Tadalafil improves quality of life and exercise tolerance in idiopathic pulmonary arterial hypertension

The effect of tadalafil on functional capacity and echocardiographic parameters in patients with repaired Tetralogy of Fallot

BACKGROUND

Tetralogy of Fallot (TOF) is one of the most common cyanotic congenital heart diseases (CHD) in children. Various surgical procedures including palliative shunts and TOF total correction (TFTC) were done with some complications, of which, the most common is pulmonary valve regurgitation (PR). Tadalafil is a phosphodiesterase 5 inhibitor which reduces pulmonary vascular resistance, and improves right ventricular function and vascular endothelium, and may have some beneficial effects after TFTC.

METHODS

We studied 18 patients with TOF and PR, with some impaired right ventricular function after TFTC. Tadalafil tablets at a dose of 1 mg per kg (maximum 40 mg) per day as a single dose was administered orally for 8 weeks. In all patients, before and after taking tadalafil, functional class assessment, electrocardiography (ECG) changes, some echocardiographic and endothelial function parameters [flow-mediated dilation (FMD) and intima-media thickness (IMT) of carotid artery], and exercise test were determined.

RESULTS

The patient's mean age was 10.11 ± 4.03 years, and the mean age of operation was 2.52 ± 1.12 years. The effect of tadalafil on different echocardiographic parameters and also on tricuspid valve regurgitation (TR) and PR severity and gradient was not significant. Moreover, it had no effects on QRS duration. Tadalafil had a significant effect on improving FMD and exercise test (P = 0.01). The effect of tadalafil on echocardiographic parameters, carotid artery IMT, and ECG parameters was not significant (P > 0.05). Tadalafil was tolerated well, and the most common side effects were headache and myalgia.

CONCLUSION

This study showed that tadalafil is a safe and well-tolerated drug. It might improve exercise performance, endothelial function, and functional class, and possibly could allow patients a longer period of well-being and could possibly delay the need for pulmonary valve replacement (PVR).

Safety and effectiveness of tadalafil in patients with pulmonary arterial hypertension: Japanese post-marketing surveillance data

OBJECTIVE

To evaluate the long-term safety and effectiveness of tadalafil in patients with pulmonary arterial hypertension (PAH) in real-world clinical practice.

METHODS

This prospective, multicenter, noninterventional, post-marketing surveillance included patients with PAH who were observed for up to 2 years after initiation of tadalafil. Safety was assessed by analyzing the frequency of adverse drug reactions (ADRs), discontinuations due to adverse events (AEs), and serious adverse drug reactions (SADRs). Effectiveness measurements included the assessment of the change in World Health Organization (WHO) functional classification of PAH, 6-minute walk test, cardiac catheterization, and echocardiography.

RESULTS

Among 1676 patients analyzed for safety, the overall incidence of ADRs was 31.2%. The common ADRs (≥1.0%) were headache (7.0%), diarrhea (1.9%), platelet count decreased (1.8%), anemia, epistaxis, and nausea (1.6% each), flushing (1.3%), hepatic function abnormal (1.1%), hot flush, and myalgia (1.0% each). The common SADRs (≥0.3%) were cardiac failure (0.7%), interstitial lung disease, worsening of PAH, and platelet count decreased (0.3% each). Among 1556 patients analyzed for effectiveness, the percentages of patients with improvement of WHO functional class at 3 months, 1 year, and 2 years after the initiation of tadalafil, and last observation were 17.1%, 24.8%, 28.9%, and 22.5%, respectively. At all observation points (except pulmonary regurgitation pressure gradient at end diastole at 3 months), the mean 6-minute walk distance, cardiac catheterization, and echocardiogram measurements showed statistically significant improvement.

CONCLUSION

This surveillance demonstrated that tadalafil has favorable safety and effectiveness profiles for long-term use in patients with PAH in Japan.

Comparing the Efficacy of Tadalafil Versus Placebo on Pulmonary Artery Systolic Pressure and Right Ventricular Function in Patients with Beta-Thalassaemia Intermedia

BACKGROUND

Conventional oral therapies in the management of pulmonary hypertension in people without haemoglobinopathies are of limited value in thalassaemia patients because of toxicity and poor effectiveness. This study was conducted to assess the effect of tadalafil on pulmonary artery pressure and right ventricular systolic function in patients with beta-thalassaemia intermedia.

METHODS

Forty-four patients with beta-thalassaemia intermedia with pulmonary hypertension based on transthoracic echocardiography (TTE) were entered in the study. Patients with hepatic or renal insufficiency and also patients who were treated with organic nitrates or alpha-blockers were excluded. The patients were randomly divided into two groups (n=22) and they were treated for six weeks with tadalafil (40mg daily) or placebo. The pulmonary artery systolic pressure (PASP), tricuspid regurgitation velocity (TRV) and parameters related to systolic function of the right ventricle were measured by the TTE before and after treatment.

RESULTS

Significant improvement in TRV (3.02±0.02 m/s-2.52±0.06 m/s), PASP (45.31±0.66 mmHg-34.26±1.15mmHg) and parameters related to systolic function of the right ventricle were observed in the group who received tadalafil compared to placebo (p< 0.05).

CONCLUSIONS

Tadalafil significantly decreased PASP and TRV in patients with beta-thalassaemia intermedia. Likewise, tadalafil improved right ventricular systolic function in the patients.

Effect of Tadalafil on Myocardial and Endothelial Function and Exercise Performance After Modified Fontan Operation

Better postoperative management of patients who have undergone single ventricle (SV) Fontan procedure could potentially reduce long-term complications and improve the quality of life for patients. The present study determined the effect of tadalafil on myocardial and endothelial function and exercise performance after modified Fontan operation. Patients who had undergone SV modified Fontan operation were enrolled in this clinical trial. The demographic characteristics of the patients were recorded. Before administration of tadalafil and after the trial, ventricular function (MPI, EF, FS, E/A, VTI), exercise performance, and endothelial function were evaluated for sonographic and biochemical markers (FMD, IMT, ICAM, VCAM, NO) using echocardiography, exercise testing, vascular ultrasonography, and biochemical measurements, respectively. A single dose of tadalafil of 1 mg/kg was administered daily for 6 weeks, and the functional class of the patients before and after tadalafil was determined. A total of 15 patients completed this clinical trial. Tadalafil was shown to have a significant effect on myocardial function, exercise performance, and improvement in NYHA functional class (p < 0.05) of study population. It had no significant effect on the biochemical variables and endothelial function except for IMT (p > 0.05), which decreased significantly after tadalafil administration (p < 0.05). The findings indicate that tadalafil is a safe, well-tolerated agent for the use after modified Fontan operation to improve myocardial function and exercise performance and possibly reduce long-term morbidity and mortality of patients. More conclusive results could be obtained from further study with a larger sample size and long-term follow-up.

Clinical utility of tadalafil in the treatment of pulmonary arterial hypertension: an evidence-based review

Pulmonary arterial hypertension (PAH) is a chronic and disabling condition characterized by an elevated pulmonary vascular resistance and an elevated mean pulmonary arterial pressure. Despite recent improvements in treatment availability, PAH remains challenging to treat, burdensome for patients, and ultimately incurable. Tadalafil is a phos-phodiesterase-5 inhibitor that is administered once daily by mouth for the treatment of PAH. Current treatment guidelines recommend tadalafil as an option for patients with World Health Organization functional class II or III PAH. In a placebo-controlled clinical trial, patients taking tadalafil demonstrated significantly improved exercise capacity as measured by the 6-minute walk distance. Patients also experienced decreased incidence of clinical worsening, increased quality of life, and improved cardiopulmonary hemodynamics. Uncontrolled studies and smaller trials have indicated a possible role for tadalafil as a suitable alternative to sildenafil and as a beneficial add-on option when used in combination with other treatments for PAH. Tadalafil is generally safe and well tolerated. Adverse events are typically mild-to-moderate in intensity, and discontinuation rates are usually low. The purpose of this review is to provide an evidence-based evaluation of the clinical utility of tadalafil in the treatment of PAH.

The role of phosphodiesterase inhibitors in the management of pulmonary vascular diseases

Phosphodiesterase inhibitors (PDE) can be used as therapeutic agents for various diseases such as dementia, depression, schizophrenia and erectile dysfunction in men, as well as congestive heart failure, chronic obstructive pulmonary disease, rheumatoid arthritis, other inflammatory diseases, diabetes and various other conditions. In this review we will concentrate on one type of PDE, mainly PDE5 and its role in pulmonary vascular diseases.

Comparison of the therapeutic and side effects of tadalafil and sildenafil in children and adolescents with pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease. In recent years, phosphodiesterase type 5 inhibitors such as sildenafil have been used to treat this disease in children. Recently, tadalafil has been used in adults with similar efficacy but it has been used less often in children. This experimental study was carried out in 18 known patients aged 4-24 years in the Emam Hossein Hospital of Isfahan, Iran. All patients had been taking sildenafil for a few months to years. Patients underwent echocardiographic study, the 6-minute walk test (6MWT), and non-invasive pulse oximetry before and after the 6MWT. These tests were repeated again after sildenafil had been switched to tadalafil for 6 weeks. After 6 weeks of tadalafil prescription, the severity of some of the patients' symptoms decreased, but the New York Heart Association class of the patients did not change more. Mean ± standard deviation (SD) oxygen saturation while taking sildenafil and after 6 weeks of tadalafil were significantly different (p = 0.005). Furthermore, mean ± SD oxygen saturation after the 6MWT while taking sildenafil and after 6 weeks of tadalafil were significantly different (p = 0.036). The mean ± SD distances walked in this test while taking sildenafil and tadalafil were significantly different (p = 0.005). No significant side effects were seen; 15 patients continued tadalafil. Tadalafil may be a safe drug to treat children and young adults with PAH. We did not observe any significant side effects during usage; it improves functional capacity and oxygen saturation better than sildenafil in these patients, and requires fewer daily doses than sildenafil.

Tadalafil as monotherapy and in combination regimens for the treatment of pulmonary arterial hypertension

The purpose of this review is to evaluate the use of tadalafil as monotherapy and in combination regimens for the treatment of pulmonary arterial hypertension (PAH). A systematic English language search of the medical literature using PubMed was conducted between January 1960 and May 2012 using the search terms 'tadalafil', 'therapy', 'pulmonary (arterial) hypertension' and 'combination therapy'. Special emphasis was given to controlled clinical trials and case studies relevant for the use of tadalafil in PAH. The search revealed 113 relevant publications, 31 of which were clinical trials, 52 were reviews and 12 were case reports. Of these, 12 were clinical studies in human patients with PAH who were treated with tadalafil alone, and seven were clinical studies in human patients with PAH who were treated with tadalafil in combination with other agents. Only clinical studies in human patients were included. Exclusion criteria were monotherapy other than using tadalafil and any combination therapy that excluded tadalafil as part of the treatment regimen. Overall, 1353 human subjects were studied; 896 were treated with tadalafil alone while 457 subjects were treated with tadalafil in coadministration. Tadalafil appears to be an effective and a safe treatment option for patients with PAH. It improves clinical status, exercise capacity, hemodynamic parameters, compliance issues and quality of life and reduces the occurrence of clinical worsening. Tadalafil in combination therapy seems to be additive and synergistic in relaxing pulmonary vascular muscle cells but more clinical trials on human subjects are warranted.

The phosphodiesterases type 5 inhibitor tadalafil reduces the activation of the hypothalamus-pituitary-adrenal axis in men during cycle ergometric exercise

Phosphodiesterase type 5 inhibitors may influence human physiology, health, and performance by also modulating endocrine pathways. We evaluated the effects of a 2-day tadalafil administration on adenohypophyseal and adrenal hormone adaptation to exercise in humans. Fourteen healthy males were included in a double-blind crossover trial. Each volunteer randomly received two tablets of placebo or tadalafil (20 mg/day with a 36-h interval) before a maximal exercise was performed. After a 2-wk washout, the volunteers were crossed over. Blood samples were collected at -30 and -15 min and immediately before exercise, immediately after, and during recovery (+15, +30, +60, and +90 min) for adrenocorticotropin (ACTH), β-endorphin, growth hormone (GH), prolactin, cortisol (C), corticosterone, dehydroepiandrosterone-sulfate (DHEAS), and cortisol binding globulin (CBG) assays. C-to-CBG (free cortisol index, FCI) and DHEAS-to-C ratios were calculated. Exercise intensity, perceived exertion rate, O₂ consumption, and CO₂ and blood lactate concentration were evaluated. ACTH, GH, C, corticosterone, and CBG absolute concentrations and/or areas under the curve (AUC) increased after exercise after both placebo and tadalafil. Exercise increased DHEAS only after placebo. Compared with placebo, tadalafil administration reduced the ACTH, C, corticosterone, and FCI responses to exercise and was associated with higher β-endorphin AUC and DHEAS-to-C ratio during recovery, without influencing cardiorespiratory and performance parameters. Tadalafil reduced the activation of the hypothalamus-pituitary-adrenal axis during exercise by probably influencing the brain's nitric oxide- and cGMP-mediated pathways. Further studies are necessary to confirm our results and to identify the involved mechanisms, possible health risks, and potential clinical uses.

A once-daily dose of tadalafil for erectile dysfunction: compliance and efficacy

Selective phosphodiesterase type 5 inhibitors (PDE5Is) have revolutionized the treatment of erectile dysfunction (ED) in men. As an on-demand treatment, PDE5Is have excellent efficacy and safety in the treatment of ED due to a broad spectrum of etiologies. Nevertheless, these drugs do have side-effect profiles that are troublesome to some patients, eg, headache, dyspepsia, myalgia, etc. Furthermore, many patients and their partners dislike the necessity of on-demand treatment for ED, citing a desire for greater spontaneity with sexual interactions. In 2008, approximately 10 years after the release of the first commercially available PDE5I, a paradigm shift in the management of ED occurred with the approval of once-daily dose of tadalafil by the US Food and Drug Administration for the management of ED. The prolonged half-life of tadalafil lends itself well to this dosing regimen and conveys the advantage of separating medication from sexual interactions; lower dose therapy also carries the theoretical benefit of lower incidence of side effects. In this study, we review the current state of the art with respect to this new management strategy for ED, highlighting published reports of the efficacy and tolerability of the daily dose tadalafil regimen.

Long term combination treatment for severe idiopathic pulmonary arterial hypertension

We report the long-term follow-up of 3 cases of severe idiopathic pulmonary arterial hypertension, in whom tadalafil plus sitaxentan combination therapy improved the clinical condition and exercise performance without any relevant adverse event.

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a devastating disease with significant disability and mortality, and it has much higher prevalence than previously thought. During the past 15 years, we have witnessed remarkable advances in our understanding of pathogenesis, in diagnostic process and in the development of disease-specific treatments for PAH. Nowadays, the diagnosis is more clearly defined, non-invasive markers of disease severity can be widely applied, and finally we can adopt evidence-based treatment. Newer drugs availability has resulted in radical change in the management of this disease. The article reviews established approaches to evaluation and treatment of this disorder.

Randomized Placebo-Controlled Crossover Trial of Tadalafil in Raynaud’s Phenomenon Secondary to Systemic Sclerosis

Objective.

Raynaud’s phenomenon (RP) is an important clinical feature of systemic sclerosis (SSc) for which consistently effective therapies are lacking. The study was designed to assess the safety, tolerability, and efficacy of tadalafil, a selective, long acting type V cyclic GMP phosphodiesterase (PDE-5) inhibitor, in this clinical syndrome.

Methods.

We performed a prospective, randomized, double-blind, placebo-controlled, crossover study comparing oral tadalafil at a fixed dose of 20 mg daily for a period of 4 weeks versus placebo in women with RP secondary to SSc.

Results.

Thirty-nine subjects completed the study and were evaluable. There were no statistically significant differences in Raynaud Condition Score (RCS), frequency of RP episodes, or duration of RP episodes between treatment groups. Placebo response was a confounding factor. Tadalafil was well tolerated.

Conclusion.

Tadalafil appears to be safe and well tolerated but lacks efficacy in comparison to placebo as a treatment for RP secondary to SSc.

Erectile dysfunction and heart failure: the role of phosphodiesterase type 5 inhibitors

The phosphodiesterase type 5 (PDE-5) inhibitors are effective in treating erectile dysfunction (ED). ED and heart failure (HF) share similar risk factors, and commonly present together. This association has led to questions ranging from the safety and efficacy of PDE-5 inhibitors in HF patients to a possible role for this class of medication to treat HF patients with or without ED. In addition to endothelial dysfunction, there are causes of ED specific to patients with HF including low exercise tolerance, depression and HF medications. Before treating HF patients with PDE-5 inhibitors, patients should be assessed for their risk of a cardiac event during sexual activity. PDE-5 inhibitors are safe and effective in treating ED in HF patients. An improvement in erectile function by PDE-5 inhibitors was associated with an improvement in quality of life and reduction in depression. Several studies demonstrated the effect of PDE-5 inhibitors on HF per se. PDE-5 inhibitors improved endothelial dysfunction, increased exercise tolerance, decreased pulmonary vascular resistance and pulmonary artery pressure, and increased cardiac index. Several mechanisms whereby PDE-5 inhibitors improve HF have been proposed. PDE-5 inhibitors already have a role in treating primary pulmonary hypertension; however additional studies are needed to determine if they will become a standard therapy for HF patients.

Combination of sitaxentan and tadalafil for idiopathic pulmonary arterial hypertension following relapse on bosentan

Sitaxentan, a highly-selective endothelin receptor antagonist (ETRA) and bosentan a non-selective ETRA are both approved for the treatment of idiopathic pulmonary arterial hypertension (iPAH). Sildenafil is a phosphodiesterase-5 (PDE-5) inhibitor used in the treatment of iPAH. Tadalafil is a long acting PDE-5 inhibitor largely unexplored for the treatment of iPAH. Following failure of monotherapy combination therapy with an ETRA and a PDE-5 inhibitor is often used, a frequently used combination being bosentan with sildenafil. We report our clinical experience in three patients with iPAH treated with a combination of sitaxentan and tadalafil, who previously discontinued bosentan. There was sustained symptomatic and haemodynamic improvement in all three patients treated with the combination. No adverse effect related to the combination treatment was noted. Sitaxentan and tadalafil, both being once a day treatments, can also possibly increase compliance.

Oral phosphodiesterase type 5 inhibitors: nonerectogenic beneficial uses

INTRODUCTION

Phosphodiesterase type 5 (PDE5) hydrolyses cyclic guanylate monophosphate (cGMP) specifically to 5' GMP. PDE5 inhibitors were a breakthrough medication that addressed a previously unfulfilled medical need. They promoted vascular relaxation in the corpora cavernosa and penile erection during sexual stimulation. Sildenafil, vardenafil, and tadalafil were approved then introduced as effective treatments for male erectile dysfunction. This impact has stimulated academic, clinical, and industrial research.

AIM

To highlight the nonerectogenic beneficial uses of oral PDE5 inhibitors.

METHOD

A systematic review of published studies in this affair based on a Pubmed and medical subject heading databases search of all concerned articles.

MAIN OUTCOME MEASURES

Demonstrated beneficial as well as applicable uses of oral PDE5 inhibitors.

RESULTS

As chemical molecules, these drugs were shown to exert potential nonerectogenic beneficial effects. They showed efficacy as a useful adjunct in the management of pulmonary hypertension. Additional uses were extended to different utilities: essential hypertension, benign prostatic hyperplasia, gastrointestinal disorders, endothelial dysfunction, female sexual dysfunction, genital blood flow, exercise capacity, Raynaud's phenomenon, sperm motility, etc.

CONCLUSION

Exploring PDE5 inhibitors for their possible medical applications in diverse specialties seems to be beneficial in making use of these molecules for the welfare of humanity.

Medical therapy for pulmonary arterial hypertension

Recent advances in the understanding of pulmonary arterial hypertension have led to new therapeutic options, although the disease remains incurable and continues to cause substantial morbidity and mortality. Disease-specific therapies have been approved for use in the US, including epoprostenol and its various analogs, endothelin receptor antagonists, and phosphodiesterase 5 inhibitors. The use of combination therapy with agents from more than one of these drug classes is becoming increasingly common, although guidelines establishing optimal combinations are lacking. Meanwhile, potential future therapeutic options are actively being pursued.

Pulmonary arterial hypertension: current therapeutic strategies

The treatment of pulmonary arterial hypertension--once a lethal condition--has evolved considerably over the past few years as the number of therapeutic options available to treat this disease has increased. In this Review we attempt to summarize the current knowledge of the pathogenesis of pulmonary hypertension, in relation to the therapies presently available and those that could become available in the near future. The use of prostacyclin and its analogs, calcium-channel blockers, endothelin-receptor antagonists and phosphodiesterase type 5 inhibitors is reviewed. Newer concepts, such as the use of combination therapy, and the potential for long-term disease amelioration and improvement of outcomes, are also discussed. The role of supportive care and medications not specific to pulmonary hypertension is also examined. In addition, we review the novel emerging therapies, such as imatinib, fasudil, simvastatin, ghrelin and vasoactive intestinal peptide, which hold therapeutic potential for disease modification as well as treatment of symptoms.

The nitric oxide/cGMP signaling pathway in pulmonary hypertension

This article briefly reviews the background of endothelium-dependent vasorelaxation, describes the nitric oxide/cGMP/protein kinase pathway and its role in modulating pulmonary vascular tone and remodeling, and describes three approaches that target the nitric oxide/cGMP pathway in the treatment of patients with pulmonary arterial hypertension.

Tadalafil as an in vitro sperm motility stimulant

Tadalafil (Cialis) is a known oral selective phosphodiesterase-5 inhibitor used widely in the management of erectile dysfunction. To assess its ability on human sperm motility in vitro, 70 asthenozoospermic semen specimens delivered by masturbation were investigated. Semen samples were divided equally into four tubes, one as a control and to the others tadalafil dissolved solution was added in vitro in three different concentrations (4.0, 1.0, 0.5 mg ml(-1) respectively). The tubes were incubated and were followed up for sperm motility per cent changes for 0.5, 1, 2, 3 h. It was found that the concentration used played an important role in the degree of sperm enhancement. Specimens treated with 4 mg ml(-1) tadalafil solution demonstrated a significant decrease in sperm motility compared with the controls. Specimens treated with 1.0 mg ml(-1) solution demonstrated significant increase in sperm progressive forward motility. Specimens treated with 0.5 mg ml(-1) solution demonstrated significant increases in sperm motility but lower than that of 1 mg ml(-1) concentration. It is concluded that in vitro use of tadalafil solution in special concentration has a significant stimulatory effect on asthenozoospermic sperm motility.