Sildenafil/Viagra in the treatment of premature ejaculation

An overview of conventional and investigational phosphodiesterase 5 inhibitors for treating erectile dysfunction and other conditions

INTRODUCTION

There is a rising concern about developing innovative, efficacious PDE5I molecules that provide better safety, efficacy and tolerability with less adverse effects. Innovative PDE5I with dual targets have also been defined in the literature. Additionally, some of PDE5I are able to selectively inhibit other enzymes such as histone deacetylase, acetylcholine esterase, cyclooxygenase or act as nitric oxide donors. This review presents knowledge concerning the advanced trends and perspectives in using PDE5I in treatment of ED and other conditions.

AREAS COVERED

Pre-clinical and early clinical trials that investigated safety, efficacy and tolerability of novel PDE5I such as Udenafil, Mirodenafil, Lodenafil, Youkenafil, Celecoxib and TPN729 in treatment of ED and other conditions.

EXPERT OPINION

Preclinical and limited early clinical studies of the new molecules of PDE5I have demonstrated encouraging results however, safety, efficacy, and tolerability are still an issue that necessitate further long-term multicenter clinical studies to ensure justification of their uses in treatment of ED and other conditions.Progress in molecular delivery techniques and tailored patient-specific management and additional therapeutic technology will dramatically improve care for ED and other conditions. The dream of ED and many other conditions becoming more effectively managed may be feasible in the near future.

The Construction and Application of a New Screening Method for Phosphodiesterase Inhibitors

Phosphodiesterases (PDEs), a superfamily of enzymes that hydrolyze cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), are recognized as a therapeutic target for various diseases. However, the current screening methods for PDE inhibitors usually experience problems due to complex operations and/or high costs, which are not conducive to drug development in respect of this target. In this study, a new method for screening PDE inhibitors based on GloSensor technology was successfully established and applied, resulting in the discovery of several novel compounds of different structural types with PDE inhibitory activity. Compared with traditional screening methods, this method is low-cost, capable of dynamically detecting changes in substrate concentration in live cells, and can be used to preliminarily determine the type of PDEs affected by the detected active compounds, making it more suitable for high-throughput screening for PDE inhibitors.

Development and evaluation of sildenafil/glycyrrhizin-loaded nanofibers as a potential novel buccal delivery system for erectile dysfunction

Erectile dysfunction (ED) is a growing health condition that needs safe and effective therapy. One of the main common treatments is sildenafil which is used in clinics for managing erectile dysfunction by enhancing the blood supply to the penis. In the current study, sildenafil was formulated as nanofibers and mixed with the root extract of Glycyrrhiza glabra (glycyrrhizin) as a natural sweetener to be administrated in the buccal cavity for enhanced drug bioavailability, rapid drug absorption and improved patient compliance. The formulated dual-loaded nanofibers were evaluated by measuring diameter, disintegration, drug loading efficiency, drug release profile, and in vitro cell viability assessment. The results showed that the sildenafil/glycyrrhizin-loaded fibers had a diameter of 0.719 ± 0.177 μm and lacked any beads and pores formation on their surfaces. The drug loading and encapsulation efficiency for sildenafil were measured as 52 ± 7 µg/mg and 67 ± 9 %, respectively, while they were 290 ± 32 μg/mg and 94 ± 10 %, respectively, for glycyrrhizin. The release rate of sildenafil and glycyrrhizin demonstrated a burst release in the first minute, followed by a gradual increment until a complete release after 120 min. The in vitro cell viability evaluation exhibited that the application of sildenafil and glycyrrhizin is safe upon 24-hour treatment on human skin fibroblast cells at all used concentrations (i.e., ≤ 1,000 and 4,000 μg/mL, respectively). However, the application of sildenafil-glycyrrhizin combination (in a ratio of 1:4) demonstrated more than 80 % cell viability at concentrations of ≤ 250 and 1000 μg/mL, respectively, following 24-hour cell exposure. Therefore, sildenafil/glycyrrhizin dual-loaded PVP nanofibers showed a potential buccal therapeutic approach for erectile dysfunction management.

Utilization Trends of Phosphodiesterase Type-5 Inhibitors for Erectile Dysfunction Between 2019 and 2023 in Tanzania

Introduction Erectile dysfunction (ED) profoundly affects millions of people globally, including interfering with mental health and quality of life. Phosphodiesterase type-5 inhibitors (PDE5Is) such as sildenafil are pivotal in ED treatment. This study aimed to examine the utilization patterns of PDE5Is in Tanzania. Materials and methods In this retrospective longitudinal study, data on sildenafil and other similar PDE5Is imported between 2019 and 2023 were sourced from the Tanzania Medicines and Medical Devices Authority (TMDA). Pre-processing and visualization were performed using Microsoft Power BI Desktop, and further analysis was performed using IBM SPSS Statistics for Windows, Version 26 (Released 2019; IBM Corp., Armonk, New York, United States). Utilization trends were ascertained through curve fitting, Holt's linear trend model, and autoregressive integrated moving average (ARIMA) models. The defined daily doses (DDDS) per 1000 inhabitants (DID) were calculated using the World Health Organization (WHO) Anatomical Therapeutic Chemical (ATC) Classification System and the DDD methodology endorsed by the WHO Collaborating Centre for Drug Statistics Methodology. Results Between 2019 and 2023, there was a pronounced increase in the importation of approximately 587 consignments of PDE5Is. Employing the Holt model (R-square = 0.843), a substantial increase from 0.220910 DID in 2019 to 0.534272 DID by 2025 was observed and anticipated. The period witnessed sildenafil dominating 75.5% of the total use, with Erecto being the most consumed brand (37.6% of total DID). Notably, 2022 had the highest surge (27.2% of the total), albeit a slight decline was observed in 2023 (20.5%). This trend was supported by a linear regression model (R-square = 0.889). Conclusion We found increasing annual trends of PDE5Is of utilization. This requires critical oversight and effective policies to ensure appropriate use and risk minimization.

Exploring the application of sildenafil for high-fat diet-induced erectile dysfunction based on interleukin-18-mediated NLRP3/Caspase-1 signaling pathway

Background

Inflammation is a key risk factor for heart disease and has also been linked to erectile dysfunction (ED). Sildenafil is a phosphodiesterase type 5 inhibitor with a strong antioxidant effect. Interleukin (IL)-18 is a proinflammatory factor. Excessive production and release of IL-18 disrupt the balance between IL-18 and IL-18 binding proteins in certain inflammatory diseases, leading to the occurrence of pathological inflammation.

Aim

We evaluated the effects of sildenafil on erectile function in a rat model of high-fat diet-induced ED.

Methods

Male Sprague Dawley rats (6 weeks old) were divided into 5 groups: control, ED, sildenafil, IL-18, and IL-18 + sildenafil. Subsequently, intracavernous pressure and mean arterial pressure were used to assess the erectile function of these rats. The expression of endothelial nitric oxide synthase, pyroptosis factors, and the ratio of smooth muscle cells and collagen fibers were evaluated in the serum and corpora tissue.

Outcomes

Exploring the role and mechanism of sildenafil in ED through NLRP3-mediated pyroptosis pathway.

Results

In comparison to the ED and IL-18 groups, there were statistically significant increases in the ratio of intracavernous pressure to mean arterial pressure, endothelial nitric oxide synthase expression, and the ratio of smooth muscle cells to collagen fibers following sildenafil intervention (P < .05). The sildenafil group and IL-18 + sildenafil group also showed statistically significant decreases the expression of NLRP3, caspase-1, and gasdermin D (P < .05).

Clinical Implications

Sildenafil can improve erectile dysfunction by inhibiting inflammation.

Strengths and Limitations

Strengths are that the relationship between pyroptosis and ED has been verified through in vitro and in vivo experiments. The limitation is that the conclusions drawn from animal and cells experiments need to be confirmed in clinical research.

Conclusion

Sildenafil may reduce the effect of IL-18-induced inflammation in high-fat diet-induced ED rats through NLRP3/caspase-1 pyroptosis pathway.

The effects of sildenafil citrate on intrauterine growth restriction: a systematic review and meta-analysis

BACKGROUND

An increase in vascular resistance of uterine vessels is associated with intrauterine growth restriction (IUGR). Sildenafil citrate, a phosphodiesterase-5 inhibitor that stabilizes cyclic guanosine monophosphate (cGMP) and increases nitric oxide levels, improves placental perfusion by dilation of spiral arteries and is beneficial in managing IUGR. This study aims to determine the effectiveness of sildenafil citrate in improving perinatal outcomes in IUGR pregnancies.

METHODS

Meta-analysis was performed on data extracted from all studies specific to sildenafil citrate in IUGR management, searching relevant articles on PubMed, Medline, Google Scholar, Embase, and Cochrane databases. Publications identified by the manual search, based on references in reviews, were also included. Dichotomous results were presented as risk ratio (95% confidence interval), while continuous results were expressed as mean difference (MD); samples represented by the random effects model.

RESULTS

Nine trials were included where the sildenafil citrate effect was compared with a placebo or no intervention. A significant increase in birth weight [SMD (95% CI), 0.69 (0.31, 1.07)] was seen in IUGR pregnancies managed with sildenafil. However, gestational age (SMD (95% CI), 0.44 (-0.05, 0.94], fetal death rate [RR (95% CI), 0.56 (0.17, 1.79)] in IUGR pregnancies was not changed by sildenafil. Neonatal death [RR (95% CI), 0.93 (0.47, 1.86)] and neonatal intensive care unit (NICU) admissions [RR (95% CI), 0.76 (0.50, 1.17)] were not significantly different between sildenafil and control groups.

CONCLUSION

Sildenafil citrate increases birth weight and prolonged pregnancies but did not affect stillbirth rate, neonatal death, and NICU admission.

TRIAL REGISTRATION

The study was registered in PROSPERO on September 18, 2021 (CRD42021271992).

Phosphodiesterase type 5 inhibitors and premature ejaculation: an overview of systematic reviews/meta-analyses using the AMSTAR 2, ROBIS, and GRADE tools

Introduction

The place of phosphodiesterase type 5 inhibitors (PDE5-Is) in treating premature ejaculation (PE) remains a therapeutic challenge.

Objectives

(1) To summarize the evidence of the efficacy and safety of PDE5-Is from published systematic reviews/meta-analyses (SRs/MAs). (2) To evaluate the reporting, methodological quality, and evidence quality of SRs/MAs concerning PE.

Methods

Nine databases were searched to retrieve SRs/MAs on using PDE5-Is for PE from inception to July 2022. Methodological quality and risk of bias were assessed with the AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) and ROBIS (Risk of Bias in Systematic Reviews). GRADE criteria (Grading of Recommendations, Assessment, Development, and Evaluations) were used to assess the evidence quality.

Results

The literature search revealed 15 relevant SRs/MAs covering 28 primary studies (9 pairwise MAs and 6 network MAs) rated as low or very low quality and high risk of bias except 1 review that was rated as moderate quality and low risk of bias. Among the 27 outcome measures related to efficacy and safety, the quality of evidence according to GRADE criteria was low in 4 and critically low in 23. Oral PDE5-Is have demonstrated a possible benefit over placebo in lifelong PE and mixed PE. The results of pairwise and network MAs advocated that the combined use of PDE5-Is and SSRIs is of possible benefit as compared with either SSRIs or PDE5-Is alone. The total adverse effects were more frequent with PDE5-Is than placebo.

Conclusion

PDE5-Is are of a possible benefit than placebo in lifelong PE and mixed PE. The results favor coadministration of PDE5-Is plus SSRIs over SSRIs alone or PDE5-I monotherapy. These conclusions should be interpreted cautiously due to the low methodological quality and low quality of evidence of most available reviews. Additional higher-quality randomized controlled trials, SRs, and MAs are warranted to provide a better estimate of any effect size.

Selective serotonin reuptake inhibitors combined with traditional Chinese medicine for premature ejaculation: A systematic review and meta-analysis

BACKGROUND

Premature ejaculation (PE) is still a tough problem in drug treatment. Many clinical trials have proven that traditional Chinese medicine (TCM) has a significant effect in the treatment of PE. This article aims to provide the latest evidence for the efficacy and safety of TCM combined with selective serotonin reuptake inhibitors (SSRIs) in the treatment of PE.

METHODS

We looked for randomized controlled trials (RCTs) from China National Knowledge Infrastructure, Wanfang, VIP Database, MEDLINE, PubMed, Web of Science, EMBASE, and Cochrane Library until June 30, 2022. STATA 15.1 software was used to analyze all data for this article. The quality of the included articles was evaluated using the Cochrane Reviewer's Handbook 5.3.

RESULTS

Finally, we selected 16 high-quality RCTs in our meta-analysis, which containing 889 patients. Meta-analysis suggested that, compared with SSRIs alone, combination of TCM with SSRIs increased significantly intravaginal ejaculation latencv time and the scores of ejaculation control ability, sexual life satisfaction, PE-related distress, and communication difficulties between partners related to PE. Also, there was no significant difference in adverse effects between the two groups. In addition, the results of publication bias test showed that no significant bias occurred.

CONCLUSION

The combined use of TCM and SSRIs has significant effect in the treatment of PE compared with SSRIs monotherapy and was generally well tolerated. Due to the small sample size, multicenter and large sample RCT is still needed in the future to further confirm the effectiveness and safety of TCM combined with SSRIs in the treatment of PE.

Current and emerging treatment options for premature ejaculation

Premature ejaculation (PE) is a prevalent male sexual dysfunction. Current standard treatment regimens include behavioural therapies, topical anaesthetics, dapoxetine and other selective serotonin reuptake inhibitors (SSRIs). Most of the pharmacotherapeutic options target neurotransmitters (such as serotonin and oxytocin) that have a role in the ejaculation mechanism. However, these treatments are mildly effective and only provide a temporary delay in the ejaculation latency time, and PE recurs when the treatment is stopped. Thus, a treatment for PE is urgently needed and research is ongoing to find the ideal PE therapy. The efficacy and safety of topical anaesthetics and SSRIs in delaying ejaculation have been confirmed in many well-designed controlled trials. Both preclinical and clinical studies on new-generation SSRIs are ongoing. Moreover, promising results came from clinical trials in which the efficacy of on-demand PE therapies targeting neurotransmitters other than serotonin, such as α1-adrenoceptor antagonists and oxytocin antagonists, was assessed. Surgical intervention and neuromodulation have been proposed as potential treatment options for PE; however, current PE guidelines do not recommend these treatments owing to safety concerns.

The NO/cGMP/PKG pathway in platelets: The therapeutic potential of PDE5 inhibitors in platelet disorders

Platelets are the "guardians" of the blood circulatory system. At sites of vessel injury, they ensure hemostasis and promote immunity and vessel repair. However, their uncontrolled activation is one of the main drivers of thrombosis. To keep circulating platelets in a quiescent state, the endothelium releases platelet antagonists including nitric oxide (NO) that acts by stimulating the intracellular receptor guanylyl cyclase (GC). The latter produces the second messenger cyclic guanosine-3',5'-monophosphate (cGMP) that inhibits platelet activation by stimulating protein kinase G, which phosphorylates hundreds of intracellular targets. Intracellular cGMP pools are tightly regulated by a fine balance between GC and phosphodiesterases (PDEs) that are responsible for the hydrolysis of cyclic nucleotides. Phosphodiesterase type 5 (PDE5) is a cGMP-specific PDE, broadly expressed in most tissues in humans and rodents. In clinical practice, PDE5 inhibitors (PDE5i) are used as first-line therapy for erectile dysfunction, pulmonary artery hypertension, and lower urinary tract symptoms. However, several studies have shown that PDE5i may ameliorate the outcome of various other conditions, like heart failure and stroke. Interestingly, NO donors and cGMP analogs increase the capacity of anti-platelet drugs targeting the purinergic receptor type Y, subtype 12 (P2Y12) receptor to block platelet aggregation, and preclinical studies have shown that PDE5i inhibits platelet functions. This review summarizes the molecular mechanisms underlying the effect of PDE5i on platelet activation and aggregation focusing on the therapeutic potential of PDE5i in platelet disorders, and the outcomes of a combined therapy with PDE5i and NO donors to inhibit platelet activation.

Case Report: Central retinal artery occlusion following sildenafil intake

Purpose: To report a case of central retinal artery occlusion associated with sildenafil intake and briefly discuss its causative pathogenesis. Methods: A 50-year-old man with no premorbidities presented with symptoms of sudden severe visual field constriction in the left eye (LE). Best-corrected visual acuity in the LE was 20/25. Fundus examination and fluorescein angiography of the LE were suggestive of central retinal artery occlusion (CRAO) with cilioretinal artery sparing. Further investigation revealed that 100 mg of sildenafil had been taken for the first time three hours before the onset of symptoms. Results: The patient was treated promptly with intravenous acetazolamide, sublingual isosorbide dinitrate and ocular massage, but without visual recovery. No other associated systemic or local risk factors were found, and the case was classified as a potential complication of sildenafil. Conclusion: Although no direct link could be established, the aim of this report is to highlight the incidence and to consider this issue when evaluating any case of central retinal artery occlusion.

Psychosis beas a rare side effect of sildenafil: a case report

BACKGROUND

Sildenafil citrate is a commonly used medication for the management of erectile dysfunction. Previous studies have described some neuropsychiatric side effects of this medication. So far, however, there has been little discussion about sildenafil-induced psychosis.

CASE PRESENTATION

We here present the case of a 32-year-old Iranian male, without a known psychiatric history, who developed psychotic symptoms following initiation of sildenafil. We also postulate a mechanism by which this may occur.

CONCLUSIONS

This report highlights the importance of watchful observation for the occurrence of this rare but serious side effect. Further studies are needed to clarify the precise mechanism that causes sildenafil-induced psychosis.

The network meta-analysis of "on-demand" and "daily" use of paroxetine in treating men with premature ejaculation from randomized controlled trials

This network meta-analysis aimed to assess the efficacy and safety of "on-demand" and "daily" use of paroxetine for patients with premature ejaculation (PE). We searched PubMed, Embase and Cochrane Library from inception to October 2021 to collect randomized controlled trials, and 24 articles including 2, 308 patients were finally involved. The results indicated that paroxetine (daily or on-demand) was superior to placebo at increasing intravaginal ejaculatory latency time (IELT), and 20 mg paroxetine daily was significantly better than fluoxetine and tramadol in improving IELT. Besides, 20 mg paroxetine on-demand was less effective than 20 mg paroxetine on-demand plus phosphodiesterase-5 inhibitors (PDEI5) and tramadol monotherapy in increasing IELT. Tramadol monotherapy was more effective than paroxetine monotherapy in improving sexual satisfaction score. Although patients treated with paroxetine had more coitus/week than patients treated with placebo, it was less than patients treated with PDEI5. These findings were robust to sensitivity analyses. The common adverse events related with paroxetine were fatigue, yawning and abnormal sleep (10.96%), gastrointestinal upset (10.80%). The "on-demand" and "daily" use of paroxetine can significantly improve the clinical symptoms of patients with PE and were well tolerated. Combination therapy and tramadol monotherapy can also be used as alternative treatments.

Recreational Use of Oral PDE5 Inhibitors: The Other Side of Midnight

BACKGROUND

Nowadays, Oral phosphodiesterase type 5 inhibitors (PDE5Is) are widely used for the treatment of erectile dysfunction (ED). However, these drugs have become abused among some men for recreational use to enhance their sexual performance.

OBJECTIVE

To shed a light on the recreational use of oral PDE5Is.

METHODS

A literature review was performed in the PubMed, Medline Medical Subject Heading, Science Direct, Scopus, Cochrane Library, EMBASE, CINAHL, Academic Search Complete, Google scholar, Egyptian Knowledge Bank (EKB) databases, Medline, Embase, and Chem ID using the keywords; sexual health, erectile dysfunction, recreational use/abuse, phosphodiesterase type 5 inhibitors, sildenafil, tadalafil, vardenafil, avanafil, and adverse effects.

RESULTS

Overall, 52 studies were retained for review out of 166 papers. Twenty-two studies that assessed the prevalence of the problem were investigated including 25,279 men from different countries. Most of these studies were cross-sectional studies that depend on multiple questionnaires representing the extent as well as the attitude of the recreational use of PDE5Is.

CONCLUSION

Oral PDE5Is have become used among some men for recreational use to enhance their sexual performance. To counteract the possible side effects of such abuse, the media, as well as health authorities, should be aware of the potential adverse effects of such abuse and strengthen the regulatory activity to protect the customers from such risks. Mostafa T, Alghobary MF. Recreational Use of Oral PDE5 Inhibitors: The Other Side of Midnight. Sex Med Rev 2021;XX:XXX-XXX.

Central Serous Chorioretinopathy Following Oral Use of Adulterated Honey Mixed with Tadalafil: A Case Report

Background

Central serous chorioretinopathy (CSCR) is an idiopathic condition characterized by serous retinal detachment and/or retinal pigment epithelial (RPE) detachment, the condition associated with a fluid leak through the RPE into subretinal space. This article reports on an unusual case of CSCR following taking adulterated honey mixed with tadalafil powder.

Case Presentation

A 38-year-old male, not known to have any medical illnesses, came to our ophthalmology clinic complaining of sudden onset of blurred central vision in the left eye for five days after taking an adulterated honey which was claimed to improve sexual performance. On taking a history, the patient denied taking any medications or past eye trauma or surgery. On detailed ophthalmologic examination, the best-corrected visual acuity (BCVA) was 20/20 in the right eye and 20/80 in the left eye. Dilated fundus examination of the right eye showed a flat retina, normal macular reflex, healthy optic nerve head and the left eye showed blunt foveal reflex with neurosensory retinal detachment at the macula and subretinal fluid. Optical coherence tomography (OCT) of the left eye showed marked macular thickening, leading to the impression of central serous chorioretinopathy (CSCR). Four weeks after stopping the adulterated honey, BCVA improved to 20/20 in the left eye, with complete resolution of subretinal fluids.

Conclusion

Our case adds to recently reported cases of a link between tadalafil and CSCR.

Central Retinal Artery Occlusion Associated with Sildenafil Overdose

Background

To report a patient with central retinal artery occlusion (CRAO) associated with sildenafil overdose. Case Presentation. A forty-two-year-old male presented three hours after sudden painless visual loss in the right eye. BCVA was counting finger in two meters, and relative afferent pupillary defect was positive. Fundus examination revealed retinal whiteness except in a limited area of papillomacular bundle and cherry red spot. He consumed two 100 mg film-coated sildenafil tablet (Vizarsin, Krka, d.d., Novo mesto, Slovenia) twelve hours apart, and the last one was six hours before visual loss. He was diagnosed with CRAO with cilioretinal artery sparing. Although we did not find any emboli, anterior chamber paracentesis was done. Four weeks later, BCVA improved to 20/80, with resolving of retinal edema. Cardiovascular, carotid arteries, and neurologic evaluations were negative for any predisposing factor.

Conclusion

CRAO is a vision threatening condition that might be associated with the overdose of sildenafil.

Hyperthyroidism as an Underlying Cause of Premature Ejaculation

INTRODUCTION

Hormonal imbalances have been associated with various sexual dysfunction disorders. In particular, the connection of hyperthyroidism has been discovered to correlate to premature ejaculation (PE) but has yet to been thoroughly elucidated. As one of the most frequently self-reported sexual dysfunctions, it is imperative for health care professionals to evaluate possible underlying conditions in regard to treatment options for individuals with PE.

OBJECTIVES

To review the literature regarding hyperthyroidism effects on sexual dysfunction, with a focus on hyperthyroidism and PE.

METHODS

A literature review of articles and clinical studies was performed to define the classification, pathophysiology, diagnostic considerations, and management of hyperthyroidism on PE. Search terms included "hyperthyroidism" and/or "premature ejaculation," "treatment of premature ejaculation," "defining premature ejaculation," and "management of premature ejaculation."

RESULTS

To improve the accuracy of diagnosing PE, there needs to be a set definition amongst the different guidelines, as using these guidelines can help determine possible underlying etiologies of PE. The correlation of hyperthyroidism and PE has been described in a limited number of studies. It has been reported that individuals with hyperthyroidism are much more likely to have PE than individuals with euthryoidism. Management of hyperthyroidism has been shown to alleviate the symptoms of PE.

CONCLUSION

Further understanding of hyperthyroidism as an underlying cause of PE could lead to increased efficacy of treatment and management of PE. Tannenbaum J, Youssef M, Attia AS, et al. Hyperthyroidism as an Underlying Cause of Premature Ejaculation. Sex Med Rev 2021;XX:XXX-XXX.

Novel Pyran-Linked Phthalazinone-Pyrazole Hybrids: Synthesis, Cytotoxicity Evaluation, Molecular Modeling, and Descriptor Studies

A series of novel pyran-linked phthalazinone-pyrazole hybrids were designed and synthesized by a facile one-pot three-component reaction employing substituted phthalazinone, 1H-pyrazole-5-carbaldehyde, and active methylene compounds. Optimization studies led to the identification of L-proline and ethanol as efficient catalyst and solvent, respectively. This was followed by evaluation of anticancer activity against solid tumor cell lines of lung and cervical carcinoma that displayed IC₅₀ values in the range of 9.8–41.6 µM. Molecular modeling studies were performed, and crucial interactions with the target protein were identified. The drug likeliness nature of the compounds and molecular descriptors such as molecular flexibility, complexity, and shape index were also calculated to understand the potential of the synthesized molecules to act as lead-like molecule upon further detailed biological investigations as well as 3D-QSAR studies.

Sildenafil in Combination Therapy against Cancer: A Literature Review

The concepts of drug repurposing and Sildenafil or blue pill are tightly linked over the years. Indeed, in addition to its initial clinical application as an anti-hypertensive drug in the pulmonary system, Sildenafil is also known for its beneficial effects in erectile dysfunction. Moreover, evidence has been accumulated to support its value in anti-cancer therapy, either alone or in combination with other clinically efficient chemotherapy drugs. In this review, we focused on the old and recent in vitro and in vivo studies demonstrating the cellular and molecular rationale for the application of Sildenafil in combination therapy in various types of cancer. We emphasized on the different molecular targets as well as the different signaling pathways involved in cancer cells. The pro-apoptotic effect of Sildenafil through nitric oxide (NO)/ phosphodiesterase type 5 (PDE5)-dependent manner seems to be one of the most common mechanisms. However, the activation of autophagy, as well as the modulation of the anti-tumor immunity, constitutes the other pathways triggered by Sildenafil. Overall, the studies converged to reveal the complexity of the anti-cancer potential of Sildenafil. Thus, through our review, we aimed to present an updated and simplified picture of such repurposing of Sildenafil in the field of oncology.

Premature ejaculation - current concepts in the management: A narrative review

Premature ejaculation (PE; early ejaculation or rapid ejaculation) is a common sexual problem affecting about 20-30% of men in the sexually active age group. PE can be of four types: Primary, secondary, natural variable, and subjective PE. Various non-pharmacological and pharmacological treatment options are available to treat PE including Dapoxetine, which is specifically developed for the treatment of PE. In this review, we discuss the pathophysiology and management aspects of PE.

Sildenafil beyond erectile dysfunction and pulmonary arterial hypertension: Thinking about new indications

Sildenafil, approved two decades ago, is the inhibitor of phosphodiesterase 5 (PDE5). First of all, it was designated for angina pectoris, but soon it showed a wonderful efficacy in erectile dysfunction (ED) and then pulmonary arterial hypertension (PAH). Due to the distribution of phosphodiesterase (PDE) in almost all organs, maybe it effects other diseases. Hence, a great number of investigations began to understand the role of PDEi in different organs. Preliminary research on sildenafil in cell culture and animal models has yielded promising results. Soon, a greater number of animal researches and clinical trials joined them. The results disclosed sildenafil can have beneficial effects in each organ such as heart, liver, kidney, brain, and intestines. Furthermore, it has significantly improved the prognosis of organ ischemia in various animal models. Clinical trials in several diseases, such as recurrent spontaneous miscarriage, fatty liver disease, bronchopulmonary dysplasia (BPD), heart failure, and premature ejaculation (PE) brought promising results. Although some clinical trials are available on the effects of sildenafil on various diseases, further studies on humans are needed to consolidate the ultimate effects of sildenafil. The aim of this review was to describe the effects of sildenafil on each organ and explain its mechanisms of action. Further, other PDE inhibitors such as tadalafil and vardenafil have been briefly discussed in parts of this review.

Selective dorsal neurotomy in the treatment of premature ejaculation: A protocol for systematic review and meta-analysis

INTRODUCTION

Premature ejaculation (PE) affects 8% to 30% of adult men worldwide. Recently, the incidence of PE is on the rise. A series of prior studies suggested that the incidence of PE is related to various biological factors as low testosterone, low serum vitamin D, diabetes, lower urinary tract symptoms, and other psychological factors. At present, the major treatments include selective serotonin reuptake inhibitors antidepressants (dapoxetine, paroxetine), topical anesthetics, phosphodiesterase-5 inhibitor, circumcision, and selective dorsal neurotomy (SDN). The previous study found that SDN is effective for PE.

METHODS AND ANALYSIS

The electronic databases of MEDLINE, PubMed, Web of Science, EMBASE, Cochrane Library, Clinicaltrials. org, China National Knowledge Infrastructure Database (CNKI), Wan fang Database, China Biology Medicine Database (CBM), VIP Science Technology Periodical Database, Chinese Clinical Trial Registry will be retrieved. All the randomized controlled trials of selective dorsal penile neurotomy for patients with PE will be included. The outcome includes intravaginal ejaculation latency time and Chinese Index of Sexual Function for Premature Ejaculation-5. We will conduct this study strictly according to the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

The present study is a protocol for systematic review and meta-analysis without results, and data analysis will be carried out after the protocol. We will share our findings on June 30th of 2021.

CONCLUSION

SDN can effectively prolong IELT, but its efficacy has not been assessed scientifically and systematically. To address this limitation, this study will inspect the efficacy and safety of the SDN treatment in patients with PE.

ETHICS AND DISSEMINATION

Formal ethical approval is not required in this protocol. We will collect and analyze data based on published studies, and since there are no patients involved in this study, individual privacy will not be under concerns. The results of this review will be disseminated to peer-reviewed journals or submit to related conferences.

PROTOCOL REGISTRATION NUMBER

INPLASY202070084.

Sildenafil-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms: Case report with review

Sildenafil is one of the commonest over the counter drugs which is orally taken by the people for sexual enhancement. It is an inhibitor of phosphodiesterase type 5 (PDE5) and results in engorgement of carpora cavernosa and help in erectile dysfunction. There are fewer adverse cutaneous drug reactions reported by sildenafil perhaps due to use of the drug without medical prescription. Here we are reporting a case of sildenafil induced hypersensitivity syndrome that is possibly the first one and reviewing the medical literature on type of adverse cutaneous drug eruption due to sildenafil and other PDE5 inhibitors.