Management of prostacyclin side effects in adult patients with pulmonary arterial hypertension

Pulmonary Hypertension in Children

Pulmonary hypertension (PH) may manifest at any age, including during childhood. While pediatric PH frequently associates with early life alterations that cause occult or overt pulmonary vascular disease, all forms of PH seen in adults are also found in children, although with different degrees of prevalence according to PH subtype. PH-specific medications, rapid implementation of therapeutic advances, multidisciplinary teams for improved child and family support, and programs to facilitate successful transition to adult care have contributed to substantial improvement in survival to adulthood.

Practical management of oral treprostinil in patients with pulmonary arterial hypertension: Lessons from ADAPT, EXPEDITE, and expert consensus

BACKGROUND

Oral treprostinil is a prostacyclin analogue approved to treat pulmonary arterial hypertension (PAH) by delaying disease progression and improving exercise capacity. Higher doses of oral treprostinil correlate with increased treatment benefit. Titrations may be challenging due to common side effects of prostacyclin-class therapies.

STUDY DESIGN AND METHODS

The multicenter, prospective, real-world, observational ADAPT Registry study followed adult patients with PAH for up to 78 weeks after initiating oral treprostinil (NCT03045029). Dosing, titration, and transitions of oral treprostinil were at the discretion of the prescriber. Patient-reported incidence and treatment of common side effects were collected to understand side effect management and tolerability. Insights from literature and expert recommendations were added to provide a consolidated resource for oral treprostinil use.

RESULTS

In total, 139 participants in ADAPT completed ≥1 weekly survey; (median age 60.0 years, 76 % female). Median treatment duration of oral treprostinil was 13.1 months. During early therapy (Months 1-5), 62 % (78/126) of patients reported headache and diarrhea, and 40 % (50/126) reported nausea. At Month 6, many patients who reported side effects during early therapy reported an improvement (61 % headache, 44 % diarrhea, 70 % nausea). Common side effect treatments, including acetaminophen, loperamide, and ondansetron, were effective. Approximately one-quarter of patients reporting the most common side effects were untreated at Month 6.

CONCLUSION

Patient selection for, and initiation and titration of, oral treprostinil should be individualized and may include parenteral treprostinil induction-transition for faster titration. Assertive side effect management may help patients reach higher and more efficacious doses of oral treprostinil.

Pharmacological Gq inhibition induces strong pulmonary vasorelaxation and reverses pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening disease with limited survival. Herein, we propose the pharmacological inhibition of Gq proteins as a novel concept to counteract pulmonary vasoconstriction and proliferation/migration of pulmonary artery smooth muscle cells (PASMCs) in PAH. We demonstrate that the specific pan-Gq inhibitor FR900359 (FR) induced a strong vasorelaxation in large and small pulmonary arteries in mouse, pig, and human subjects ex vivo. Vasorelaxation by FR proved at least as potent as the currently used triple therapy. We also provide in vivo evidence that local pulmonary application of FR prevented right ventricular systolic pressure increase in healthy mice as well as in mice suffering from hypoxia (Hx)-induced pulmonary hypertension (PH). In addition, we demonstrate that chronic application of FR prevented and also reversed Sugen (Su)Hx-induced PH in mice. We also demonstrate that Gq inhibition reduces proliferation and migration of PASMCs in vitro. Thus, our work illustrates a dominant role of Gq proteins for pulmonary vasoconstriction as well as remodeling and proposes direct Gq inhibition as a powerful pharmacological strategy in PH.

Molecular recognition and activation of the prostacyclin receptor by anti-pulmonary arterial hypertension drugs

The prostacyclin (PGI2) receptor (IP) is a Gs-coupled receptor associated with blood pressure regulation, allergy, and inflammatory response. It is a main therapeutic target for pulmonary arterial hypertension (PAH) and several other diseases. Here we report cryo-electron microscopy (cryo-EM) structures of the human IP-Gs complex bound with two anti-PAH drugs, treprostinil and MRE-269 (active form of selexipag), at global resolutions of 2.56 and 2.41 angstrom, respectively. These structures revealed distinct features governing IP ligand binding, receptor activation, and G protein coupling. Moreover, comparison of the activated IP structures uncovered the mechanism and key residues that determine the superior selectivity of MRE-269 over treprostinil. Combined with molecular docking and functional studies, our structures provide insight into agonist selectivity, ligand recognition, receptor activation, and G protein coupling. Our results provide a structural template for further improving IP-targeting drugs to reduce off-target activation of prostanoid receptors and adverse effects.

Use of the National Cancer Institute Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events to assess treatment tolerability in pulmonary arterial hypertension: qualitative patient research findings in current and former users of oral selexipag

BACKGROUND

Understanding patients' perspectives regarding drug tolerability, in addition to effectiveness, provides a complete picture of the patient experience and supports more informed therapeutic decision-making. The item library of the National Cancer Institute's Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) was developed to measure patient-reported frequency, severity, and interference of adverse events (AEs) associated with cancer therapies. This qualitative interview study assessed the suitability of items selected from the PRO-CTCAE library for assessing tolerability of selexipag, a medication targeting the prostacyclin pathway for patients with pulmonary arterial hypertension (PAH).

METHODS

Two rounds of 10 qualitative, web-assisted telephone interviews following a semi-structured guide were conducted in individuals with recent experience taking oral selexipag for PAH. Each interview included concept elicitation to gather participants' perspectives on symptomatic AEs (type, frequency, severity, and interference) and cognitive debriefing of PRO-CTCAE items addressing the most frequently reported AEs of oral selexipag.

RESULTS

Interviews were conducted with 20 participants with PAH (mean [range] age 50 [24-68] years; 75% female; 85% in World Health Organization Functional Class II-III), comprising different races/ethnicities, levels of education, and employment status. Fifteen participants were currently treated with selexipag; five had taken selexipag for ≥ 6 months before discontinuing. The most frequently reported AEs included headache, jaw pain, and nausea (n = 15, 12, and 10 participants, respectively). Diarrhea and headache were identified as the most bothersome AEs by 5 and 4 participants, respectively. Some AEs were transitory (e.g., jaw pain); others were long-lasting (e.g., muscle pain). Based on findings from Round 1 interviews, a flushing item was added and the PRO-CTCAE general pain item was modified to be specific to jaw pain for testing in Round 2. Interview findings identified the following AEs as relevant to assess in a PAH clinical trial: nausea, vomiting, diarrhea, flushing, jaw pain, headache, aching muscles, and aching joints.

CONCLUSIONS

The PRO-CTCAE items selected in this study and the additional symptomatic AEs identified as patient-relevant have the potential to be included in assessments capturing the patient perspective on tolerability in future studies of selexipag and possibly other PAH therapies.

Transition from Intravenous Epoprostenol to Treprostinil Due to Intolerable Side Effects in Patients With Pulmonary Arterial Hypertension

Intravenous epoprostenol improves exercise capacity and survival in patients with pulmonary arterial hypertension (PAH); however, it has side effects. Reviewing the side effects associated with epoprostenol and treprostinil is essential for improving the long-term treatment strategies for PAH. This retrospective review included patients with PAH who transitioned from intravenous epoprostenol to intravenous treprostinil owing to intolerable side effects, including high cardiac output symptoms, ascites, and thrombocytopenia. Of the 85 patients who received epoprostenol at our hospital between 2013 and 2021, 16 (11 women), with a median age of 33 (range 26 to 40) years (including 12 with idiopathic PAH, 3 with hereditary PAH, and 1 with connective tissue disease pulmonary hypertension), had to switch from intravenous epoprostenol to treprostinil owing to the side effects. After transitioning, epoprostenol-associated intolerable side effects, such as high cardiac output symptoms, ascites, and thrombocytopenia, were ameliorated. In conclusion, for patients with PAH who have intolerable side effects from epoprostenol and have difficulty in continuing treatment, switching from epoprostenol to treprostinil may be an option. Switching treatment leads to better adherence and improved long-term prostacyclin therapy.

Pulmonary hypertension in hereditary hemorrhagic telangiectasia: A clinical review

Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant hereditary disorder characterized by recurrent spontaneous epistaxis, mucocutaneous telangiectasias, and solid organ arteriovenous malformations (AVMs). Pulmonary hypertension (PH) is an increasingly recognized complication in patients with HHT, most often precipitated by high-output heart failure in the presence of hepatic AVMs as well as pulmonary arterial hypertension in the form of a proliferative vasculopathy. The presence of PH in patients with HHT is associated with significant elevations in rates of morbidity and mortality. Additionally, there is growing recognition of a thromboembolic propensity in this population that increases the risk of chronic thromboembolic PH, posing unique clinical considerations regarding the use of anticoagulation. Patients with HHT are also at risk of PH due to disorders commonly seen in the general population, including left-sided heart and lung disease. The etiology of PH in HHT is multifaceted and complex; the diagnostic approach and treatment strategies must consider the underlying pathophysiology of HHT. This comprehensive review summarizes current knowledge of PH in HHT, detailing the pathogenesis of known etiologies, diagnostic evaluation, and suggested treatment modalities as well as emerging therapies that may be of future interest.

Treprostinil in Neonates with Congenital Diaphragmatic Hernia-Related Pulmonary Hypertension

OBJECTIVE

To describe our experience with treprostinil, evaluate correlations with cardiac function, and assess for adverse effects in neonates with congenital diaphragmatic hernia-related pulmonary hypertension (CDH-PH).

STUDY DESIGN

A retrospective review of a single-center prospective registry at a quaternary care children's hospital. Patients included in the study had CDH-PH treated with treprostinil between April 2013 and September 2021. Assessed outcomes were brain-type natriuretic peptide levels and quantitative echocardiographic parameters collected at baseline, 1 week, 2 weeks, and 1 month after treprostinil initiation. Right ventricular (RV) function was assessed by tricuspid annular plane systolic excursion Z-score and speckle tracking echocardiography (global longitudinal and free wall strain). Septal position and left ventricular (LV) compression were assessed by eccentricity index and M-mode Z-scores.

RESULTS

Fifty-one patients were included, with an average expected/observed lung-to-head ratio of 28.4 ± 9.0%. Most patients required extra-corporeal membrane oxygenation (n = 45, 88%). Survival to hospital discharge was 31/49 (63%). Treprostinil was initiated at a median age of 19 days with a median effective dose of 34 ng/kg/minute. Median baseline brain-type natriuretic peptide level decreased from 416.9 pg/mL to 120.5 pg/mL after 1 month. Treprostinil was associated with improved tricuspid annular plane systolic excursion Z-score, RV global longitudinal strain, RV free wall strain, LV eccentricity index, and LV diastolic and systolic dimensions, reflecting less compression by the RV, regardless of ultimate patient survival. No serious adverse effects were recorded.

CONCLUSIONS

In neonates with CDH-PH, treprostinil administration is well tolerated and is associated with improved RV size and function.

Impact of malnutrition on prognosis in patients with pulmonary arterial hypertension

Pulmonary arterial hypertension is a life-threatening disease that coexists with right heart failure. We evaluated the relationship between malnutrition and prognosis in patients with pulmonary arterial hypertension, as malnutrition is known as a prognosis determinant in chronic heart failure. We retrospectively reviewed data of patients with pulmonary arterial hypertension before treatment. The Geriatric Nutritional Risk Index, Prognostic Nutritional Index, and Controlling Nutritional Status scores on the day of diagnosis were calculated to assess the nutritional status. Clinical endpoints were defined as composite outcomes of all-cause death or lung transplantation. Eighty patients were enrolled (mean age, 50 years; 23 men). The mean pulmonary arterial pressure was 47 ± 19 mmHg, Geriatric Nutritional Risk Index was 99.9 ± 12.0, and Prognostic Nutritional Index was 46.3 ± 10.0. The median Controlling Nutritional Status score was 2 (1-4). During the median 5.5-year follow-up period, 28 composite events occurred. Kaplan-Meier analysis demonstrated significant differences in the incidence of clinical endpoints between groups divided by each median Geriatric Nutritional Risk Index, Prognostic Nutritional Index, and Controlling Nutritional Status score (p = 0.007, 0.039, and 0.010, respectively). In multivariate Cox regression analysis, clinical endpoints were significantly associated with Geriatric Nutritional Risk Index (hazard ratio: 0.953, 95% confidence interval: 0.918-0.990), Prognostic Nutritional Index (hazard ratio: 0.942, 95% confidence interval: 0.892-0.996), and Controlling Nutritional Status score (hazard ratio: 1.230, 95% confidence interval: 1.056-1.433) after adjustment for factors associated in univariate Cox regression analysis. Malnutrition at diagnosis is a useful prognostic predictor for patients with pulmonary arterial hypertension.

Inhaled iloprost is an effective alternative therapy for persistent pulmonary hypertension in newborns

Persistent pulmonary hypertension of the newborn (PPHN) is one of the diseases of the neonate with severe potential morbidity and mortality. Inhaled iloprost, a stable prostacyclin analog, has been suggested as an alternative treatment for inhaled nitric oxide (iNO). However, more data on neonates' dosing, setting, and effectiveness still needs to be solved. This study suggests using inhaled iloprost as rescue therapy for PPHN based on our experience. This was a retrospective study. The data from medical records of six newborns diagnosed with PPHN and had received inhaled iloprost from December 2019 to April 2022 were collected. Demographic and clinical features, dosing regimen, changes in oxygenation index, echocardiographic findings, and mortality were evaluated. The inhalation dose was 2-4 mcg/dose, and 3-48 inhalations per day were applied over 2-7 days. Inhaled iloprost was effective in all patients. No side effects were attributable to inhaled iloprost, and no mortality was recorded. Our experience suggests that inhaled iloprost can be used as a first-line therapy in newborn infants with PPHN when iNO is unavailable. However, there are large fluctuations in the oxygenation index due to the setting.

Cannabidiol (CBD) for the treatment of subcutaneous treprostinil (Remodulin®) site pain: a case report

Background

Pulmonary arterial hypertension occurs as a result of vascular remodeling and dysregulation of endothelial cells that narrows small pulmonary arteries and raises precapillary pressures. Pulmonary arterial hypertension is a rare and progressive disease characterized by dyspnea, chest pain, and syncope. Parenteral treprostinil is indicated for the treatment of pulmonary arterial hypertension to diminish symptoms associated with exercise. Up to 92% of patients treated with treprostinil via subcutaneous delivery experienced infusion site pain and approximately 23% discontinued treatment due to site pain. Cannabidiol salve may have analgesic and anti-inflammatory properties and could be an additional option for patients with infusion site pain.

Case report

Two patients with pulmonary arterial hypertension were treated with cannabidiol salve. Both patients reported a reduction in infusion site pain without the need for narcotics.

Conclusion

These two cases suggest that cannabidiol salve may help to minimize redness and alleviate pain at the infusion site. Additional studies are required to test the effectiveness of cannabidiol in a larger group of patients with infusion site pain.

Incidence of Bloodstream Infection in Patients with Pulmonary Hypertension under Intravenous Epoprostenol or Iloprost—A Multicentre, Retrospective Study

Intravenous synthetic prostacyclin analogs (iPCAs), such as epoprostenol, treprostinil and iloprost have been widely used for the treatment of pulmonary arterial hypertension (PAH). Despite having good outcomes, continuous infusion of iPCAs has been associated with some adverse effects. Bloodstream infection (BSI) is one of the most severe complications, although poorly recognized, especially under iloprost administration, which few studies have addressed. This study aimed to compare the BSI incidence rates between intravenous iloprost and epoprostenol administration. Patients with pulmonary hypertension (PH) functional class III or IV receiving intravenous iloprost or epoprostenol through Hickman catheter, between 2004 and 2019, were retrospectively selected from two PH treatment centers. From a total of 36 patients (13 for iloprost and 23 for epoprostenol), 75% (n = 27) fulfilled the PAH criteria, mainly belonging to the idiopathic group. Overall BSI rate was 1.5/1000 days of treatment (3.38 and 0.09/1000 days for iloprost and epoprostenol, respectively). Patients receiving iloprost were at a higher risk of developing BSI than those receiving epoprostenol (HR: 12.5; 95% CI: 1.569–99.092). A higher mortality rate from BSI was also identified in the iloprost group (p = 0.04). Twenty-seven patients developed BSI, with 92% of them requiring hospitalization. A total of 29 agents were found, 10 Gram-positive (mainly Staphylococcus aureus; n = 5) and 19 Gram-negative (mainly Pseudomonas aeruginosa; n = 6) bacteria. Iloprost administration was linked to a significantly higher incidence of BSI, worse prognosis, and more BSI-related deaths than epoprostenol. BSI due to Gram-negative, commensal, low-virulence bacteria was also higher in the iloprost group. In short, physicians should be aware when prescribing iPCA to guarantee their patients’ safety and best medical care.

Palliative care referrals in patients with pulmonary arterial hypertension: The Pulmonary Hypertension Association Registry

BACKGROUND

Pulmonary arterial hypertension (PAH) is a life limiting disease with substantial symptom burden and healthcare utilization. Palliative care alleviates physical and emotional symptoms for patients with serious illness, and has been underutilized for these patients.

OBJECTIVE

To characterize patients with PAH referred to palliative care and identify predictors of referral.

METHODS

We conducted an observational study of adult patients enrolled in the Pulmonary Hypertension Association Registry from January 2015 through June 2021, performing descriptive statistics on patient characteristics at baseline for all patients and the subset referred to palliative care. These characteristics were modeled in a backwards elimination Cox regression with time to referral to palliative care as the primary outcome.

RESULTS

92 of 1,578 patients were referred to palliative care (5.8%); 43% were referred at their last visit prior to death. Referrals were associated with increasing age per decade (hazard ratio 1.35 [95% confidence interval 1.16-1.58]), lower body mass index (hazard ratio 0.97 [95% confidence interval 0.94-0.998]), supplemental oxygen use (hazard ratio 2.01 [95% confidence interval 1.28-3.16]), parenteral prostanoid use (hazard ratio 2.88 [95% confidence interval 1.84-4.51]), and worse quality of life, measured via lower physical (hazard ratio 0.97 [95% confidence interval 0.95-0.99]) and mental (hazard ratio 0.98 [95% confidence interval 0.96-0.995]) scores on the 12-item Short Form Health Survey.

CONCLUSION

Patients with PAH are infrequently referred to palliative care, even at centers of excellence. Referrals occur in sicker patients with lower quality of life scores, often close to the end of life.

Prediction of Patient Outcomes through Social Determinants of Health: The Pulmonary Hypertension Association Registry (PHAR) Evaluation

Outcomes of patients with pulmonary arterial hypertension (PAH) may be associated with social determinants of health (SDOH) and other baseline patient characteristics. At present, there is no prognostic model to predict important patient outcomes in PAH based on SDOH. Utilizing information from the Pulmonary Hypertension Association Registry (PHAR), we derive a model (PHAR Evaluation or PHARE) to predict an important composite patient outcomes based on SDOH and other patient characteristics. Baseline data regarding SDOH from adult patients with PAH enrolled in the PHAR between 2015 and March 23, 2020, were included for analysis. We performed repeated measures logistic regression modeling with dichotomous outcome data (0 for no events, 1 for one or more events) to derive the PHARE. Here, 1275 consecutive adult patients enrolled in the PHAR from 47 participating centers were included. Variables included in our model are race, gender, ethnicity, household income, level of education, age, body mass index, drug use, alcohol use, marital status, and type of health insurance. Interaction effect between variables was analyzed and several interactions were also included in the PHARE. The PHARE shows a c‐statistic of 0.608 (p < 0.0001) with 95% confidence intervals (0.583, 0.632). Using SDOH and baseline characteristics from the PHAR, the PHARE correlates with our composite patient outcome. Further work evaluating the role of SDOH in prognostic modeling of PAH is indicated.

Real-world practice patterns and characteristics of adverse events with selexipag in Korean patients with pulmonary arterial hypertension

BACKGROUND

Optimizing an individual dose with careful management of adverse events (AEs) is essential in the treatment with selexipag approved for pulmonary arterial hypertension (PAH). This study aims to identify real-world practice patterns and AE characteristics of selexipag.

RESEARCH DESIGN AND METHODS

This multicenter, longitudinal, observational study included Korean patients with PAH who initiated with selexipag and followed up to the earliest timepoint of 24-week post-treatment. The dose-titration pattern, AE incidences by dosing and time course, recovery pattern from AEs, and relationship between doses and AE incidences were evaluated.

RESULTS

Data for 113 patients were included in the analysis. The individual maintenance dose ranged between 200 and 3,200 µg/day. More often AEs were occurred in the titration phase than maintenance phase. There was no significant difference in AE incidences according to the distribution of titration and maintenance doses. The four most common AEs were diarrhea, headache, nausea/vomiting, and myalgia without showing a dose-dependent trend in either frequency or severity. The recovery rates were between 65.0% and 76.9% with a median time to recovery of 15-70 days (range, 2-233).

CONCLUSION

Our finding that AE incidence did not increase with increasing dose of selexipag would provide supportive real-world evidence on the management of optimal dose and safety.

Real‐world dosing characteristics and utilization of parenteral treprostinil in the outpatient setting

Real‐world dosing and titration of parenteral (subcutaneous, SC; intravenous, IV) prostacyclin, a mainstay of pulmonary arterial hypertension (PAH) treatment, is not always consistent with prescribing information or randomized trials and has yet to be adequately characterized. The current study describes real‐world outpatient dosing and titration patterns over time, in PAH patients initiated on SC or IV treprostinil. A longitudinal, cross‐sectional analysis of medication shipment records from US specialty pharmacy services between 2009 and 2018 was conducted to determine dosing and titration patterns of SC or IV treprostinil in the outpatient setting beginning with the patient's first shipment. The sample for analysis included shipment records for 2647 patients (IV = 1040, SC = 1607). Although more patients were started on SC treprostinil than IV, median initial outpatient IV treprostinil dose (11 ng/kg/min at month on therapy one [MOT1]) was consistently and statistically significantly higher than initial outpatient SC dose (7.5 ng/kg/min at MOT1; p < 0.01). However, the SC treprostinil dose acceleration rate (DAR) was more aggressive from MOT1 to MOT6, MOT12, and MOT24, leading to a higher dose achieved at later timepoints. All between‐group DAR differences were statistically significant (p < 0.001). This study provides evidence that real‐world prescribing patterns of parenteral treprostinil in the outpatient setting differs from dosing described in pivotal trials, with important differences between SC and IV administration. Although initial outpatient IV treprostinil dosing was higher, SC titration was accelerated more aggressively and a higher dose was achieved by MOT3 suggesting that factors specific to SC administration (e.g., site pain) may not limit dosing and titration as previously thought.

Update on Medical Management of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension is a rare disease characterized by pulmonary microvasculature remodeling leading to right ventricular failure and death. Medical management of pulmonary hypertension has grown increasingly complex as more therapeutic agents have been developed. Evolving treatment strategies leveraging the endothelin, nitric oxide, and prostacyclin pathways lead to improved exercise capacity and outcomes in patients; however, significant opportunities for advancement remain.

Real-world experience of selexipag titration in pulmonary arterial hypertension

Selexipag is an oral selective prostacyclin-receptor agonist that was approved for use in patients with World Health Organisation (WHO) functional class II-III pulmonary arterial hypertension (PAH). Treatment with individualised doses of selexipag resulted in significant reductions in the composite end point of death or a complication related to PAH in the phase III GRIPHON (Prostacyclin [PGI2] Receptor Agonist In Pulmonary Arterial Hypertension) study. In order to better understand the real-world approach to selexipag titration and to establish the individualised maintenance regimens used in our centre, we performed this retrospective study of the first 20 patients prescribed selexipag. Baseline characteristics differed from the GRIPHON study, with more combination therapy and comorbidities at drug initiation. Maintenance doses were stratified as low-dose in 10% (n=2), medium-dose in 70% (n=14) and high-dose in 20% (n=4). This study highlights that selexipag can be safely initiated, titrated and transitioned in an outpatient setting to achieve an individualised dosing regimen.

Autoimmune hypophysitis as a cause of adrenocorticotropic hormone deficiency in pulmonary arterial hypertension: a case report

Background 

Severe pulmonary arterial hypertension (PAH) is generally treated with multiple PAH-specific vasodilators. If these agents are unsuccessful, additional treatment options are scarce, and the prognosis is poor due to right-sided heart failure. Some of these severe cases are also accompanied by endocrinological side effects. The most common side effect of prostacyclin is thyroid dysfunction, but in very few cases, adrenocorticotropic hormone (ACTH) deficiency may occur.

Case summary 

A 35-year-old woman was diagnosed with hereditary PAH 2 years ago. Since her mean pulmonary arterial pressure was high, combination therapy of vasodilators, including prostacyclin, was introduced. Several months later, she was hospitalized with a persistent fever. Laboratory tests showed no findings suggestive of infection. However, hypereosinophilia and decreased secretion of ACTH and cortisol were noted, which led to the diagnosis of ACTH deficiency. A multimodal diagnostic approach, including pituitary magnetic resonance imaging and axillary lymph node biopsy, indicated that the aetiology of the ACTH deficiency was likely autoimmune hypophysitis. She was treated with hydrocortisone supplementation, which significantly relieved her condition.

Discussion 

Endocrinological side effects in PAH patients using prostacyclin should be carefully addressed. If right-sided heart failure worsens during the administration of prostacyclin, it is essential to determine whether it is due to progression of pulmonary hypertension or endocrinological side effects. Careful diagnosis and treatment are important for managing the haemodynamics and symptoms of PAH patients given prostacyclin.

Pulmonary arterial hypertension in the emergency department: A focus on medication management

Pulmonary arterial hypertension (PAH) is a chronic progressive incurable condition associated with a high degree of morbidity and mortality. With over five drug classes FDA approved in the last decade, the significant advancements in the pharmacologic management of PAH has improved long-term outcomes. Drug therapies have been developed to directly target the underlying pathogenesis of PAH including phosphodiesterase type-5 inhibitors (PDE-5i), endothelin-receptor antagonists (ERAs), guanylyl-cyclase inhibitors, prostacyclin analogues, and prostacyclin receptor agonists. Although these agents offer remarkable benefits, there are significant challenges with their use such as complexities in medication dosing, administration, and adverse effects. Given these consequences, PAH medications are classified as high-risk, and the transitions of care process to and from the hospital setting are a vulnerable area for medication errors in this population. Thus, it is crucial for the emergency department provider to appropriately identify, manage, and triage these patients through close collaboration with a multidisciplinary team to ensure safe and effective medication management for PAH patients in the acute care setting.

Temporarily switching from oral to intravenous selexipag in patients with pulmonary arterial hypertension: safety, tolerability, and pharmacokinetic results from an open-label, phase III study

BACKGROUND

The oral IP receptor agonist selexipag is approved for the long-term treatment of pulmonary arterial hypertension (PAH). Treatment interruptions should be avoided due to the progressive nature of the disease. An intravenous (IV) formulation of selexipag was developed to provide a treatment option for short-term interruptions to oral selexipag. In this prospective, multicenter, open-label study, the safety, tolerability, and pharmacokinetics of temporarily switching between oral and IV selexipag were investigated (NCT03187678, ClinicalTrials.gov).

METHODS

PAH patients receiving stable oral selexipag doses were enrolled. Following three consecutive IV selexipag infusions patients resumed oral selexipag. Corresponding IV and oral doses were selected to achieve comparable exposure to the active metabolite of selexipag. Safety outcomes were monitored throughout, and pharmacokinetic samples were obtained after oral and IV administration.

RESULTS

All 20 patients completed the study. Fifteen patients had adverse events (AEs), most were mild, and none resulted in discontinuation. Headache was the most common AE throughout the study (four patients). Three serious AEs occurred in two patients with underlying comorbidities when oral dosing had resumed. There were no changes in WHO functional class for any patient and no clinically symptomatic changes in blood pressure were observed. Comparable exposure to the active metabolite of selexipag was demonstrated following corresponding oral and IV selexipag doses.

CONCLUSIONS

Temporarily switching between corresponding doses of oral and IV selexipag was well-tolerated with no unexpected safety findings and comparable exposure to the active metabolite. Treatment with IV selexipag is a feasible option to bridge temporary oral selexipag treatment interruptions.

Relationship Between Time From Diagnosis and Morbidity/Mortality in Pulmonary Arterial Hypertension: Results From the Phase III GRIPHON Study

BACKGROUND

Early initiation of pulmonary arterial hypertension (PAH) therapies is associated with improved long-term outcomes, yet data on the early use of prostacyclin pathway agents are limited. In these post hoc analyses of the Prostacyclin (PGI₂) Receptor Agonist In Pulmonary Arterial Hypertension (GRIPHON) study, the largest randomized controlled trial for PAH to date, the prognostic value of time from diagnosis and its impact on treatment response were examined.

RESEARCH QUESTION

How does time from diagnosis impact morbidity/mortality events and response to selexipag treatment in patients with PAH?

STUDY DESIGN AND METHODS

The GRIPHON study randomly assigned 1,156 patients with PAH to selexipag or placebo treatment. Patients were categorized post hoc into a time from diagnosis of ≤ 6 months and > 6 months at randomization. Hazard ratios (selexipag vs placebo) were calculated for the primary end point of morbidity/mortality by time from diagnosis using Cox proportional hazard models.

RESULTS

Time from diagnosis was ≤ 6 months in 34.9% and > 6 months in 65.1% of patients. Time from diagnosis was prognostic of morbidity/mortality, with newly diagnosed patients having a poorer long-term outcome than patients diagnosed for longer. Compared with placebo, selexipag reduced the risk of morbidity/mortality in patients with a time from diagnosis of ≤ 6 months and > 6 months, with a more pronounced effect in newly diagnosed patients (hazard ratio, 0.45 [95% CI, 0.33-0.63] and 0.74 [95% CI, 0.57-0.96], respectively; P = .0219 for interaction).

INTERPRETATION

In the GRIPHON study, newly diagnosed PAH patients had a worse prognosis than patients with a longer time from diagnosis. The benefit of selexipag treatment on disease progression was more pronounced in patients treated earlier than in patients treated later.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01106014; URL: www.clinicaltrials.gov.

Contemporary Pharmacotherapeutic Approach in Pulmonary Arterial Hypertension

Since the 1973 World Symposium on Pulmonary Hypertension, advancements in the understanding of pathophysiology and pathobiology have led to a myriad of pharmacotherapies for the disease. This article journeys through the development of therapeutic approaches for pulmonary arterial hypertension.

Pharmacokinetics and tolerability of LIQ861, a novel dry-powder formulation of treprostinil

A dry-powder inhaled formulation of treprostinil (LIQ861) produced using PRINT® technology offers a substantial advantage over current nebulized therapy. Treprostinil is a synthetic prostacyclin analogue that is currently approved for inhalation administration to patients with pulmonary arterial hypertension via nebulized Tyvaso® inhalation solution. LTI-101 was a phase 1, placebo-controlled, double-blind, randomized, single-center study that evaluated the ascending single-dose pharmacokinetics of LIQ861 in healthy subjects. Six sequential, escalating doses (25, 50, 75, 100, 125, and 150 mcg) were studied to investigate treprostinil exposure from LIQ861 inhalation. Subjects (n = 57) were randomly assigned in a 3:1 ratio to receive a single dose of either LIQ861 (n = 43) or placebo (n = 14); 56 subjects completed all protocol-defined assessments. Following single-dose administration, treprostinil exposure from LIQ861 increased proportionally across the dose range studied, and the pharmacokinetics profile of treprostinil administered as LIQ861 was similar to prior reports of inhaled treprostinil. All doses of LIQ861 were generally well-tolerated with no deaths, serious adverse events, or dose-limiting toxicities. The most frequently reported treatment-emergent adverse events related to study drug administration were coughing and throat irritation, which are common to dry-powder formulations. Treatment-related treatment-emergent adverse events were reported more frequently at higher dose levels; however, all were assessed as mild in severity. We conclude that the pharmacokinetics profile of treprostinil using a dry-powder inhaled formulation increased in proportion to dose as anticipated and was similar to earlier reports of inhaled, nebulized treprostinil (Tyvaso®). Based on these results, a phase 3 study (INSPIRE; Clinicaltrials.gov Identifier NCT03399604) evaluating the long-term safety and tolerability of LIQ861 in patients with pulmonary arterial hypertension was initiated.

Inpatient Initiation of Oral Treprostinil in an Academic Medical System

PURPOSE

Clinicians may transition patients on parenteral or inhaled prostacyclins to oral treprostinil for ease of use or to avoid adverse effects related to parenteral therapy. However, few data are available to guide these transitions in inpatients. The purpose of this analysis is to describe the inpatient initiation of oral treprostinil at an academic medical system.

METHODS

This is a retrospective cohort analysis of patients newly initiated on oral treprostinil at Cleveland Clinic Heath System from 2015 to 2017. Demographic information regarding pulmonary arterial hypertension (PAH) history and previous PAH therapies were recorded. Outcomes evaluated included doses of oral treprostinil utilized, adverse effects related to therapy, and measures of clinical and functional status before and after the initiation of oral treprostinil.

RESULTS

Overall, 29 patients were prescribed oral treprostinil, of which 15 patients were included in the analysis. Common reasons for initiation of oral treprostinil included disease progression (6, 40%) and patient desire (4, 25%). The median duration of transition/initiation of oral treprostinil was 4 days (range, 3-11 days). Median daily dose of oral treprostinil on day 1 of initiation was 2 mg (0.25-4 mg). By day 7, median daily dose was 15 mg (0.75-27.75 mg). Common adverse effects related to therapy were gastrointestinal (7, 47%) and headache (4, 27%). No patients required discontinuation of oral treprostinil due to adverse effects within 90 days of initiation.

CONCLUSION

Inpatient initiation/transition to oral treprostinil was relatively well tolerated. Future studies should evaluate clinical outcomes surrounding the transitioning to oral treprostinil.

Treprostinil Attains Clinically Therapeutic Concentrations in Neonates with Pulmonary Hypertension on Extracorporeal Membrane Oxygenation Support

BACKGROUND

TREPROSTINIL IS A PROSTACYCLIN ANALOG USED FOR TREATMENT OF PULMONARY HYPERTENSION (PH) IN ADULTS AND CHILDREN, CURRENTLY AWAITING CLINICAL ASSESSMENT FOR USE IN NEONATES.: OBJECTIVES: WE AIMED TO INVESTIGATE THE USE OF TREPROSTINIL IN NEONATES WITH PH ON EXTRACORPOREAL MEMBRANE OXYGENATION (ECMO) SUPPORT AND MEASURE PLASMA CONCENTRATIONS OF THE DRUG.: METHODS: THIS IS A RETROSPECTIVE CASE-SERIES WITH PROSPECTIVELY COLLECTED BLOOD SAMPLES, CONDUCTED IN A QUATERNARY CARE NEONATAL INTENSIVE CARE UNIT. BRAIN NATRIURETIC PEPTIDE, CARDIAC FUNCTION ON DOPPLER ECHOCARDIOGRAPHY, AND THE OCCURRENCE OF ADVERSE EFFECTS WAS MONITORED. PLASMA CONCENTRATIONS WERE MEASURED USING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND MASS SPECTROMETRY.: RESULTS: FOUR PATIENTS WITH PH REQUIRING ECMO THERAPY WERE STUDIED. TREPROSTINIL DOSES OF 20-58 NG/KG/MIN REACHED CONCENTRATIONS OF 0.99-4.39 NG/ML AND INDUCED CLINICAL IMPROVEMENT. INFUSION OF TREPROSTINIL WAS ASSOCIATED WITH IMPROVED RIGHT VENTRICULAR FUNCTION, REVERSED RIGHT-TO-LEFT SHUNTING THROUGH THE DUCTUS ARTERIOSUS, AND STABLE OR DECREASING NEED FOR VASOPRESSOR SUPPORT.

NO ADVERSE EFFECTS WERE OBSERVED

CONCLUSIONS: THIS IS THE FIRST STUDY TO REPORT CLINICALLY THERAPEUTIC TREPROSTINIL CONCENTRATIONS IN CIRCULATING PLASMA AFTER TREPROSTINIL ADMINISTRATION IN NEONATES ON ECMO, WITH ASSOCIATED CLINICAL IMPROVEMENT OF PH AND NO SIGNS OF HEMODYNAMIC INSTABILITY.

Cough as an adverse effect on inhalation pharmaceutical products

Cough is an adverse effect that may hinder the delivery of drugs into the lungs. Chemical or mechanical stimulants activate the transient receptor potential in some airway afferent nerves (C-fibres or A-fibres) to trigger cough. Types of inhaler device and drug, dose, excipients and formulation characteristics, including pH, tonicity, aerosol output and particle size may trigger cough by stimulating the cough receptors. Release of inflammatory mediators may increase the sensitivity of the cough receptors to stimulants. The cough-provoking effect of aerosols is enhanced by bronchoconstriction in diseased airways and reduces drug deposition in the target pulmonary regions. In this article, we review the factors by which inhalation products may cause cough.

Rapid transition from oral selexipag to parenteral treprostinil in a patient with mixed-etiology pulmonary hypertension

PURPOSE

Selexipag is an oral nonprostanoid IP prostacyclin receptor agonist that is indicated for treatment of pulmonary arterial hypertension (PAH). In patients with continued symptoms of PAH despite maximized oral therapy with selexipag and other oral therapies, a transition to parenteral prostacyclin may be warranted. There is a paucity of data regarding how to safely transition from oral selexipag to parenteral treprostinil. We describe rapid transition from oral selexipag to parenteral treprostinil in this case report.

SUMMARY

A 65-year-old female with mixed-etiology PAH as result of pulmonary fibrosis related to polymyositis was admitted to the intensive care unit to be transitioned from selexipag to treprostinil due to dyspnea at rest despite therapy with selexipag 1,600 mg twice daily and macitentan 10 mg daily for 3 years. At baseline the patient required oxygen support (4 L/min) at rest to maintain oxygen saturation at or above 90%. Right heart catheterization performed 8 weeks prior to admission revealed severe PAH, with a pulmonary arterial pressure of 73/27 mm Hg and pulmonary vascular resistance of 10 Wood units. On the day of admission the patient was given selexipag 800 µg at 9 am and simultaneously started on intravenous (i.v.) treprostinil at a dose of 2 ng/kg/min. The treprostinil dose was increased by 2 ng/kg/min every 3 hours until a target dose of 22 ng/kg/min was achieved, at which point the patient had experienced dyspnea improvement. She experienced a mild headache and flushing during rapid treprostinil dose escalation. After 30 hours of i.v. treprostinil infusion, the patient was transitioned to subcutaneous treprostinil therapy and discharged.

CONCLUSION

In this case the patient was rapidly transitioned from oral selexipag to i.v. and then subcutaneous treprostinil therapy over a 30-hour period, with minimal adverse effects.

Transitions between infused and oral prostacyclin pathway agents in pulmonary arterial hypertension: key considerations

Prostacyclin pathway agents are a critical treatment for patients with pulmonary arterial hypertension. Seven prostacyclin pathway agents are available, including agents administered by parenteral infusion, by inhalation, and orally. Pulmonary arterial hypertension patients are now transitioned from one prostacyclin pathway agent to another with increasing frequency. Such transitions require careful downtitration and uptitration to avoid decompensation from rapid withdrawal and to achieve a patient's optimal dose based on efficacy and tolerability. Clinical guidance is especially lacking for transitions involving the newer, oral prostacyclin pathway agents; specifically, selexipag and oral treprostinil. We present three case reports of patients with pulmonary arterial hypertension who underwent one or more transition between parenteral and oral prostacyclin pathway agents, including some transitions that were successful and some that were not. These cases illustrate key considerations, such as titration protocols, patient selection, side effect management, and pharmacokinetics.

Pulmonary Arterial Hypertension: A Palliative Medicine Review of the Disease, Its Therapies, and Drug Interactions

Pulmonary arterial hypertension (PAH) is often a progressive and ultimately fatal disease. It is characterized by an elevated mean pulmonary arterial pressure because of disease of the small pulmonary arterioles. PAH leads to a constellation of symptoms, including dyspnea, fatigue, syncope, chest discomfort, and peripheral edema. Disease-targeted therapies for PAH produce symptomatic and functional improvement, but long-term survival remains uncommon without lung transplantation. Palliative care is appropriate to support patients with advanced PAH who typically have a high symptom burden. However, palliative care has historically focused on supporting patients with malignant disease, rather than progressive chronic disease such as PAH. Our aim is to provide palliative care clinicians with a background in the classification, pathophysiology, and modern treatment of PAH. This review describes disease-targeted therapies and their effects on symptoms, physical functioning, and health-related quality of life. We also review the unique physiology of PAH and its implication for palliative interventions. Pharmacological interactions with, and precautions related to commonly used palliative care medications, are discussed.

Pulmonary Arterial Hypertension Emergency Complications and Evaluation: Practical Guide for the Advanced Practice Registered Nurses in the Emergency Department

Pulmonary hypertension (PH) complicates common diseases and can lead to worsening symptoms and increased mortality. A specific group of PH, pulmonary arterial hypertension (PAH), World Health Organization Group 1, may present to the emergency department (ED). We review common ED presentations of patients with PAH such as cardiac arrest/sudden death, right ventricular failure, syncope, hypoxemic respiratory failure, arrhythmias, hemoptysis, pulmonary embolism, chest pain/left main compression syndrome, infection, and considerations for PAH medication administration. We include a case study to illustrate a real example with a positive outcome, and an algorithm for evaluating and triaging patients with PAH in the ED. The ability to recognize, triage, and communicate changes in PAH disease status in a multidisciplinary team approach between the patient, family, specialty pharmacy, and specialized health care providers such as the PH team, is essential for ED providers who are evaluating and treating patients with PAH.

Adverse Events of Prostacyclin Mimetics in Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

Prostacyclin mimetics (PMs) are effective for the treatment of pulmonary arterial hypertension (PAH). However, their clinical use may be limited by their adverse events. This study aims to quantify the different PM adverse events (AEs) with regard to their selectivity towards the prostacyclin (IP) receptor and their administrative routes. The study included randomised, placebo-controlled trials comparing iloprost, beraprost, treprostinil, and selexipag to placebo (published 2002–2016). We report the group efficacy differences between treatment and placebo by weighted and standardised mean difference. The probability of adverse events was determined by the odds ratio (OR). Of the 14 randomised clinical trials involving 3518 PAH patients, outcome and adverse event data were meta-analysed by drug type and route of administration. Prostacyclin mimetics comparison demonstrated a more significant discontinuation of the IP-selective agonist, selexipag, due to an adverse event (OR = 2.2; 95% CI: 1.5, 3.3). Compared to placebo, site pain associated with subcutaneously administered treprostinil was the most significant likely adverse event (OR = 17.5; 95% CI: 11.1, 27.1). Parenteral PMs were associated with fewer adverse effects overall. The overall efficacy of PMs to improve 6-minute walk distance by 16.3 meters was significant (95% CI: 13.0, 19.7). Decreases in pulmonary vascular resistance index (SMD = -5.5; 95% CI: -10.1, -0.9; I² = 98%) and mean pulmonary arterial pressure (SMD = -1.0; 95% CI: -2.6, -0.7; I² = 99%) in treatment groups were found to be significant. Adverse event profiles varied in response to administration route and PM type but were not negated by use of a selective IP agonist. Prostacyclin mimetics exposure to non-target IP receptors may underpin some AEs reported.

Titration of pulmonary arterial hypertension therapeutics: Experience-based recommendations

The availability of new medications has improved exercise capacity, enhanced quality of life, and extended time to clinical worsening in patients with pulmonary arterial hypertension (PAH). For many of these medications, careful individualized dose titration is required to maximize therapeutic effectiveness while minimizing side effects. In addition, specific routes of administration, including intravenous (IV), subcutaneous (SC), and inhaled administration may present additional challenges for patients and healthcare providers. These challenges include the possibility of catheter-related infections (IV), infusion site pain (SC), and adherence to frequent dosing schedules (inhaled). Temporary discontinuations may require re-titration and, in some cases, may even be life threatening. Here, based on our clinical experience, we provide our recommendations for dose titration schemes for PAH medications that require individualized dosing in adult patients, including agents acting on the endothelin-1 pathway (bosentan and ambrisentan), the prostacyclin pathway (epoprostenol, treprostinil, and selexipag), and the nitric oxide pathway (tadalafil and the soluble guanylate cyclase stimulator riociguat). A case study that illustrates the application of best practices for PAH medication dose titration in a real-world setting is presented. Good two-way communication between specialty pharmacies and other healthcare providers promotes optimal medication usage and patient health. Experience has shown that slow, cautious up-titration is generally associated with better long-term outcomes. In all cases, patient education, frequent monitoring and careful management of side effects, and treatment adherence are critical.