Respiratory tract infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first occurred in Wuhan, China, in December 2019 and was declared as a pandemic by WHO. The interaction between the 2019 coronavirus disease (COVID-19) and pulmonary hypertension (PH) in children is not widely known. Phosphodiesterase-5 inhibitors (PDEI), one class of drugs used to treat PH, including sildenafil, can suppress angiotensin type I (AT-1) receptor expression. Furthermore, it reduces proinflammatory cytokines and infiltrates the alveolar, inhibits endothelial and smooth muscle transition, mesenchymal cells in the pulmonary artery, and prevents clotting and thrombosis complications. Sildenafil has shown positive effects by diverting the blood flow to the lungs in such a way that ventilation is adequate and can also be anti-inflammatory.

Introduction: Fetal growth restriction (FGR) is associated with a higher risk of perinatal morbidity and mortality, as well as long-term health issues in newborns. Currently, there is no effective medicine for FGR. Phosphodiesterase-5 (PDE-5) inhibitors have been shown in pre-clinical studies to improve FGR. This study aimed to evaluate the latest evidence about the clinical outcomes and safety of PDE-5 inhibitors for the management of FGR. Methods: Eight databases (PubMed, Embase, Medline, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, Chinese Biomedical Database and WangFang Database) were searched for English and Chinese articles published from the database inception to December 2023. Randomized controlled trials (RCTs) reporting the use of PDE-5 inhibitors in FGR were included. The quality of the RCTs was assessed using the Cochrane Risk of Bias Tool. Odds ratio and mean difference (MD) (95% confidence intervals) were pooled for meta-analysis. Results: From 253 retrieved publications, 16 studies involving 1,492 pregnant women met the inclusion criteria. Only sildenafil (15 RCTs) and tadalafil (1 RCT) were studied for FGR. Compared with the control group (placebo, no treatment, or other medication therapies), sildenafil increased birth weight, pregnancy prolongation and umbilical artery pulsatility indices. However, it also increased the risk of pulmonary hypertension in newborns, as well as headache and flushing/rash in mothers. There were no significant differences in gestation age, perinatal mortality or major neonatal morbidity, stillbirth, neonate death, infants admitted to neonatal intensive care unit, intraventricular hemorrhage and necrotizing enterocolitis in infants, as well as pregnancy hypertension and gastrointestinal side effects in mothers between the treatment and the control groups. Discussion: Sildenafil was the most investigated PDE-5 inhibitors for FGR. Current evidence suggests that sildenafil can improve birth weight and duration of pregnancy but at the same time increase the risk of neonatal pulmonary hypertension. It remains uncertain whether the benefits of sildenafil in FGR outweigh the risks and further high-quality RCTs are warranted. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=325909.

OBJECTIVE: To retrospectively evaluate the incidence rate (IR) of elevated echocardiographic estimated systolic pulmonary artery pressure (sPAP), suspected for pulmonary hypertension (PH), in systemic sclerosis (SSc) patients after the introduction of a combination therapy with bosentan and sildenafil for treatment or prevention of digital ulcers.
METHODS: Patients attending the Scleroderma Unit of the Universital Hospital of Careggi from July 2010 to July 2023 were enrolled. Patients older than 18 years old with a history of digital ulcers, treated with bosentan and sildenafil in combination for at least 12 months, were included. Patients with a diagnosis of PH preceding the introduction of the therapy were excluded. Demographical data, disease duration, laboratoristic, and instrumental data (pulmonary function tests, echocardiographic estimation of sPAP, and ultrasonographic value of renal resistive index) were collected. The IR of echocardiographic signs suspected of pulmonary hypertension and their 95% confidence interval were calculated in events/1000 patients-years.
RESULTS: Thirty-five patients were enrolled; the mean disease duration was 12.82 years (SD 5.92). The mean duration of the combination treatment was 81.03 (SD 43.1.3) months, and the total at-risk time was 2674 months. Two patients (5.7%) presented echocardiographic signs of PH (sPAP 50 mmHg and 40 mmHg); the IR was calculated to be 9/1000 patients-years (95% CI 7.95-10.12). In one of the two patients, right heart catheterism (RHC) excluded PAH, while the other patient refused to undergo RHC, and PAH could not be confirmed/excluded. The stability of PFTs and echocardiographic sPAP was observed during the observation time.
CONCLUSIONS: The results of this retrospective study suggest that combination therapy with endothelin receptor antagonists and phosphodiesterase-5 (PDE5) inhibitors could help in preventing PAH in SSc; prospective case-control studies on a larger population are needed to improve knowledge in this field.

Capsule phase microextraction (CPME) is an efficient bioanalytical technique that streamlines the sample preparation by integrating the filtration and stirring mechanism directly into the device. A novel composite sorbent designed to be selective towards the target analytes consisting of mixed-mode sorbent chemistry synthesized by sol-gel technology is found promising and superior to the conventional C18 sorbents. Herein we describe the encapsulation of an ionic liquid (IL)/Carbowax 20M-functionalized sol-gel sorbent (sol-gel IL/Carbowax 20 M) in the lumen of porous polypropylene tubes for the capsule phase microextraction of three phosphodiesterase-5 inhibitors namely avanafil, sildenafil, and tadalafil in human serum and urine samples. The CPME device was characterized by Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FT-IR). The experimental parameters of CPME procedure (e.g. sample pH and ionic strength, extraction time, stirring rate, elution solvent and volume) were carefully optimized to achieve the highest possible extraction efficiency for the analytes. Method validation was conducted in terms of precision, linearity, accuracy, matrix effect, lower limits of quantification, and limits of detection (LOD). The method linearity was investigated in the range of 50-1000 ng mL-1 for all analytes while the precision was less than 11.8 % in all cases. For all analytes, the LOD values were 17 ng mL-1. The IL/CW 20M-functionalized microextraction capsules could be reused at least 25 times both for urine and serum samples. The green character and the applicability of the proposed method were evaluated using the ComplexGAPI and BAGI indexes. The optimized CPME protocol exhibited reduced consumption of organic solvent and generation of waste, cost-effectiveness, and simplicity. Finally, the proposed method was successfully applied to the analysis of sildenafil in human urine after administration of drug-containing formulation.

Pharmacoepidemiologic studies using routinely collected data allow researchers to propose drugs for repurposing trials for dementia prevention or treatment. A recent cohort study reported a 54% lower dementia risk among users of sildenafil compared to users of certain cardiovascular medications. We caution that \"confounding by indication\" can arise when outcomes are compared between a drug of interest and an inappropriate comparator. Here, we emphasize important considerations in selecting an active comparator. We assess the implications of substantial risk of confounding by indication in pharmacoepidemiologic studies linking phosphodiesterase-5 inhibitors to lower dementia risk.

BACKGROUND: Biological and scarce epidemiological evidence suggested that phosphodiesterase-5 inhibitors (PDE5i) might reduce dementia risk. We aimed to examine the association between PDE5i and dementia using real-world data.
METHODS: Two retrospective cohorts within the database of Clalit, the largest healthcare provider in Israel (2005-2023), were studied. The first cohort included new daily users, older than 50 years of age, of low-dose tadalafil, prescribed for benign prostatic hypertrophy (BPH), propensity-score matched to new-users of alpha-1 blockers, and analyzed using 2-year lag time. The second cohort included patients with erectile dysfunction, with/without any PDE5i treatment, using time-dependent analysis. Individuals in the cohorts were followed through May 2023 for the occurrence of dementia.
RESULTS: The first cohort included 5,204 tadalafil initiators propensity-score matched to 18,565 alpha-1 blockers initiators. There was no association between tadalafil use and dementia risk, HR = 0.99 (95% CI: 0.88-1.12), p = 0.927. Similar results were obtained in a competing risk analysis, and in a sensitivity analysis in which we restricted the cohort to patients older than 60 years at cohort entry. The second cohort of 133,336 patients with erectile dysfunction included new users and nonusers of any PDE5i. In a mean follow-up of 7.9 years, 8,631 patients were newly diagnosed with dementia. In a time-dependent multivariable analysis, PDE5i use was not associated with reduced dementia risk, HR = 0.95 (95% CI: 0.86-1.04). Results were not changed in sensitivity analyses (patients older than 60 years or stratification by PDE5i type).
CONCLUSIONS: This study suggests that the use of PDE5 inhibitors is not associated with decreased risk of dementia.

In Riociguat rEplacing PDE5i therapy evaLuated Against Continued PDE5i thErapy (REPLACE) (NCT02891850), improvements in risk status were observed in patients with pulmonary arterial hypertension (PAH) at intermediate risk switching to riociguat versus continuing phosphodiesterase-5 inhibitors (PDE5i). This post hoc study applied the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) Lite 2 and Comparative Prospective Registry of Newly Initiated Therapies for Pulmonary (COMPERA) 2.0 risk-assessment tools to REPLACE to investigate the impact of baseline risk status on clinical improvement. The proportions of riociguat- and PDE5i-treated patients achieving the primary end-point at REVEAL Lite 2 low, intermediate, and high baseline risk reflected the overall population. Proportions of riociguat-treated patients achieving the primary end-point were comparable between the COMPERA 2.0 intermediate-low risk (39%) and intermediate-high risk (43%) groups. Our findings show that patients in REPLACE achieved clinical improvement by switching from PDE5i to riociguat across all COMPERA 2.0 and most REVEAL Lite 2 baseline risk strata.

UNASSIGNED: Our study aims to characterize the ocular safety profiles of phosphodiesterase type 5 (PDE5) inhibitors and explore the differences among different PDE5 inhibitors.
UNASSIGNED: We analyzed reports on ocular adverse events associated with sildenafil, vardenafil and tadalafil submitted to the FDA Adverse Event Reporting System (FAERS) database from the first quarter of 2004 to the first quarter of 2023. Disproportionality analysis was conducted to evaluate reporting risk profiles.
UNASSIGNED: Among 61,211 reports qualifying for analysis, 5,127 involved sildenafil, 832 vardenafil, and 3,733 tadalafil. All PDE5 inhibitors showed increased reporting odds ratios (ROR) for ocular adverse events, with vardenafil highest (ROR 4.47) followed by sildenafil and tadalafil. Key ocular adverse events included cyanopsia, optic ischemic neuropathy, visual field defects, unilateral blindness and blindness. Sildenafil showed the highest disproportionality for cyanopsia (ROR 1148.11) while vardenafil and tadalafil showed the highest disproportionality for optic ischemic neuropathy. Time-to-onset analysis also revealed significant differences, with sildenafil having a later median time-to-onset compared to vardenafil and tadalafil.
UNASSIGNED: This comprehensive pharmacovigilance study reveals distinct patterns of ocular adverse events associated with PDE5 inhibitors. These findings contribute to a better understanding of the safety profiles of PDE5 inhibitors and may guide healthcare professionals in clinical decision-making.

This review focuses on Pulmonary Alveolar Microlithiasis (PAM), an autosomal recessive genetic disorder characterized by calcium crystal deposits (microliths) resulting from loss of function of the SLC34A2 gene. PAM is a rare disease with approximately 1100 reported cases globally. The historical context of its discovery and the genetic, epidemiological, and pathophysiological aspects are discussed. PAM falls under interstitial lung diseases and is associated with pulmonary hypertension (PH), primarily categorized as Group 3 PH. The clinical manifestations, diagnostic approaches, and challenging aspects of treatment are explored. A clinical case of PAM with severe pulmonary hypertension is presented, emphasizing the importance of comprehensive evaluation and the potential benefits of phosphodiesterase-5 inhibitors (PDE5i) therapy. Despite limited therapeutic options and challenging diagnosis, this review sheds light on recent developments and emerging treatments for PAM and associated pulmonary hypertension.

The treatment with phosphodiesterase-5 (PDE-5) inhibitors was postulated in heart failure (HF). We conducted a systematic review and a meta-analysis on their beneficial and adverse effects in patients with HF.
A meta-analysis of randomized trials evaluating the chronic use of PDE-5 inhibitors in patients with HF was conducted. Endpoints included death, HF hospitalizations, functional capacity, pulmonary pressures, quality of life, and adverse effects. Random-effects models were used to pool outcomes. Categorical data were summarized with relative risks (RR) and 95% confidence intervals (95%CI), and continuous data with weighted mean differences and standardized mean differences.
Sixteen studies (1119 participants) were included. No effect was observed on mortality (RR: 1.16; 95%CI: 0.50-2.66; I2: 0.0%) or HF hospitalizations (RR: 0.75; 95%CI: 0.41-1.37; I2: 38.7%). Treatment significantly reduced pulmonary systolic pressure (-10.64 mmHg; 95%CI: -5.14 to -16.15 mmHg; I2: 96.0%), and increased peak oxygen consumption (2.06 ml/kg/min; 95%CI: 0.40-3.72; I2: 89.6%), although with high inconsistency. There were no significant effects on quality of life (-0.15; 95%CI: -0.48-0.18; I2: 0.0%). On the other hand, the risk of headaches was increased (RR: 1.63; 95%CI: 1.11-2.39; I2: 0.0%). Publication bias was identified for HF hospitalizations.
Current data suggest that PDE-5 inhibitors therapy does not improve prognosis or quality of life among HF patients. Hemodynamic and functional effects could be relevant, and more studies are necessary to define its role.
El tratamiento con inhibidores de la fosfodiesterasa 5 (iFDE-5) fue postulado en la insuficiencia cardiaca (IC). Se realizó una revisión sistemática y metaanálisis sobre sus efectos beneficiosos y adversos en pacientes con IC.
Metaanálisis de ensayos clínicos aleatorizados que evaluaron el uso crónico de iFDE-5 en pacientes con IC. Los criterios de valoración finales incluyeron la muerte, las hospitalizaciones por IC, la capacidad funcional, las presiones y las resistencias pulmonares, la calidad de vida y los efectos adversos. Se utilizaron modelos de efectos aleatorios para agrupar los resultados. Los datos categóricos fueron resumidos como riesgos relativos (RR) e intervalos de confianza del 95% (IC95%), y los datos continuos como diferencias de medias ponderadas y diferencias de medias estandarizadas.
Se incluyeron 16 estudios (1119 participantes). No se observaron efectos sobre la mortalidad (RR: 1,16; IC95%: 0.50-2.66; I2: 0.0%) ni sobre las hospitalizaciones por IC (RR: 0,75; IC95%: 0.41-1.37; I2: 38.7%). El tratamiento redujo significativamente la presión sistólica pulmonar (−10,64 mmHg; IC95%: −5.14 a −16.15 mmHg; I2: 96.0%) e incrementó el consumo máximo de oxígeno (2.06 ml/kg/min; IC95%: 0.40-3.72 ml/kg/min; I2: 89.6%), aunque con elevada inconsistencia. No se detectaron efectos significativos sobre la calidad de vida (−0.15; IC95%: −0.48-0.18; I2: 0.0%). Por otra parte, aumentó el riesgo de cefaleas (RR: 1.63; IC95%: 1.11-2.39; I2: 0.0%). Se identificó un sesgo de publicación para las hospitalizaciones por IC.
Los datos actuales sugieren que el tratamiento con iFDE-5 no mejora el pronóstico ni la calidad de vida de los pacientes con IC. Los efectos hemodinámicos y funcionales podrían ser relevantes, y son necesarios más estudios para definir su rol.