses vs 1.6±1.4 doses; adjusted β -0.28, 95% CI, -0.42 to -0.14) and lower odds of medication conversion (2.5% vs 4.7%; adjusted odds ratio 0.48, 95% CI, 0.24-0.93) but no difference in time to nonsevere BP (31 minutes [interquartile range 16-66 minutes] vs 34 minutes [interquartile range 15-76 minutes]; adjusted hazard ratio 1.0, 95% CI, 0.9-1.2). Physiologic treatment of severe hypertension warrants further evaluation.

Overlapping drug-induced vasculitis, ANCA-associated vasculitis, and lupus nephritis caused by low-dose hydralazine

INTRODUCTION

We present a case of drug-induced vasculitis secondary to low-dose hydralazine with overlapping features of antineutrophil cytoplasmic antibody-associated vasculitis and drug-induced lupus nephritis.

CASE PRESENTATION

A 52-year-old Hispanic woman with a medical history of resistant hypertension treated with hydralazine 10 mg twice daily for 1 year presented with generalized weakness, dizziness, nausea, vomiting, and gross hematuria. There was fever, tachycardia, leukocytosis, lactic acidosis, hyperkalemia, renal failure, and anemia. Chest computed tomography and bronchoscopy revealed a left lower lobe infiltrate and diffuse alveolar hemorrhage. Serologic testing was positive for anti-double-stranded DNA, anti-Smith, lupus anticoagulant, anti-histone, anti-cardiolipin IgM antibodies, and antineutrophil cytoplasmic antibodies (myeloperoxidase and proteinase 3). A kidney biopsy revealed crescentic glomerulonephritis with an overlapping finding of membranous nephropathy. Broad-spectrum antibiotics, immunosuppressants, corticosteroids, and plasmapheresis were initiated. The patient survived but required continuous hemodialysis.

CONCLUSIONS

Although a few cases of simultaneous antibody-associated vasculitis and drug-induced lupus nephritis secondary to hydralazine use have been reported, this case is singular. Similar findings were previously reported with doses of 50-100 mg two to three times daily over 1-5 years. In our patient, a dose of only 10 mg twice daily for a year caused a severe disease presentation. This brings to light the combination of different vasculitides that can coexist and the potentially life-threatening adverse effects of low-dose hydralazine that should be kept in mind.

Reduction of Intravenous Antihypertensives through Clinical Decision Support in a Large Safety Net System

BACKGROUND

Asymptomatic severe hypertension (also known as hypertensive urgency) is frequently encountered in the hospital. Previous evidence suggests that management with one-time doses of intravenous (IV) antihypertensives may increase adverse events. Despite this, single-dose treatment remains common in the emergency department and inpatient settings.

METHODS

This quality initiative was launched at New York City Health + Hospitals, the largest safety net hospital system in the United States. The initiative involved two changes to electronic orders for IV hydralazine and IV labetalol: a nonintrusive advisory statement within the order instructions and a mandatory requirement to document the indication for IV antihypertensive use.

RESULTS

This initiative took place from November 2021 to October 2022. Of the indications selected for IV antihypertensive orders, 60.7% were for hypertensive emergency, 15.3% were for patients who were strictly NPO, 21.2% were for other, and 2.8% selected more than one indication. For ED-only encounters, aggregate IV hydralazine and IV labetalol orders per 1,000 patient encounters were 2.53 preintervention and 1.55 postintervention (38.7% reduction, p < 0.001). For inpatient encounters, aggregate IV hydralazine and IV labetalol orders per 1,000 patient-days were 18.25 preintervention and 15.81 postintervention (13.4% reduction, p < 0.001). Similar trends were observed for individual orders of IV hydralazine and IV labetalol. There were significant reductions in 7 of the 11 hospitals in inpatient administration of aggregate IV hydralazine and labetalol orders per 1,000 patient-days.

CONCLUSION

This quality improvement initiative successfully reduced unnecessary IV antihypertensive use in an 11-hospital safety net system.

Hydralazine-induced liver injury: a review and discussion

Hydralazine is a commonly prescribed antihypertensive agent. Some of its labelled adverse reactions include lupus-like syndrome, tachycardia, headache and fever. Despite its well-known side effects, little is known about hydralazine's hepatotoxic effects. We report the case of a 54-year-old female patient who was started on hydralazine for hypertension management but later presented with hydralazine-induced liver injury. Her initial presentation consisted of non-specific symptoms and a hepatocellular injury pattern. Liver biopsy revealed hepatic steatosis. Three weeks after discontinuation of hydralazine, the patient's liver enzymes normalised, and her symptoms resolved. Few studies have examined the incidence and mechanism by which hydralazine induces a liver injury pattern. With this case, we review the literature, the pathogenesis involved and the eventual management of hydralazine-induced liver injury. We propose close monitoring of liver enzymes for patients on hydralazine throughout their treatment course.

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.

Hydralazine-Induced ANCA Associated Vasculitis (AAV) Presenting with Pulmonary-Renal Syndrome (PRS): A Case Report with Literature Review

Hydralazine, an arterial vasodilator, is a widely used medication for the management of hypertension and heart failure, especially for patients who cannot tolerate the use of ACEIs or ARBs. It is generally well-tolerated and has a safe profile in pregnancy. However, hydralazine can induce immune-mediated side effects, such as hydralazine-induced lupus and less commonly hydralazine- induced ANCA vasculitis. The latter most commonly affects the kidneys with or without other organ involvement. There are several cases reported in the literature of hydralazine-induced ANCA associated vasculitis (AAV) that have pulmonary manifestations, also known as hydralazine- induced pulmonary-renal syndrome (PRS), a condition with a high risk of mortality. We are reporting a case of Hydralazine-induced ANCA associated glomerulonephritis with severe diffuse alveolar hemorrhage (DAH). In addition, we will review the current literature and discuss the importance of prompt diagnosis and early management to decrease mortality and morbidity associated with this serious condition.

Hyperbaric oxygen therapy for perioperative posterior ischemic optic neuropathy: a case report

PURPOSE

To report the successful treatment of postoperative posterior ischemic optic neuropathy (PION) with hyperbaric oxygen therapy and to review the current literature on the pathogenesis and treatment of PION.

OBSERVATIONS

During an angiographic procedure at a community hospital, an elderly woman had a transient drop in blood pressure after receiving an intravenous dose of hydralazine. During recovery, the patient experienced bilateral vision loss. She was transferred to our specialty referral center for treatment with hyperbaric oxygen. We followed Table 5 in the U.S. Navy Diving Manual, the protocol for decompression sickness. Our patient's vision improved markedly immediately after the first session and continued to improve throughout the course of treatment to its completion. Follow-up ophthalmology visits found the patient's vision to be close to baseline.

CONCLUSIONS AND IMPORTANCE

PION is a rare condition. It has been difficult to determine a successful therapeutic approach because of the lack of large case-controlled studies. Hyperbaric oxygen has been used to treat other ischemic ophthalmic conditions, but there are only few reports of its use in patients with PION. Systemic steroids and antiplatelet therapy have also been used, with mixed success. In our patient, the combination of hyperbaric oxygen therapy and steroids was successful in restoring vision after postoperative PION.

Successful use of rituximab for hydralazine-induced anti-neutrophil cytoplasmic antibodies-associated vasculitis

Hydralazine is a commonly used anti-hypertensive medication. It can, however, contribute to the development of autoimmunity, in the form of drug-induced lupus and anti-neutrophil cytoplasmic antibodies-associated vasculitis. We report a 45-year-old patient with hypertension managed with hydralazine for four years who presented with rapidly progressive glomerulonephritis (RPGN), requiring hemodialysis, and diffuse alveolar hemorrhage (DAH), requiring mechanical ventilation, and extracorporeal membrane oxygenation. The patient's autoantibody profile was consistent with a drug-induced autoimmune process and renal histology revealed focal necrotizing crescentic GN. She was treated with high-dose steroids, plasma exchange and rituximab. DAH resolved and her renal function improved, allowing discontinuation of hemodialysis. This case reveals that rituximab can be successfully used in the setting of hydralazine-induced vasculitis, including critically ill patients with severe DAH and acute kidney injury from RPGN.

Drug-induced Hemolysis in G6PD Deficiency: an Unusual Presentation of a Common Clinical Condition

Glucose-6-phosphate dehydrogenase (G6PD) deficiency can present a diagnostic dilemma owing to the varying degrees of disease severity and the wide range of precipitating factors. Here, we report a case of a 56-year-old man who presented with signs and symptoms of heart failure and, during the course of treatment, developed intravascular hemolysis. On investigation, he was found to be G6PD deficient. Following discontinuation of the fixed-dose combination of isosorbide dinitrate and hydralazine, the clinical condition of the patient improved, and there were no further episodes of hemolysis. The case highlights the need for a high degree of suspicion of G6PD deficiency in patients with unexplained signs and symptoms of intravascular hemolysis.

Drugs for treating severe hypertension in pregnancy: a network meta-analysis and trial sequential analysis of randomized clinical trials

AIMS

Several antihypertensive drugs are used in the treatment of severe hypertension in pregnancy. The present study is a network meta-analysis comparing the efficacy and safety of these drugs.

METHODS

Electronic databases were searched for randomized clinical trials comparing drugs used in the treatment of severe hypertension in pregnancy. The number of women achieving the target blood pressure (BP) was the primary outcome. Doses required and time taken for achieving the target BP, failure rate, and incidences of maternal tachycardia, palpitation, hypotension, headache, and neonatal death and stillbirth were the secondary outcomes. Mixed treatment comparison pooled estimates were generated using a random-effects model. Odds ratios for the categorical and mean difference for the numerical outcomes were the effect estimates.

RESULTS

Fifty-one studies were included in the systematic review and 46 in the meta-analysis. No significant differences in the number of patients achieving target BP was observed between any of the drugs. Diazoxide [-15 (-20.6, -9.4)], nicardipine [-11.8 (-22.3, -1.2)], nifedipine/celastrol [-19.3 (-27.4, -11.1)], nifedipine/vitamin D [-17.1 (-25.7, -9.7)], nifedipine/resveratrol [-13.9 (-22.6, -5.2)] and glyceryl trinitrate [-33.8 (-36.7, -31)] were observed to achieve the target BP (in minutes) more rapidly than hydralazine. Nifedipine required fewer doses than hydralazine for achieving the target BP. Glyceryl trinitrate and labetalol were associated with fewer incidences of tachycardia and palpitation respectively than hydralazine. Trial sequential analysis concluded adequate evidence for hydralazine and nifedipine compared with labetalol. Moderate quality of evidence was observed for direct comparison estimate between labetalol and hydralazine but was either low or very low for other comparisons.

CONCLUSION

The present evidence suggests similar efficacy between nifedipine, hydralazine and labetalol in the treatment of severe hypertension in pregnancy. Subtle differences may exist in their safety profile. The evidence is inadequate for other drugs.

Drug-induced lupus erythematosus: an update on drugs and mechanisms

PURPOSE OF REVIEW

Rapid introduction of newly developed drugs in the absence of clear understanding of the pathophysiologic mechanisms behind drug-induced lupus erythematosus (DILE) can sometimes make DILE difficult to recognize in clinical practice. The purpose of this review is to summarize drugs most recently reported to be involved in DILE and discuss the current landscape of diverse mechanisms involved.

RECENT FINDINGS

A large number of proton pump inhibitor (PPI)-induced subacute cutaneous lupus erythematosus cases have been reported, suggesting a shift over time in the spectrum of drugs implicated in DILE. Twenty-two articles comprising 29 DILE case reports published within the last 2 years are summarized in this review, including 12 (41.4%) systemic DILE. Antitumor necrosis factor (anti-TNF) drugs were the most frequently (41.7%) reported to introduce systemic DILE in these cases. Chemotherapeutic drugs were the most common drug class (54.5%) involved in subacute cutaneous lupus erythematosus, with an observed higher incidence in female patients. Enhanced neutrophil extracellular trap (NET) formation induced by procainamide and hydralazine could be a new mechanism contributing to the pathogenesis of DILE.

SUMMARY

The list of drugs implicated in triggering DILE is expanding as new drugs with novel mechanisms of action are being developed. It is important to recognize culprit drugs that may induce lupus erythematosus, as discontinuation usually results in improvement of drug-induced manifestations. Characterizing the mechanisms involved might help better understand the cause of idiopathic autoimmunity.

Hydralazine-Induced ANCA Vasculitis in the Setting of Acute Clostridium Difficile Infection

We report a rare case of Hydralazine-induced ANCA associated glomerulonephritis with alveolar hemorrhage in the setting of acute Clostridium Difficile Infection. A 71-year-old Caucasian woman with hypertension, who was being treated with hydralazine 25 mg twice a day for six years, presented to the hospital with diarrhea, nausea, vomiting and anemia. She had acute kidney injury and urinalysis showed proteinuria, dysmorphic RBCs, and rare RBC cast. She was found to have Clostridium difficile colitis which was successfully treated. She became hypoxemic; CT scan findings showed bilateral pulmonary infiltrates. Broncho-alveolar lavage was consistent with pulmonary hemorrhage. Kidney biopsy revealed focal segmental necrotizing and diffuse crescentic glomerulonephritis, pauci-immune type (ANCA-associated). Hydralazine was discontinued and the patient was treated with corticosteroids, intravenous cyclophosphamide and plasmapheresis. To our knowledge, hydralazine-associated low complement in the setting of C-diff infection has not been previously reported. This is considered a potentially life-threatening condition requiring immediate discontinuation of the offending medication and expedited lifesaving measures. [Full article available at http://rimed.org/rimedicaljournal-2016-11.asp].

Use of hydralazine-isosorbide dinitrate combination in African American and other race/ethnic group patients with heart failure and reduced left ventricular ejection fraction

BACKGROUND

Hydralazine-isosorbide dinitrate (H-ISDN) therapy is recommended for African American patients with moderate to severe heart failure with reduced ejection fraction (<40%) (HFrEF), but use, temporal trends, and clinical characteristics associated with H-ISDN therapy in clinical practice are unknown.

METHODS AND RESULTS

An observational analysis of 54 622 patients admitted with HFrEF and discharged home from 207 hospitals participating in the Get With The Guidelines-Heart Failure registry from April 2008 to March 2012 was conducted to assess prescription, trends, and predictors of use of H-ISDN among eligible patients. Among 11 185 African American patients eligible for H-ISDN therapy, only 2500 (22.4%) received H-ISDN therapy at discharge. In the overall eligible population, 5115 of 43 498 (12.6%) received H-ISDN at discharge. Treatment rates increased over the study period from 16% to 24% among African Americans and from 10% to 13% among the entire HFrEF population. In a multivariable model, factors associated with H-ISDN use among the entire cohort included younger age; male sex; African American/Hispanic ethnicity; and history of diabetes, hypertension, anemia, renal insufficiency, higher systolic blood pressure, and lower heart rate. In African American patients, these factors were similar; in addition, being uninsured was associated with lower use.

CONCLUSIONS

Overall, few potentially eligible patients with HFrEF are treated with H-ISDN, and among African-Americans fewer than one-fourth of eligible patients received guideline-recommended H-ISDN therapy. Improved ways to facilitate use of H-ISDN therapy in African American patients with HFrEF are needed.

[Clinical efficacy and perinatal outcome of nifedipine for severe preeclampsia: meta-analysis]

OBJECTIVE

To assess the efficacy, side effects and perinatal outcome of nifedipine compared with other antihypertensives for treating severe preeclampsia in pregnant women.

METHODS

Randomized controlled trials (RCTs) that comparing nifedipine with other antihypertensives for severe preeclampsia were searched in PubMed, EMBase, Cochrane library, CNKI and VIP database etc(till January 2012). The quality of the included RCTs was evaluated, and Meta-analysis was performed with Rev Man 5.1 software.

RESULTS

Nine trials were included, involving 386 women in the nifedipine group, and 378 women in other antihypertensives group. Compared with other antihypertensives, nifidepine was associated with greater effective control of blood pressure (OR = 2.65, 95%CI: 1.65 - 4.25, P < 0.01). There was no clear difference in the time needed to control blood pressure (WMD = -3.64, 95%CI: -10.90 - 3.61, P = 0.32). Nifedipine could prolong gestation better than other antihypertensives (WMD = 5.14, 95%CI: 3.29 - 6.99, P < 0.01). There were no clear differences in maternal side effects headache (P = 0.28), palpitation (P = 0.06), and nausea vomiting (P = 0.28). No noticeable difference was found between the two groups in the Apgar score at five minutes (WMD = -0.21, 95%CI: -0.32 - 0.91, P = 0.72), neonatal respiratory distress syndrome (OR = 1.24, 95%CI: 0.57 - 2.67, P = 0.59), or perinatal deaths (OR = 0.49, 95%CI: 0.22 - 1.11, P = 0.09).

CONCLUSION

Nifedipine is associated with greater effective control of blood pressure and prolongation of gestation, with no additional neonatal respiratory distress syndrome or perinatal deaths, compared with other antihypertensives for women with severe preeclampsia.

Attenuation of mouse somatic and emotional inflammatory pain by hydralazine through scavenging acrolein and inhibiting neuronal activation

BACKGROUND

Acrolein signaling is important during spinal cord injury; whether it is involved in somatic and emotional pain is not clear. Hydralazine is a potent antihypertensive drug and can scavenge acrolein efficiently.

OBJECTIVE

We hypothesized that hydralazine decreases spinal level acrolein and renders analgesic effects with some side effects, which was tested in the current study.

STUDY DESIGN

Subcutaneous injection of formalin was used to induce somatic and emotional pain responses. The spinal neuronal activation (FOS expression) and acrolein expression were evaluated at 2 hours after subcutaneous formalin injection. The possible side effects of hydralazine on the murine central nervous system or cardiovascular system were evaluated at one hour after hydralazine injection with open field, elevated plus maze and rotarod tests, or telemetrical measurement of mean artery blood pressure and heart rate.

RESULTS

The subcutanous injection of formalin into the left hind paw induced significant somatic and emotional pain responses, evaluated by the biphasic spontaneous flinch/licking of the injected hind paw and interphase ultrasonic vocalizations during the one hour window after formalin injection. The spinal acrolein level was significantly increased and neurons were activated at 2 hours after formalin injection. Intraperitoneal injection of hydralazine (at 0.1, 1 or 10 mg/kg of body weight) at one hour before formalin challenging dose-dependently attenuated the formalin induced pain responses with an analgesic 50% effect dose ranging from 0.2 to 1 mg/kg of body weight. Furthermore, the neuronal activation and elevated acrolein expression were dose-dependently inhibited by hydralazine pretreatment. The side effects of intraperitoneal hydralazine on locomotion, anxiety, and motor coordination at one hour after hydralazine administration had negative results. The main side effects of hydralazine were an insignificant decrease of blood pressure and a significant increase of heart rates at high dose (10 mg/kg of body weight).

LIMITATIONS

This study is limited because the analgesic effect of hydralazine was tested on only one type of acute inflammatory pain model; however, its effect on chronic inflammatory or neuropathic pain needs to be further investigated.

CONCLUSIONS

Based on the above findings, hydralazine may find its new application of analgesia within a safe dose window (around one mg/kg of body weight) without causing severe side effects.

Epigenetic therapy with hydralazine and magnesium valproate reverses imatinib resistance in patients with chronic myeloid leukemia

The epigenetic drugs hydralazine and valproate were administered in a compassionate manner to 8 patients with chronic myeloid leukemia (CML) refractory to imatinib. Two patients had a complete hematologic response (25%),1 major cytogenetic response, 1 complete cytogenetic response (25% any cytogenetic response), and 3 (37.5%)stable disease. No grade 3 or 4 toxicity was observed. These results show the ability of epigenetic therapy to revert imatinib resistance.

BACKGROUND

Epigenetic alterations participate in the development of acquired resistance to imatinib, hence, the DNA methylation, and histone deacetylase inhibitors hydralazine and valproate, respectively, has the potential to overcome it.

PATIENT AND METHODS

A series of 8 patients with chronic myeloid leukemia (CML) refractory to imatinib mesylate with no access to second-generation tyrosine kinase inhibitors were treated with hydralazine and valproate in a compassionate manner. Clinical efficacy and safety of these drugs added to imatinib mesylate were evaluated.

RESULTS

Two patients were in the blast phase, 5 were in the accelerated phase, and 1 was in the chronic phase. All the patients continued with the same dose of imatinib that they had been receiving at the time of development of resistance, with a median dose of 600 mg daily (range, 400-800 mg). The median time from diagnosis of CML to the start of hydralazine and valproate was 53.6 months (range, 19-84 months). Two (25%) patients had a complete hematologic response, one (12.5%) had an major cytogenetic response, and one (12.5%) had a complete cytogenetic response. Three (37.5%) patients had stable disease, and only one (12.5%) patient failed to respond. At a median follow-up time of 18 months (range, 3-18 months), the median survival had not been reached, and the projected overall survival was 63%. All the patients had mild neurologic toxicity, including distal tremor and somnolence. No grade 3 or 4 toxicity was observed.

CONCLUSIONS

Our results suggest that the epigenetic drugs hydralazine and valproate revert the resistance to imatinib in patients with CML.

Sweet syndrome associated with hydralazine-induced lupus erythematosus

Sweet syndrome (SS) is a distinctive but poorly understood clinical syndrome, which likely represents an immunologic reaction pattern to a wide range of underlying or preceding conditions, including viral illnesses, inflammatory bowel disease, and malignancies. We report the case of a patient who presented with an acute eruption that was clinically and histologically consistent with SS. The patient also met diagnostic criteria for systemic lupus erythematosus with serositis, stomatitis, positive antinuclear antibody (ANA), and positive anti-double-stranded DNA antibodies. Additionally, positive antihistone antibodies and exposure to hydralazine supported the specific diagnosis of drug-induced lupus erythematosus, and we concluded that his SS was a manifestation of hydralazine-induced lupus. We also briefly review the precedence for this unusual dual diagnosis in the literature.

Vasodilator therapy with hydralazine induces angiotensin AT receptor-mediated cardiomyocyte growth in mice lacking guanylyl cyclase-A

BACKGROUND AND PURPOSE

Recent clinical guidelines advocate the use of the isosorbide dinitrate/hydralazine combination in treatment for heart failure. However, clinical and laboratory evidence suggest that some vasodilators may induce cardiac hypertrophy under uncertain conditions. This study investigated the effects and underlying mechanism of action of the vasodilator hydralazine on cardiac growth.

EXPERIMENTAL APPROACH

Wild-type mice and animals deficient in guanylyl cyclase-A (GCA) and/or angiotensin receptors (AT(1) and AT(2) subtypes) were treated with hydralazine ( approximately 24 mg.kg(-1).day(-1) in drinking water) for 5 weeks. Cardiac mass and/or cardiomyocyte cross-sectional area, fibrosis (van Giessen-staining) and cardiac gene expression (real-time RT-PCR) were measured.

KEY RESULTS

Hydralazine lowered blood pressure in mice of all genotypes. However, this treatment increased the heart and left ventricular to body weight ratios, as well as cardiomyocyte cross-sectional area, and cardiac expression of atrial natriuretic peptide mRNA in mice lacking GCA. Hydralazine did not affect cardiac hypertrophy in wild-type mice and mice lacking either AT(1) or AT(2) receptors alone. However, the pro-hypertrophic effect of hydralazine was prevented in mice lacking both GCA and AT(2), but not GCA and AT(1) receptors. However, hydralazine did decrease cardiac collagen deposition and collagen I mRNA (signs of cardiac fibrosis) in mice that were deficient in GCA, or both GCA and AT(2) receptors.

CONCLUSIONS AND IMPLICATIONS

The vasodilator hydralazine induced AT(2) receptor-mediated cardiomyocyte growth under conditions of GCA deficiency. However, attenuation of cardiac fibrosis by hydralazine could be beneficial in the management of cardiac diseases.

Evaluation of once daily hydralazine in inadequately controlled hypertension

Despite the short plasma half-life of hydralazine, once daily Slow Apresoline has been shown to maintain blood pressure control in well controlled hypertension. In the present investigation of 118 inadequately controlled hypertensives, we have shown that 50-150 mg Slow Apresoline once daily induces a significant blood pressure reduction and is well tolerated. Normotension, i.e. supine diastolic blood pressure less than 95 mmHg, was reached in 53% of the patients. Normotension or a supine diastolic blood pressure reduction of greater than or equal to 10 mmHg was achieved in 72% of the patients, the hydralazine responders. Sixteen patients discontinued treatment due to symptoms probably related to hydralazine. Acetylator phenotyping showed that slow acetylators predominated in the group of patients discontinuing hydralazine due to side-effects. In contrast, 90% of the phenotyped non-responders were rapid acetylators, which suggests a suboptimal use of hydralazine in some rapid acetylators.

Treatment of hypertension in middle-aged men. A feasibility study in a community

In a health examination survey of 2322 middle-aged men the prevalence of hypertension, defined as supine DBP greater than or equal to 105 mmHg and including those on treatment, was 7.5%. All untreated and those inadequately treated were invited to a hypertension clinic. One year's treatment in 86 men achieved a BP reduction of 29/17 mmHg in supine and 27/16 mmHg in erect position. This reduction was maintained for a three-year period and considered satisfactory in 80% of subjects. Propranolol, alone or in combination with other agents, was used in more than 80% of the cases. Special considerations in treating asymptomatic individuals are discussed.

Peripheral vasodilatation in the treatment of hypertension. Prazosin compared with hydralazine in patients not responding to beta-receptor blockade

Prazosin was compared with hydralazine in 39 patients (mean age 49 years), who were already on beta-blockade for arterial hypertension. They all had a resting DBP greater than 100 mm Hg on propranolol 80 mg b i d. They were randomly allocated to prazosin or hydralazine treatment. Blood pressure was measured after 4, 8 and 12 weeks. We noted a significant fall in blood pressure in both groups, in most cases to normotensive levels. Side-effects and other variables of interest are discussed. Together with beta blockade, i e propranolol, both prazosin and hydralazine give good blood-pressure control and no important differences could be found.

Acetylator phenotype in patients with hydralazine-induced lupoid syndrome

The acteylator phenotype has been determined (isoniazid half-life) in 31 patients, 25 of them women, who had exhibited a lupus erythematosus-like syndrome during treatment with hydralazine. Twenty-nine patients were slow acetylators, one was rapid (probably spontaneous SLE) and one uncertain. Only two patients had been given more than 200 mg of hydralazine daily. The mean duration of therapy was 32 months at the onset of symtoms. These were not serious but rather long-standing. Our study confirms that patients who risk developing hydralazine lupus are slow acetylators, especially females, treated with more than 100 mg daily. Rapid acetylators seem to develop this side-effect rarely, if at all.

Hydralazine-associated glomerulonephritis

Nine patients (6 men, 3 women) with rapidly progressive glomerulonephritis developing during hydralazine therapy were seen. Early cessation of hydralazine treatment resulted in improvement in seven patients, while continued hydralazine treatment resulted in permanent renal insufficiency in two. The clinical symptoms of systemic illness associated with the hydralazine syndrome were absent in most patients. Antinuclear antibody test was positive in all, and six investigated patients had antibodies to histones. All patients had anemia, high ESR, and microscopic hematuria. Five of the nine patients were rapid drug acetylators. Renal biopsies from eight patients revealed a uniform histologic picture with segmental necrosis of glomeruli and extracapillary proliferation. Immunofluorescence investigation was positive in all and electron microscopy revealed deposits in the glomerular capillary walls in five of seven specimens. This renal disease may represent a late and monosymptomatic manifestation of the hydralazine syndrome.

Immunological side-effects of antihypertensive drugs

The immunological side-effects under treatment with antihypertensive drugs are mainly limited to autoimmunity and autoimmune disease caused by alpha-methyldopa and hydralazine. Autoimmune hemolytic anemia is more common during treatment with alpha-methyldopa. Hydralazine may induce antinuclear antibodies. Some patients develop a SLE-like syndrome. Its clinical picture is less severe and its prognosis is more favourable than that of spontaneous SLE. During treatment with low doses the disease develops exclusively in patients who are slow acetylators. It may appear also in rapid acetylators during the high dose treatment. The symptoms are usually reversible after withdrawal of the drug.

A phase II study of epigenetic therapy with hydralazine and magnesium valproate to overcome chemotherapy resistance in refractory solid tumors

BACKGROUND

Epigenetic aberrations lead to chemotherapy resistance; hence, their reversal by inhibitors of DNA methylation and histone deacetylases may overcome it.

PATIENTS AND METHODS

Phase II, single-arm study of hydralazine and magnesium valproate added to the same schedule of chemotherapy on which patients were progressing. Schedules comprised cisplatin, carboplatin, paclitaxel, vinorelbine, gemcitabine, pemetrexed, topotecan, doxorubicin, cyclophosphamide, and anastrozole. Patients received hydralazine at 182 mg for rapid, or 83 mg for slow, acetylators, and magnesium valproate at 40 mg/kg, beginning a week before chemotherapy. Response, toxicity, DNA methylation, histone deacetylase activity, plasma valproic acid, and hydralazine levels were evaluated.

RESULTS

Seventeen patients were evaluable for toxicity and 15 for response. Primary sites included cervix (3), breast (3), lung (1), testis (1), and ovarian (7) carcinomas. A clinical benefit was observed in 12 (80%) patients: four PR, and eight SD. The most significant toxicity was hematologic. Reduction in global DNA methylation, histone deacetylase activity, and promoter demethylation were observed.

CONCLUSIONS

The clinical benefit noted with the epigenetic agents hydralazine and valproate in this selected patient population progressing to chemotherapy' and re-challenged with the same chemotherapy schedule after initiating hydralazine and valproate' lends support to the epigenetic-driven tumor-cell chemoresistance hypothesis (ClinicalTrials.gov Identifier: NCT00404508).

BiDil (isosorbide dinitrate and hydralazine): a new fixed-dose combination of two older medications for the treatment of heart failure in black patients

BiDil is a new fixed-dose combination of 2 older medications, isosorbide dinitrate (ISDN) and hydralazine. ISDN is an organic nitrate that is biotransformed into nitric oxide, a potent vasodilator. Hydralazine is believed to have both vasodilatory properties specific to the arteries and antioxidant properties, which address both the biochemical alterations in the failing cardiovascular system as well as the issue of nitrate tolerance. A drug regimen combining an NO stimulator (ISDN) with an antioxidant (hydralazine) favorably influences the nitroso-redox balance. Retrospective analyses of previous heart failure (HF) clinical trials comparing the combination of ISDN and hydralazine with placebo and enalapril, respectively, demonstrated a benefit in the black population, setting the precedent for a race-based therapeutic study, the African-American Heart Failure Trial (A-HeFT). A-HeFT examined the use of BiDil added to standard HF therapy in blacks with New York Heart Association functional class III and IV HF. BiDil demonstrated a 43% reduction in mortality when compared with placebo. As a result, current evidence-based treatment guidelines recommend that the addition of ISDN and hydralazine in black patients with moderate to severe HF optimized on standard therapy be considered. BiDil is currently indicated for the treatment of HF as an adjunct to standard therapy in black patients. The use of BiDil for black patients with mild disease or in nonblack patients with HF has not been studied. Future clinical trials involving an ethnically and clinically diverse population of patients would further define the role of combined ISDN and hydralazine in the treatment of HF.

Isosorbide dinitrate and hydralazine hydrochloride: a review of efficacy and safety

In the USA alone, there are over 5,000,000 people diagnosed with heart failure. A disproportionate number of African-Americans are affected by this disease, with increased morbidity and mortality, yet they are tremendously under-represented in clinical trials. Several drugs have been approved for use in heart failure based on clinical trials, with percentages of African-American subjects as low as 1%. In the African-American Heart Failure Trial the use of BiDil, a drug combining isosorbide dinitrate and hydralazine hydrochloride, demonstrated a 43% decrease in overall mortality and a 39% decrease in first hospitalization. The combination consists of 20 mg of isosorbide and 37.5 mg hydralazine hydrochloride in a fixed dose that functions as a nitric oxide enhancer and an antioxidant, and helps to prevent tolerance to the prolonged use of nitrate. The hemodynamic effects of the combination drug in heart failure includes increased cardiac output. The US Food and Drug Administration approved the combination of isosorbide dinitrate based on the African-American Heart Failure Trial. Further clinical trials utilizing isosorbide dinitrate will hopefully determine the benefit of this combination in a larger population, including caucasians and other racial/ethnic groups.

Hydralazine-induced Lupus: Maintaining Vigilance with Increased Use in Patients with Heart Failure

OBJECTIVE

To review data concerning the incidence and danger of hydralazine-induced systemic lupus erythematosus (SLE) and review how best to monitor patients placed on chronic hydralazine therapy.

DATA SOURCES

Literature was sought utilizing PUBMED (1960 to present) and MEDLINE (1966 to present). Search terms included hydralazine, drug-induced systemic lupus erythematosus, congestive heart failure, and antinuclear antibody.

DATA SYNTHESIS

A major adverse effect of hydralazine therapy is drug-induced SLE. An evaluation of case reports and review of the literature was undertaken to determine the significance of this major adverse effect and stress the importance of close monitoring of patients placed on chronic hydralazine therapy for heart failure. Risk factors are discussed including high daily doses, slow acetylator and HLA-DRw4 phenotypes, therapy longer than 3 months, and female gender.

CONCLUSIONS

Following the publication of A-HeFT, an increase in the amount of hydralazine prescribed in patients with heart failure has been noted. Patients should be closely monitored when initiating hydralazine and during chronic therapy. Although dose limitation of hydralazine reduces risk, low doses are well documented to be associated with SLE. A baseline antinuclear antibody level should be determined on initiation of hydralazine, but it is not recommended to regularly check antinuclear antibody levels because a positive result does not necessarily indicate SLE is present. Patients should be monitored at each visit for signs and symptoms of SLE, and, if any signs and symptoms of the syndrome develop while the patient is on hydralazine therapy, the drug should be discontinued immediately because complications from the syndrome can be potentially fatal.

The oxidative stress concept of nitrate tolerance and the antioxidant properties of hydralazine

The hemodynamic and anti-ischemic effects of nitroglycerin (NTG) are rapidly blunted as a result of the development of nitrate tolerance. With initiation of NTG therapy, it is possible to detect neurohormonal activation and intravascular volume expansion. These so-called pseudotolerance mechanisms may compromise the vasodilatory effects of NTG. Long-term nitrate treatment also is associated with decreased vascular responsiveness caused by changes in intrinsic mechanisms of the tolerant vasculature itself. According to the oxidative stress concept, increased vascular superoxide (O2-) production and an increased sensitivity to vasoconstrictors secondary to activation of protein kinase C contribute to the development of tolerance. Nicotinamide adenine dinucleotide phosphate oxidase and the uncoupled endothelial nitric oxide synthase may be O2- -producing enzymes. Nitric oxide (NO) and O2-, both derived from NTG and the vessel wall, form peroxynitrite in a diffusion-limited rapid reaction. Peroxynitrite, O2-, or both may be responsible for the development of nitrate tolerance and cross-tolerance to direct NO donors (eg, sodium nitroprusside, sydnonimines) and endothelium-dependent NO synthase-activating vasodilators. Hydralazine is an efficient reactive oxygen species (ROS) scavenger and an inhibitor of O2- generation. When given concomitantly with NTG, hydralazine prevents the development of nitrate tolerance and normalizes endogenous rates of vascular O2- production. Recent experimental work has defined new tolerance mechanisms, including inhibition of the enzyme that bioactivates NTG (ie, mitochondrial aldehyde dehydrogenase isoform 2 [ALDH2]) and mitochondria as potential sources of ROS. NTG-induced ROS inhibit the bioactivation of NTG by ALDH2. Both mechanisms increase oxidative stress and impair NTG bioactivation, and now converge at the level of ALDH2 to support a new theory for NTG tolerance and NTG-induced endothelial dysfunction. The consequences of these processes for NTG downstream targets (eg, soluble guanylyl cyclase, cyclic guanosine monophosphate-dependent protein kinase), toxic effects contributing to endothelial dysfunction (eg, prostacyclin synthase inhibition) and novel applications of the antioxidant properties of hydralazine are discussed.

Combination of isosorbide dinitrate and hydralazine in blacks with heart failure

BACKGROUND

We examined whether a fixed dose of both isosorbide dinitrate and hydralazine provides additional benefit in blacks with advanced heart failure, a subgroup previously noted to have a favorable response to this therapy.

METHODS

A total of 1050 black patients who had New York Heart Association class III or IV heart failure with dilated ventricles were randomly assigned to receive a fixed dose of isosorbide dinitrate plus hydralazine or placebo in addition to standard therapy for heart failure. The primary end point was a composite score made up of weighted values for death from any cause, a first hospitalization for heart failure, and change in the quality of life.

RESULTS

The study was terminated early owing to a significantly higher mortality rate in the placebo group than in the group given isosorbide dinitrate plus hydralazine (10.2 percent vs. 6.2 percent, P=0.02). The mean primary composite score was significantly better in the group given isosorbide dinitrate plus hydralazine than in the placebo group (-0.1+/-1.9 vs. -0.5+/-2.0, P=0.01; range of possible values, -6 to +2), as were its individual components (43 percent reduction in the rate of death from any cause [hazard ratio, 0.57; P=0.01] 33 percent relative reduction in the rate of first hospitalization for heart failure [16.4 percent vs. 22.4 percent, P=0.001], and an improvement in the quality of life [change in score, -5.6+/-20.6 vs. -2.7+/-21.2, with lower scores indicating better quality of life; P=0.02; range of possible values, 0 to 105]).

CONCLUSIONS

The addition of a fixed dose of isosorbide dinitrate plus hydralazine to standard therapy for heart failure including neurohormonal blockers is efficacious and increases survival among black patients with advanced heart failure.

Hydralazine for treatment of severe hypertension in pregnancy: meta-analysis

OBJECTIVE

To review outcomes in randomised controlled trials comparing hydralazine against other antihypertensives for severe hypertension in pregnancy.

STUDY DESIGN

Meta-analysis of randomised controlled trials (published between 1966 and September 2002) of short acting antihypertensives for severe hypertension in pregnancy. Independent data abstraction by two reviewers. Data were entered into RevMan software for analysis (fixed effects model, relative risk and 95% confidence interval); in a secondary analysis, risk difference was also calculated.

RESULTS

Of 21 trials (893 women), eight compared hydralazine with nifedipine and five with labetalol. Hydralazine was associated with a trend towards less persistent severe hypertension than labetalol (relative risk 0.29 (95% confidence interval 0.08 to 1.04); two trials), but more severe hypertension than nifedipine or isradipine (1.41 (0.95 to 2.09); four trials); there was significant heterogeneity in outcome between trials and differences in methodological quality. Hydralazine was associated with more maternal hypotension (3.29 (1.50 to 7.23); 13 trials); more caesarean sections (1.30 (1.08 to 1.59); 14 trials); more placental abruption (4.17 (1.19 to 14.28); five trials); more maternal oliguria (4.00 (1.22 to 12.50); three trials); more adverse effects on fetal heart rate (2.04 (1.32 to 3.16); 12 trials); and more low Apgar scores at one minute (2.70 (1.27 to 5.88); three trials). For all but Apgar scores, analysis by risk difference showed heterogeneity between trials. Hydralazine was associated with more maternal side effects (1.50 (1.16 to 1.94); 12 trials) and with less neonatal bradycardia than labetalol (risk difference -0.24 (-0.42 to -0.06); three trials).

CONCLUSIONS

The results are not robust enough to guide clinical practice, but they do not support use of hydralazine as first line for treatment of severe hypertension in pregnancy. Adequately powered clinical trials are needed, with a comparison of labetalol and nifedipine showing the most promise.