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Alamer AA, Alshehri AA, Aodah AH, Almughem FA, Alghmadi HA, Alali AS, Halwani AA, Muqtader Ahmed M, Tawfik EA. Development and evaluation of sildenafil/glycyrrhizin-loaded nanofibers as a potential novel buccal delivery system for erectile dysfunction. Saudi Pharm J 2024; 32:102038. [PMID: 38525266 PMCID: PMC10960110 DOI: 10.1016/j.jsps.2024.102038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 03/14/2024] [Indexed: 03/26/2024] Open
Abstract
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.
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Affiliation(s)
- Ali A. Alamer
- Advanced Diagnostics and Therapeutics Institute, Health Sector, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Abdullah A. Alshehri
- Advanced Diagnostics and Therapeutics Institute, Health Sector, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Alhassan H. Aodah
- Advanced Diagnostics and Therapeutics Institute, Health Sector, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Fahad A. Almughem
- Advanced Diagnostics and Therapeutics Institute, Health Sector, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Hamzah A. Alghmadi
- Advanced Diagnostics and Therapeutics Institute, Health Sector, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
| | - Amer S. Alali
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, AlKharj 11942, Saudi Arabia
| | - Abdulrahman A. Halwani
- Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Mohammed Muqtader Ahmed
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, AlKharj 11942, Saudi Arabia
| | - Essam A. Tawfik
- Advanced Diagnostics and Therapeutics Institute, Health Sector, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442, Saudi Arabia
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Zhou X, Zhang J, Gu L, Zhou H, Zhang J. Case report: Bilateral central serous chorioretinopathy-like abnormalities in a man with pulmonary arterial hypertension. Front Med (Lausanne) 2022; 9:983548. [PMID: 35979218 PMCID: PMC9376321 DOI: 10.3389/fmed.2022.983548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 07/13/2022] [Indexed: 12/02/2022] Open
Abstract
Background Pulmonary arterial hypertension (PAH) leads to progressive increases in pulmonary vascular resistance, right heart failure, and death if left untreated. Ocular complications secondary to PAH were less reported. In this study, we reported a case of bilateral visual loss and metamorphopsia in a patient with PAH, who developed central serous chorioretinopathy (CSCR)-like abnormalities and optic disc atrophy. Case summary A 45-year-old man presented with decreasing central vision and metamorphopsia in both eyes. He had a history of PAH and 6-year history of low-dose oral sildenafil treatment. Slit-lamp examination revealed prominent dilated and tortuous episcleral and conjunctival vessels. Ultrawide-field color picture showed retinal pigment epithelial mottling and atrophy in ring-like configurations. Ultrawide-field autofluorescence showed multiple irregular hyper-autofluorescence with a constellation-like pattern surrounding the optic nerve head and macular region. Optical coherence tomography angiography (OCTA) b-scan demonstrated CSCR-like changes. Swept-source optical coherence tomography (SS-OCT) analysis showed optic nerve atrophy with enlarged cup/disc ratio in right eye, which was confirmed with perimetry. Fluorescein angiography (FA) showed marked leakage of macula and optic nerve head with time, cystoid macular edema, early blocking with late staining of the flecks as shown in the backgrounds of infrared and autofluorescence, and mild leakage in peripheral retina. Indocyanine green angiography (ICGA) showed dilation, tortuosity and congestion of all vortex veins without obvious leakage. Conclusion Undertreated PAH may cause the congestion of the choroid and induce CSCR-like abnormalities.
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Affiliation(s)
- Xinrong Zhou
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People’s Hospital), Shanghai Jiao Tong University, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
- Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Jingxiang Zhang
- Nursing Department, People’s Hospital of Huangdao District, Qingdao, China
| | - Limin Gu
- Department of Ophthalmology, Shanghai Aier Eye Hospital, Shanghai, China
| | - Hao Zhou
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People’s Hospital), Shanghai Jiao Tong University, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
- Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Jingfa Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People’s Hospital), Shanghai Jiao Tong University, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai, China
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
- Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
- *Correspondence: Jingfa Zhang,
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Central Retinal Artery Occlusion Associated with Sildenafil Overdose. Case Rep Ophthalmol Med 2021; 2021:2006271. [PMID: 34527380 PMCID: PMC8437635 DOI: 10.1155/2021/2006271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 08/17/2021] [Indexed: 11/17/2022] Open
Abstract
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.
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Jain AK, Sharma P. Ethionamide induced blue vision (cyanopsia): Case report. Indian J Tuberc 2020; 67:333-335. [PMID: 32825860 DOI: 10.1016/j.ijtb.2019.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 04/22/2019] [Indexed: 06/11/2023]
Abstract
Ethionamide is part of a group of drugs used in the treatment of drug resistant TB. With the advent of increasing drug resistance in pulmonary TB cases, use of Ethionamide, a second line anti tubercular drug is increasing. Vision changes are rare with ethionamide. Cyanopsia i.e., bluish tinted vision of surroundings with ethionamide is not known in literature. Here, we report a case of DRTB patient who developed cyanopsia soon after introducing ethionamide. Although reversible, ethionamide may sometimes need withdrawal because of significant distress caused to patient.
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Affiliation(s)
- A K Jain
- National Institute of TB and Respiratory Diseases (NITRD), India
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Yilmaz H, Gultekin MH, Yalcin A. Erectile dysfunction and retinal microvascular network: an optical coherence tomography angiography study. Int J Impot Res 2020; 33:318-324. [PMID: 32346132 DOI: 10.1038/s41443-020-0289-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 04/03/2020] [Accepted: 04/09/2020] [Indexed: 11/09/2022]
Abstract
The aims of this study were to examine the microvascular network of the retina using the optical coherence tomography angiography (OCT-A) device in patients with erectile dysfunction (ED) and to determine whether the OCT-A values could assist in the differential diagnosis of ED. The study design was prospective, observational, and cross-sectional. The vessel densities (VD) of the superficial capillary plexus (SCP), deep capillary plexus (DCP), and retinal peripapillary capillary plexus (RPCP) were assessed using OCT-A in patients with ED and healthy subjects. All the participants were evaluated and scanned for systemic and hormonal disorders and those with ED also underwent penile Doppler ultrasonography (PDU). After recording the data, the participants were divided into three groups: organic ED, psychogenic ED, and healthy control. The relationships between the OCT-A parameters and other clinical findings were analyzed. The right eyes of 80 patients with ED and 40 healthy volunteers were evaluated in this study. Of the ED patients, 46 were included in the organic ED group according to the results of PDU. The VDs of DCP, SCP, and the temporal sector of RPCP were significantly lower in the organic ED group than the psychogenic ED and healthy control groups. The VDs of SCP and DCP were correlated with the peak systolic velocity of both left and right penile cavernous arteries. The VDs of DCP were also correlated with the left and right resistive indexes. In conclusion, the OCT-A data of SCP and especially DCP could be helpful in evaluating ED, and provide reliable information about the origin of the disease along with the other laboratory testing and penile vascular evaluation.
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Affiliation(s)
- Hayati Yilmaz
- Department of Ophthalmology, Mengucek Gazi Training and Research Hospital, Binali Yildirim University, Erzincan, Turkey.
| | - Mehmet Hamza Gultekin
- Department of Urology, Mengucek Gazi Training and Research Hospital, Binali Yildirim University, Erzincan, Turkey
| | - Ahmet Yalcin
- Department of Radiology, Mengucek Gazi Training and Research Hospital, Binali Yildirim University, Erzincan, Turkey
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Ammar HO, Tadros MI, Salama NM, Ghoneim AM. Therapeutic Strategies for Erectile Dysfunction With Emphasis on Recent Approaches in Nanomedicine. IEEE Trans Nanobioscience 2019; 19:11-24. [PMID: 31567099 DOI: 10.1109/tnb.2019.2941550] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This review addressed erectile dysfunction, regarding pathophysiology and therapeutic strategies. The line of treatment includes phosphodiesterase type-5 inhibitors and other types of therapy like topical and stem-cell transplant. Scientific literature was assessed to investigate the impact of nanotechnology on erectile dysfunction therapy. Various nanotechnology approaches were applied, like vesicular systems, lipid-based carriers, nanocrystals, dendrimers, liquid crystalline systems and nanoemulsions. Smart nano-systems can alter the landscape of the modern pharmaceutical industry by re- investigation of pharmaceutically suboptimal but biologically active entities for treatment of erectile dysfunction which were previously considered undeveloped.
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Gul M, Serefoglu EC. An update on the drug safety of treating erectile dysfunction. Expert Opin Drug Saf 2019; 18:965-975. [DOI: 10.1080/14740338.2019.1659244] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Murat Gul
- Department of Urology, Aksaray University School of Medicine, Aksaray, Turkey
- Laboratory of Reproductive Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ege Can Serefoglu
- Department of Urology, Bahceci Health Group, Istanbul, Turkey
- Department of Embriology and Histology, Medipol University, Istanbul, Turkey
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8
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Krishnappa P, Fernandez-Pascual E, Carballido J, Martinez-Salamanca JI. Sildenafil/Viagra in the treatment of premature ejaculation. Int J Impot Res 2019; 31:65-70. [DOI: 10.1038/s41443-018-0099-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 10/27/2018] [Accepted: 11/07/2018] [Indexed: 11/09/2022]
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Pattis JG, Kamal S, Li B, May ER. Catalytic Domains of Phosphodiesterase 5, 6, and 5/6 Chimera Display Differential Dynamics and Ligand Dissociation Energy Barriers. J Phys Chem B 2019; 123:825-835. [PMID: 30616346 PMCID: PMC6502234 DOI: 10.1021/acs.jpcb.8b11370] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The enzyme phosphodiesterase 6 (PDE6) is a critical component of the visual signaling pathway and functions to convert cGMP to GMP. The ability of PDE6 to affect cellular cGMP levels leads to deactivation of cGMP-gated ion channels in both rod and cone cells. PDE6 has been difficult to structurally characterize experimentally, though the structures of the closely related PDE5 and a PDE5/6 chimera have been determined by X-ray crystallography. In this work, we employ a computational approach to study the dynamics of the catalytic domains of PDE6, PDE5, and the PDE5/6 chimera. Through equilibrium molecular dynamics (MD) simulations, we identify a region of PDE6 (α12) to be correlated to distal regions of the enzyme (H- and M-loops), which surround the catalytic center. These correlations are not observed for PDE5, and we speculate that these unique motions in PDE6 may relate to the high catalytic efficiency of PDE6 and the requirement for an endogenous inhibitory subunit (Pγ). We further investigate the ligand binding pathways and energetics by enhanced sampling simulations (metadynamics) using the inhibitor sildenafil and GMP. The energetics and pathways of ligand binding are consistent with the high efficiency of PDE6 and further implicate the α12 region as an important regulatory element for PDE6 functional dynamics.
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Affiliation(s)
| | | | - Boyang Li
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269
| | - Eric R. May
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269
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Affiliation(s)
- Robin E Ferner
- West Midlands Centre for Adverse Drug Reactions, City Hospital, Birmingham B18 7QH, UK
| | - Patricia McGettigan
- William Harvey Research Institute, Queen Mary University of London, London EC1M 6BQ, UK
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11
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Unilateral transient cyanopsia as an early symptom of compressive optic neuropathy. Neurol Sci 2018; 39:2221-2222. [PMID: 30143919 DOI: 10.1007/s10072-018-3535-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 08/10/2018] [Indexed: 10/28/2022]
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12
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Campbell UB, Walker AM, Gaffney M, Petronis KR, Creanga D, Quinn S, Klein BE, Laties AM, Lewis M, Sharlip ID, Kolitsopoulos F, Klee BJ, Mo J, Reynolds RF. Acute Nonarteritic Anterior Ischemic Optic Neuropathy and Exposure to Phosphodiesterase Type 5 Inhibitors. J Sex Med 2015; 12:139-51. [DOI: 10.1111/jsm.12726] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Nivison-Smith L, Zhu Y, Whatham A, Bui BV, Fletcher EL, Acosta ML, Kalloniatis M. Sildenafil alters retinal function in mouse carriers of Retinitis Pigmentosa. Exp Eye Res 2014; 128:43-56. [DOI: 10.1016/j.exer.2014.08.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 08/22/2014] [Accepted: 08/28/2014] [Indexed: 11/17/2022]
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Katz EG, Tan RB, Rittenberg D, Hellstrom WJ. Avanafil for erectile dysfunction in elderly and younger adults: differential pharmacology and clinical utility. Ther Clin Risk Manag 2014; 10:701-11. [PMID: 25210457 PMCID: PMC4155803 DOI: 10.2147/tcrm.s57610] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
The treatment modalities of erectile dysfunction range from oral pharmacotherapy to intracavernosal injections, intraurethral pellets, vacuum erectile devices, and the surgical option of penile prosthesis insertion. Oral phosphodiesterase 5 inhibitors still remain the preferred treatment for patients since they are the least invasive, not to mention that they can be prescribed by non-urologists. Due to these factors, there has been development of newer drugs with fewer side effects. This is a review of the second generation phosphodiesterase 5 inhibitor, avanafil, looking into its pharmacology as well as its clinical utility. Avanafil’s faster onset and shorter duration of action has made it preferred as compared to other PDE5 inhibitors for patients with multiple comorbidities.
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Affiliation(s)
- Eric G Katz
- Tulane University School of Medicine, New Orleans, LA, USA
| | - Ronny Bw Tan
- Department of Urology, Tan Tock Seng Hospital, Singapore
| | | | - Wayne J Hellstrom
- Section of Andrology, Department of Urology, Tulane University School of Medicine, New Orleans, LA, USA
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Abstract
Iatrogenic disease is one of the most frequent causes of hospital admissions and constitutes a growing public health problem. The most common type of iatrogenic neurologic disease is pharmacologic, and the central and peripheral nervous systems are particularly vulnerable. Despite this, iatrogenic disease is generally overlooked as a differential diagnosis among neurologic patients. The clinical picture of pharmacologically mediated iatrogenic neurologic disease can range from mild to fatal. Common and uncommon forms of drug toxicity are comprehensively addressed in this chapter. While the majority of neurologic adverse effects are listed and referenced in the tables, the most relevant issues are further discussed in the text.
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Affiliation(s)
- Luciano A Sposato
- Department of Clinical Neurological Sciences, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada
| | - Osvaldo Fustinoni
- INEBA Institute of Neurosciences, Buenos Aires, Argentina; Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina.
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Chaumais MC, Perrin S, Sitbon O, Simonneau G, Humbert M, Montani D. Pharmacokinetic evaluation of sildenafil as a pulmonary hypertension treatment. Expert Opin Drug Metab Toxicol 2013; 9:1193-205. [DOI: 10.1517/17425255.2013.804063] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Marie-Camille Chaumais
- Université Paris-Sud, Faculté de Pharmacie,
Chatenay-Malabry, France
- AP-HP, Service de Pharmacie, DHU Thorax Innovation, Hôpital Antoine Béclère,
Clamart, France
- INSERM UMR 999, LabEx LERMIT, DHU Thorax Innovation, Centre Chirurgical Marie Lannelongue,
Le Plessis Robinson, France
| | - Swanny Perrin
- INSERM UMR 999, LabEx LERMIT, DHU Thorax Innovation, Centre Chirurgical Marie Lannelongue,
Le Plessis Robinson, France
- Université Paris-Sud, Faculté de Médecine,
Kremlin-Bicêtre, France
- AP-HP, Centre de Référence de l’Hypertension Pulmonaire Sévère, Service de Pneumologie et Réanimation Respiratoire, DHU Thorax Innovation, Hôpital de Bicêtre,
78, rue du Général Leclerc, 94270 Le Kremlin-Bicêtre, France .
| | - Olivier Sitbon
- INSERM UMR 999, LabEx LERMIT, DHU Thorax Innovation, Centre Chirurgical Marie Lannelongue,
Le Plessis Robinson, France
- Université Paris-Sud, Faculté de Médecine,
Kremlin-Bicêtre, France
- AP-HP, Centre de Référence de l’Hypertension Pulmonaire Sévère, Service de Pneumologie et Réanimation Respiratoire, DHU Thorax Innovation, Hôpital de Bicêtre,
78, rue du Général Leclerc, 94270 Le Kremlin-Bicêtre, France .
| | - Gérald Simonneau
- INSERM UMR 999, LabEx LERMIT, DHU Thorax Innovation, Centre Chirurgical Marie Lannelongue,
Le Plessis Robinson, France
- Université Paris-Sud, Faculté de Médecine,
Kremlin-Bicêtre, France
- AP-HP, Centre de Référence de l’Hypertension Pulmonaire Sévère, Service de Pneumologie et Réanimation Respiratoire, DHU Thorax Innovation, Hôpital de Bicêtre,
78, rue du Général Leclerc, 94270 Le Kremlin-Bicêtre, France .
| | - Marc Humbert
- INSERM UMR 999, LabEx LERMIT, DHU Thorax Innovation, Centre Chirurgical Marie Lannelongue,
Le Plessis Robinson, France
- Université Paris-Sud, Faculté de Médecine,
Kremlin-Bicêtre, France
- AP-HP, Centre de Référence de l’Hypertension Pulmonaire Sévère, Service de Pneumologie et Réanimation Respiratoire, DHU Thorax Innovation, Hôpital de Bicêtre,
78, rue du Général Leclerc, 94270 Le Kremlin-Bicêtre, France .
| | - David Montani
- INSERM UMR 999, LabEx LERMIT, DHU Thorax Innovation, Centre Chirurgical Marie Lannelongue,
Le Plessis Robinson, France
- Université Paris-Sud, Faculté de Médecine,
Kremlin-Bicêtre, France
- AP-HP, Centre de Référence de l’Hypertension Pulmonaire Sévère, Service de Pneumologie et Réanimation Respiratoire, DHU Thorax Innovation, Hôpital de Bicêtre,
78, rue du Général Leclerc, 94270 Le Kremlin-Bicêtre, France .
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Damar E, Toklu Y, Tuncel A, Balci M, Aslan Y, Simsek S, Atan A. Does therapeutic dose of sildenafil citrate treatment lead to central serous chorioretinopathy in patients with erectile dysfunction? Am J Mens Health 2013; 7:439-43. [PMID: 23479433 DOI: 10.1177/1557988313480808] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The possible effects of sildenafil citrate administration at therapeutic dosage on visual acuity, color vision, intraocular pressure, macular thickness, macular volume, and central serous chorioretinopathy in patients with erectile dysfunction were evaluated. The study consisted of 43 male patients diagnosed as having erectile dysfunction according to the first five question version of International Index of Erectile Function (IIEF-5). All patients were given sildenafil citrate 50 mg po 2 to 3 times/week for a month. The patients were evaluated at the first week and at the end of the treatment. The macular thickness and volume assessments with optic coherence tomography did not differ significantly in foveal, parafoveal areas, parafoveal superior hemisphere, parafoveal inferior hemisphere, parafoveal temporal, superior, nasal, and inferior quadrants. Central serous chorioretinopathy was not found in any of the patients.
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Affiliation(s)
- Elif Damar
- Ministry of Health, Ankara Ataturk Research and Training Hospital, Department of Ophthalmology, Ankara, Turkey
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Abstract
OBJECTIVE Sildenafil is occasionally used as rescue treatment for preterm infants with severe bronchopulmonary dysplasia and pulmonary arterial hypertension. In adults, sildenafil treatment has been associated with several ophthalmological adverse effects, including nonarteritic ischaemic optic neuropathy. We reviewed the effect of sildenafil on retinopathy of prematurity (ROP) in very preterm infants. STUDY DESIGN Retrospective case-control study. Infants born <30 weeks gestation who had received sildenafil during their hospitalisation were included. A control group matched for gestation, birth weight, gender, and place of birth was identified from the departmental database. For every sildenafil case, three matched controls were studied. Baseline data, sildenafil therapy data, results of eye examinations and respiratory data were analysed. RESULT 17 infants received sildenafil between 2004 and 2010. The median duration of sildenafil treatment was 52 days. Baseline characteristics were similar between groups. The odds ratio for an increase in ROP stage in the group treated with sildenafil was 1.35 (95% confidence interval 0.39-4.62, P-value 0.63). One infant in each group required laser treatment. CONCLUSION Sildenafil treatment did not affect ROP progression or increase the need for laser treatment in this cohort.
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Cahill KB, Quade JH, Carleton KL, Cote RH. Identification of amino acid residues responsible for the selectivity of tadalafil binding to two closely related phosphodiesterases, PDE5 and PDE6. J Biol Chem 2012; 287:41406-16. [PMID: 23033484 DOI: 10.1074/jbc.m112.389189] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The 11 families of the Class I cyclic nucleotide phosphodiesterases (PDEs) are critical for regulation of cyclic nucleotide signaling. PDE5 (important in regulating vascular smooth muscle contraction) and PDE6 (responsible for regulating visual transduction in vertebrate photoreceptors) are structurally similar but have several functional differences whose structural basis is poorly understood. Using evolutionary trace analysis and structural homology modeling in conjunction with site-directed mutagenesis, we have tested the hypothesis that class-specific differences between PDE5 and PDE6 account for the biochemical and pharmacological differences in the two enzyme families. Replacing human PDE5 residues in the M-loop region of the binding site for the PDE5-selective inhibitor tadalafil (Cialis®) with the corresponding class-specific cone PDE6 residues (P773E, I778V, E780L, F787W, E796V, D803P, L804M, N806D, I813L, S815K) reduces tadalafil binding affinity to levels characteristic of PDE6. These mutations fail to alter vardenafil (Levitra®) affinity for the active site. Class-specific differences in PDE5 versus cone PDE6 that contribute to the accelerated catalytic efficiency of PDE6 were identified but required heterologous expression of full-length PDE5 constructs. Introduction of PDE6 residues into the background of the PDE5 protein sequence often led to loss of catalytic activity and reduced protein solubility, supporting the idea that multiple structural elements of PDE6 are highly susceptible to misfolding during heterologous expression. This work validates the use of PDE5 as a template to identify functional differences between PDE5 and PDE6 that will accelerate efforts to develop the next generation of PDE5-selective inhibitors with fewer adverse side effects resulting from PDE6 inhibition.
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Affiliation(s)
- Karyn B Cahill
- Department of Molecular, Cellular and Biomedical Sciences University of New Hampshire, Durham, New Hampshire 03824, USA
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Gokulgandhi MR, Vadlapudi AD, Mitra AK. Ocular toxicity from systemically administered xenobiotics. Expert Opin Drug Metab Toxicol 2012; 8:1277-91. [PMID: 22803583 DOI: 10.1517/17425255.2012.708337] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The eye is considered as the most privileged organ because of the blood-ocular barrier that acts as a barrier to systemically administered xenobiotics. However, there has been a significant increase in the number of reports on systemic drug-induced ocular complications. If such complications are left untreated, then it may cause permanent damage to vision. Hence, knowledge of most recent updates on ever-increasing reports of such toxicities has become imperative to develop better therapy while minimizing toxicities. AREAS COVERED The article is mainly divided into anterior and posterior segment manifestations caused by systemically administered drugs. The anterior segment is further elaborated on corneal complications where as the posterior segment is focused on optic nerve, retinal and vitreous complications. Furthermore, this article includes recent updates on acute and chronic ocular predicaments, in addition to discussing various associated symptoms caused by drugs. EXPERT OPINION Direct correlation of ocular toxicities due to systemic drug therapy is evident from current literature. Therefore, it is necessary to have detailed documentation of these complications to improve understanding and predict toxicities. We made an attempt to ensure that the reader is aware of the characteristic ocular complications, the potential for irreversible drug toxicity and indications for cessation.
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Affiliation(s)
- Mitan R Gokulgandhi
- University of Missouri-Kansas City, School of Pharmacy, Division of Pharmaceutical Sciences, HSB 5258, 2464 Charlotte St, Kansas City, MO 64108, USA
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Rezvanfar MA, Rahimi HR, Abdollahi M. ADMET considerations for phosphodiesterase-5 inhibitors. Expert Opin Drug Metab Toxicol 2012; 8:1231-45. [PMID: 22769968 DOI: 10.1517/17425255.2012.698610] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
INTRODUCTION ADMET (absorption, distribution, metabolism, excretion, and toxicity) profiling is an important aspect of all drug developments. The pharmaceutical industry must always consider ADMET properties in order to optimize drug candidates and to introduce new formulations against existing marketed drugs. Consequently, candidate drug development may be halted early in the discovery phase or during the more costly drug development process because of their poor ADMET properties. AREAS COVERED The main focus of this article is ADMET profiling, pharmacokinetic (PK) drug interactions, mechanisms and possible adverse drug reactions (ADRs) for approved phosphodiesterase-5 inhibitors (PDE5Is). The authors also look at the efficacy and non-erectogenic benefits of current PDE5Is, which are widely used by patients with erectile dysfunction (ED). The authors also discuss other unapproved PDE5Is such as aildenafil and udenafil, which are currently in use in clinical trials. EXPERT OPINION The authors believe that the enhancing effect of PDE5Is on the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway means that PDE5Is could be used to treat various conditions. An important issue in their development is 'cross-talk' between PDE5 and other PDEs and thus their specificity for other PDEs. But while it might be difficult to achieve the ideal ADMET profile, it should not necessarily prevent further development of a lead PDE5I. The risk assessment of PDE5Is, with respect to their ADMET properties, is therefore very important for predicting drug-drug interactions, possible side effects, ADRs and its future clinical applications.
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Affiliation(s)
- Mohammad Amin Rezvanfar
- Tehran University of Medical Sciences, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Department of Toxicology and Pharmacology, Tehran, Iran
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Porst H, Hell-Momeni K, Büttner H. Chronic PDE-5 inhibition in patients with erectile dysfunction – a treatment approach using tadalafil once-daily. Expert Opin Pharmacother 2012; 13:1481-94. [DOI: 10.1517/14656566.2012.693162] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Sung HH, Lee SW. Chronic low dosing of phosphodiesterase type 5 inhibitor for erectile dysfunction. Korean J Urol 2012; 53:377-85. [PMID: 22741044 PMCID: PMC3382685 DOI: 10.4111/kju.2012.53.6.377] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 04/19/2012] [Indexed: 01/02/2023] Open
Abstract
Oral phosphodiesterase type 5 (PDE5) inhibitors have provided non-invasive, effective, and well-tolerated treatments for patients with erectile dysfunction (ED). However, many patients with ED are unresponsive to 'on-demand' PDE5 inhibitors. In addition, the lack of spontaneity and naturalness of the on-demand regimen could be a reason for decreased compliance with PDE5 inhibitors. Recently, tadalafil and udenafil were approved for low-dose daily administration for the treatment of ED. Since the introduction of the concept of daily administration of PDE5 inhibitors, several reports have supported the potential benefits of this therapy for disease modification, improvement of the treatment response in difficult-to-treat populations, spontaneity, and safety, although further research is needed to better address these hypotheses. In this article, we reviewed the daily administration of PDE5 inhibitors in terms of pharmacokinetics, safety, efficacy, and distinct features.
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Affiliation(s)
- Hyun Hwan Sung
- Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Wirostko BM, Tressler C, Hwang LJ, Burgess G, Laties AM. Ocular safety of sildenafil citrate when administered chronically for pulmonary arterial hypertension: results from phase III, randomised, double masked, placebo controlled trial and open label extension. BMJ 2012; 344:e554. [PMID: 22354598 PMCID: PMC3283528 DOI: 10.1136/bmj.e554] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To assess the ocular effects and safety profile of chronic sildenafil oral dosing in patients with pulmonary arterial hypertension. DESIGN 12 week, double masked, randomised, placebo controlled, phase III trial with open label extension. SETTING 53 institutions worldwide. PARTICIPANTS 277 adults with idiopathic pulmonary arterial hypertension or pulmonary arterial hypertension associated with connective tissue disease or after congenital heart disease repair (mean pulmonary artery pressure ≥25 mm Hg; pulmonary capillary wedge pressure ≤15 mm Hg at rest). INTERVENTIONS During the double masked study, oral sildenafil 20 mg, 40 mg, or 80 mg or placebo (1:1:1:1) three times daily for 12 weeks was added to baseline drug treatment. In the extension study, the placebo, 20 mg and 40 mg groups received 40 mg three times daily titrated to 80 mg three times daily at week 6. After unmasking, the dose was titrated according to clinical need. MAIN OUTCOME MEASURE Ocular safety (ocular examinations, visual function tests, participants' reports of adverse events, and visual disturbance questionnaire completed by investigators) by treatment group at 12 weeks, 24 weeks, 18 months, and yearly. RESULTS Findings of the objective assessments-that is, intraocular pressure and visual function tests (visual acuity, colour vision, and visual field)-were similar across groups (20 mg, n=69; 40 mg, n=67; 80 mg, n=71; placebo, n=70). No clinically significant changes occurred between baseline and 12 weeks, except for an efficacy signal in contrast sensitivity for the sildenafil 40 mg three times daily group. In right eyes, changes in intraocular pressure from baseline to week 12 ranged from a mean of -0.5 (95% confidence interval -1.3 to 0.2) mm Hg with placebo, -0.2 (-0.9 to 0.5) mm Hg with sildenafil 40 mg, and -0.1 (-0.7 to 0.5) mm Hg with 80 mg to 0.3 (-0.4 to 0.9) mm Hg with sildenafil 20 mg (the approved dose for pulmonary arterial hypertension). Mean changes from baseline to week 12 in contrast sensitivity in right eyes were -0.02 (SD 0.12) in the sildenafil 20 mg three times daily group compared with -0.05 (0.18) in the placebo group (P=0.044). Percentages of participants with deterioration in visual acuity (Snellen) from baseline to week 12 ranged from 10% (n=7) in the placebo group to 3% (n=2) in the sildenafil 20 mg three times daily group; the same percentages had visual field changes from normal to abnormal during the period in these two groups. The investigators did not deem any findings on colour vision assessment to be clinically significant. Findings of the objective assessments in the 40 mg and 80 mg three times daily sildenafil treatment groups and in left eyes were not substantially different, nor were any measures different throughout the open label extension compared with week 12. However, objective data were limited after month 18, as most participants had missing data or visual parameters were no longer collected by investigators. Incidence of ocular adverse events reported on the case report forms and assessed by the investigator was low with all doses, but a modest, dose related incidence of chromatopsia, cyanopsia, photophobia, and visual disturbance was reported with 80 mg three times daily consistent with the indicated dosing for erectile dysfunction. Retinal haemorrhages, captured on funduscopy, occurred in 2% (4/207) of sildenafil treated participants and none in the placebo group during the double masked study and in 4% (10/259) during the open label extension. CONCLUSIONS Sildenafil dosing up to 80 mg three times daily is safe and well tolerated from an ocular perspective in patients with pulmonary arterial hypertension. Daily chronic dosing in this patient population was not associated with visual change and had no detrimental effect on best corrected visual acuity, contrast sensitivity, colour vision, or visual field, or on slit lamp examinations, funduscopy, or intraocular pressure during the duration of this study. TRIAL REGISTRATION Clinical trials NCT00644605 and NCT00159887.
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Focus on Phosphodiesterase Inhibitors for the Treatment of Erectile Dysfunction in Older Men. Clin Ther 2011; 33:1590-608. [DOI: 10.1016/j.clinthera.2011.09.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 09/24/2011] [Accepted: 09/26/2011] [Indexed: 11/19/2022]
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Limin M, Johnsen N, Hellstrom WJG. Avanafil, a new rapid-onset phosphodiesterase 5 inhibitor for the treatment of erectile dysfunction. Expert Opin Investig Drugs 2010; 19:1427-37. [DOI: 10.1517/13543784.2010.518955] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Kehat R, Bonsall DJ, North R, Connors B. Ocular findings of oral sildenafil use in term and near-term neonates. J AAPOS 2010; 14:159-62. [PMID: 20199882 DOI: 10.1016/j.jaapos.2009.12.161] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 12/02/2009] [Accepted: 12/11/2009] [Indexed: 10/19/2022]
Abstract
BACKGROUND Sildenafil is a phosphodiesterase type 5 inhibitor used as a therapeutic adjunct in critically ill neonates with persistent pulmonary hypertension. Sildenafil is associated with several ocular complications in adults and is suspected to exacerbate retinopathy of prematurity (ROP). The risk of ocular complication in sildenafil-treated newborns, not otherwise at risk for the development of ROP, is unknown. METHODS Twenty-two neonates with birth gestational age greater than 34 weeks and birth weight over 2,100 g who received oral sildenafil for more than 2 weeks were assessed by a pediatric ophthalmologist for potential ocular complications. RESULTS Four patients had ocular findings: 2 had bacterial conjunctivitis; 1 had optic nerve hypoplasia, choroidal coloboma, and nystagmus; 1 had previously suffered from a hypotensive episode and had a documented cortical injury accompanied by bilateral optic disk atrophy and nystagmus. All cases seemed unrelated to sildenafil use and improved despite continued use of the drug. CONCLUSIONS Our results do not support the need for a routine ophthalmologic examination in term and near-term neonates receiving sildenafil.
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Affiliation(s)
- Rinat Kehat
- Israel Institute of Technology, Haifa, Israel
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Giuliano F, Jackson G, Montorsi F, Martin-Morales A, Raillard P. Safety of sildenafil citrate: review of 67 double-blind placebo-controlled trials and the postmarketing safety database. Int J Clin Pract 2010; 64:240-55. [PMID: 19900167 PMCID: PMC2810448 DOI: 10.1111/j.1742-1241.2009.02254.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
AIM To review special safety topics associated with sildenafil and to document the tolerability of 50- and 100-mg doses, overall and by age, in men with erectile dysfunction (ED). METHODS Data were collated from 67 double-blind placebo-controlled (DBPC) trials (> 14,000 men) conducted by the manufacturer and from the manufacturer's postmarketing safety database (39,277 patients). The DBPC data were stratified by dose, starting dose and age (> or = 65 and > or = 75 years). Special safety topics included cardiovascular risk, priapism, non-arteritic anterior ischaemic optic neuropathy (NAION), impaired renal and hepatic function, drug interactions (i.e. nitrates, cytochrome P3A4 inhibitors, other ED therapies and alpha-blockers) and incorrect use. RESULTS Sildenafil was well tolerated at a dose of 50 or 100 mg in men with ED, overall, in those aged > or = 65 years, and in those aged > or = 75 years. Analyses of the databases did not reveal any causal link between sildenafil and cardiovascular events, or any new safety risks relating to cardiovascular events, priapism, NAION, hearing loss or drug interactions. In the small number of men with moderate impairment of renal function or hepatic function who were treated with sildenafil in DBPC trials, the safety profile was similar to that in men with no impairment of renal or hepatic function. Overdose with sildenafil was rare in the ED population. No new safety issues, emerging trends or adverse reactions were identified in conjunction with overdose, dependence, abuse or misuse. CONCLUSION This collated review confirms generally the good tolerability and established safety profile of sildenafil 50 and 100 mg in men with ED and reveals no new safety issues.
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Affiliation(s)
- F Giuliano
- AP-HP, Neuro-Uro-Andrology, Department of Physical Medicine and Rehabilitation, Raymond Poincaré Hospital, Garches, France.
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Eardley I, Donatucci C, Corbin J, El-Meliegy A, Hatzimouratidis K, McVary K, Munarriz R, Lee SW. Pharmacotherapy for Erectile Dysfunction. J Sex Med 2010; 7:524-40. [DOI: 10.1111/j.1743-6109.2009.01627.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Schlindwein P, Eicke BM, Stoeter P, Dieterich M. Sildenafil improves scotoma after posterior cerebral infarctions: a case report. J Neurol 2009; 257:674-7. [PMID: 20037762 DOI: 10.1007/s00415-009-5434-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2009] [Revised: 11/19/2009] [Accepted: 12/16/2009] [Indexed: 11/25/2022]
Abstract
A 65-year-old man had an embolic stroke of both posterior cerebral arteries in 2002. Two years later he noted rapid improvement of the residual bilateral inferior quadrant anopia whenever he took 25 mg sildenafil. The improvement of scotomas was verified by visual field examinations and persisted reproducibly for 3-7 days. An overlay of a subtraction of functional magnetic resonance imaging (MRI) during visual stimulation before and after medication onto a T1-weighted MRI of the patient revealed additional activations along the margins of the old cerebral infarctions. These findings and the additional results of a perfusion MRI suggest that phosphodiesterase 5 inhibitors may prove beneficial in the rehabilitative course after ischemic strokes.
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Low MY, Zeng Y, Li L, Ge XW, Lee R, Bloodworth BC, Koh HL. Safety and Quality Assessment of 175 Illegal Sexual Enhancement Products Seized in Red-Light Districts in Singapore. Drug Saf 2009; 32:1141-6. [DOI: 10.2165/11316690-000000000-00000] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Barren B, Gakhar L, Muradov H, Boyd KK, Ramaswamy S, Artemyev NO. Structural basis of phosphodiesterase 6 inhibition by the C-terminal region of the gamma-subunit. EMBO J 2009; 28:3613-22. [PMID: 19798052 DOI: 10.1038/emboj.2009.284] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 08/24/2009] [Indexed: 02/02/2023] Open
Abstract
The inhibitory interaction of phosphodiesterase-6 (PDE6) with its gamma-subunit (Pgamma) is pivotal in vertebrate phototransduction. Here, crystal structures of a chimaeric PDE5/PDE6 catalytic domain (PDE5/6cd) complexed with sildenafil or 3-isobutyl-1-methylxanthine and the Pgamma-inhibitory peptide Pgamma(70-87) have been determined at 2.9 and 3.0 A, respectively. These structures show the determinants and the mechanism of the PDE6 inhibition by Pgamma and suggest the conformational change of Pgamma on transducin activation. Two variable H- and M-loops of PDE5/6cd form a distinct interface that contributes to the Pgamma-binding site. This allows the Pgamma C-terminus to fit into the opening of the catalytic pocket, blocking cGMP access to the active site. Our analysis suggests that disruption of the H-M loop interface and Pgamma-binding site is a molecular cause of retinal degeneration in atrd3 mice. Comparison of the two PDE5/6cd structures shows an overlap between the sildenafil and Pgamma(70-87)-binding sites, thereby providing critical insights into the side effects of PDE5 inhibitors on vision.
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Affiliation(s)
- Brandy Barren
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
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Porst H, Hell-Momeni K, Büttner H. Chronische PDE-5-Hemmung bei erektiler Dysfunktion. Urologe A 2009; 48:1318, 1320-9. [DOI: 10.1007/s00120-009-2089-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Ponizovsky AM, Averbuch L, Radomislensky I, Grinshpoon A. A multicenter, randomized, open-labeled, parallel group trial of sildenafil in alcohol-associated erectile dysfunction: the impact on psychosocial outcomes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2009; 6:2510-25. [PMID: 19826560 PMCID: PMC2760426 DOI: 10.3390/ijerph6092510] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Accepted: 09/22/2009] [Indexed: 11/17/2022]
Abstract
To examine the effect of sildenafil on erectile dysfunction (ED) and psychosocial outcomes in alcohol-dependent (AD) men, 108 men with these diagnoses were randomly assigned to either take sildenafil (50 mg) as add-on to standard treatment for AD, or the same treatment without sildenafil, for 12 weeks. Only 50 patients in sildenafil group and 51 in control group twice completed the International Index of Erectile Function (IIEF) and a battery of self-report questionnaires. IIEF scores and psychosocial functioning, self-esteem and support from friends improved only for sildenafil-treated patients (P < 0.001). The high effect sizes suggest that the observed benefits are unlikely to be a placebo effect, although their unspecific nature could not be ruled out. In men with ED associated with AD, sildenafil improves both ED and psychosocial outcomes. Further placebo-controlled clinical trial is warranted.
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Affiliation(s)
- Alexander M. Ponizovsky
- Mental Health Services, Ministry of Health, 2 Ben Tabai St., Jerusalem 93591, Israel; E-Mail:
| | - Lev Averbuch
- The Department of Substance Dependence Treatment, Ministry of Health, 20 King David St., Jerusalem 91010, Israel; E-Mail:
| | - Ira Radomislensky
- Mental Health Services, Ministry of Health, 2 Ben Tabai St., Jerusalem 93591, Israel; E-Mail:
| | - Alexander Grinshpoon
- Tirat Carmel Mental Health Center, Ministry of Health, 17 Ha’ela St., ‘Tirat Carmel 30200, Israel Sha’ar Menashe Mental Health Center, Ministry of Health, Mobile Post Hefer 37806, Israel; E-Mail:
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Acaroglu G, Akinci A, Zilelioĝlu O. Sildenafil Associated Pupil-Sparing Third Nerve Palsy. Neuroophthalmology 2009. [DOI: 10.1080/01658100600981063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Hackett G, Kell P, Ralph D, Dean J, Price D, Speakman M, Wylie K. British Society for Sexual Medicine guidelines on the management of erectile dysfunction. J Sex Med 2008; 5:1841-65. [PMID: 18298470 DOI: 10.1111/j.1743-6109.2008.00773.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
INTRODUCTION UK primary care physicians are required to follow authoritative endorsed guidelines as part of their terms of service. The major influence on the management of erectile dysfunction in primary and secondary care between 1999 and 2007 has been Department of Health "guidance on good practice," a non-evidence-based document, essentially defining patients who qualify for government-funded treatment. AIM To provide clinically based guidelines relevant to UK primary and secondary healthcare professionals in their daily practice. METHODS A multidisciplinary panel of seven UK experts including two primary care physicians from the British Society for Sexual Medicine met for two full day meetings between September 2006 and April 2007, with each member allocated to disease areas related to their specialty. Feedback and approval of all sections between panel members was facilitated by the chairman. Source information was obtained from peer reviewed articles, meetings and presentations. Articles were chosen from electronically searching the Cochrane Library, Medline and Embase for randomized controlled clinical trials and graded according to level of evidence. RESULTS Patient-reported sexual activity, satisfaction with sexual activity (Male Sexual Health Questionnaire), and treatment expectations; urologists' subjective assessment of the importance given by their patients to ED; the timing they propose for starting ED treatment. RESULTS After the second full day meeting in January 2007, the final version was approved by panel members and made available for healthcare professions by download from http://www.bssm.org and from http://www.eguidelines.co.uk CONCLUSIONS A comprehensive evidence-based guideline has been developed that is highly relevant for primary and secondary care professionals enabling them to work within the unique requirements of the UK healthcare system.
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Hatzimouratidis K. Phosphodiesterase type 5 inhibitors, visual changes, and nonarteritic anterior ischemic optic neuropathy: Is there a link? Curr Urol Rep 2007; 8:482-90. [DOI: 10.1007/s11934-007-0053-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hellstrom WJG. Current safety and tolerability issues in men with erectile dysfunction receiving PDE5 inhibitors. Int J Clin Pract 2007; 61:1547-54. [PMID: 17655683 DOI: 10.1111/j.1742-1241.2007.01482.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
AIMS Treatment of erectile dysfunction (ED) has been greatly advanced by the advent of phosphodiesterase type-5 (PDE5) inhibitors. Upon the introduction of these agents, their cardiovascular (CV) safety was a major concern, mainly due to their vasodilatory effects. We conducted an electronic literature review of data concerning the safety and tolerability issues of men with ED receiving PDE5 inhibitors. RESULTS Although safety concerns have been raised, evaluation of CV safety and related adverse events in clinical trials has not revealed any atypical safety issues. DISCUSSION No causal association has been established to date between non-arteritic anterior ischaemic optic neuropathy (NAION) and PDE5 inhibitors. In addition, there are established guidelines which provide recommendations for the safe and effective use of these agents in treating men with ED and associated comorbidities. CONCLUSIONS Clinical trial and postmarketing surveillance data confirm the safety and tolerability profile of the PDE5 inhibitors, even in patients with endothelial dysfunction-associated comorbidities.
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Affiliation(s)
- W J G Hellstrom
- Section of Andrology & Male Infertility, Department of Urology, Tulane University Health Sciences Center, New Orleans, LA 70112, USA.
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Foresta C, Caretta N, Zuccarello D, Poletti A, Biagioli A, Caretti L, Galan A. Expression of the PDE5 enzyme on human retinal tissue: new aspects of PDE5 inhibitors ocular side effects. Eye (Lond) 2007; 22:144-9. [PMID: 17585311 DOI: 10.1038/sj.eye.6702908] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE We tested the effect of two phosphodiesterase type-5 (PDE5) inhibitors, sildenafil and tadalafil, on ophthalmic artery (OA) blood flow velocity and investigated the presence of the PDE5 enzyme on human retinal tissue in comparison with the PDE6 enzyme localization. METHODS Using Colour Doppler ultrasonography (CDU) we investigated, in 30 healthy young subjects (27.8 years of age; range, 24.3-33.7 years), the effects of a single oral dose of sildenafil (100 mg), tadalafil (20 mg), and placebo on OA blood flow velocity. Western blot for PDE6 and PDE5 protein expression was performed on frozen samples of human retina, testis, sperm, skin, and corpus cavernosum. Immunohistochemistry was performed on two ocular globes from dead donors. RESULTS CDU showed a relationship between the administration of PDE5 inhibitors and OA blood flow velocity modifications in a time-dependent manner. Western blot and immunohistochemical analysis showed PDE6 and PDE5 presence in human retinal tissue and gave a map of its distribution. CONCLUSION We demonstrated that (a) tadalafil and sildenafil are able to modify the OA flux in a time-dependent manner; (b) the PDE5 enzyme is expressed on retinal and choroid vasculature (smooth muscle and endothelial cells), on ganglion and bipolar cells; (c) human retinal tissues express the PDE6 enzyme in the rod and cone photoreceptors; (d) visual side effects after PDE5 inhibitors administration may be linked to a specific effect on the PDE5 enzyme; and (e) the PDE5 enzyme may have a physiologic role on ganglion and bipolar cells that need to be further investigated.
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Affiliation(s)
- C Foresta
- Department of Histology, Microbiology and Medical Biotechnologies, University of Padova, Padova, Italy.
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Agostino PV, Plano SA, Golombek DA. Sildenafil accelerates reentrainment of circadian rhythms after advancing light schedules. Proc Natl Acad Sci U S A 2007; 104:9834-9. [PMID: 17519328 PMCID: PMC1887561 DOI: 10.1073/pnas.0703388104] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mammalian circadian rhythms are generated by a master clock located in the suprachiasmatic nuclei and entrained by light-activated signaling pathways. In hamsters, the mechanism responsible for light-induced phase advances involves the activation of guanylyl cyclase, cGMP and its related kinase (PKG). It is not completely known whether interference with this pathway affects entrainment of the clock, including adaptation to changing light schedules. Here we report that cGMP-specific phosphodiesterase 5 is present in the hamster suprachiasmatic nuclei, and administration of the inhibitor sildenafil (3.5 mg/kg, i.p.) enhances circadian responses to light and decreases the amount of time necessary for reentrainment after phase advances of the light-dark cycle. These results suggest that sildenafil may be useful for treatment of circadian adaptation to environmental changes, including transmeridian eastbound flight schedules.
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Affiliation(s)
- Patricia V. Agostino
- Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, 1876 Buenos Aires, Argentina
| | - Santiago A. Plano
- Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, 1876 Buenos Aires, Argentina
| | - Diego A. Golombek
- Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, 1876 Buenos Aires, Argentina
- *To whom correspondence should be addressed. E-mail:
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Mecklenburg L, Schraermeyer U. An overview on the toxic morphological changes in the retinal pigment epithelium after systemic compound administration. Toxicol Pathol 2007; 35:252-67. [PMID: 17366319 DOI: 10.1080/01926230601178199] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Many medications that are administered systemically for nonocular conditions may evoke ocular toxicological complications. Therefore, the eye is routinely investigated histopathologically in preclinical in vivo toxicity studies. The retinal pigment epithelium is a likely target for systemically administered compounds, since the underlying choroid is highly vascularized. The specialized pigment epithelium has numerous functions that all maintain the integrity and function of photoreceptors. Consequently, toxic effects on the pigment epithelium will eventually affect the neural retina. The potential of pigment epithelial cells to respond to toxic injury is limited, but a standardized terminology to describe its morphological changes does not exist in the scientific literature. Detailed morphologic analysis, however, might allow early detection of retinotoxicity and may provide evidence on the underlying pathomechanism. We here review toxic effects on the pigment epithelium focusing in particular on the morphology of toxic cell injury. Morphological changes comprise hypertrophy, intracytoplasmic accumulation of cellular components, loss of cell polarity, degeneration, metaplasia, and formation of subretinal membranes. Some of these changes are reversible whereas others are permanent, leading to impaired function of the pigment epithelium and eventually to photoreceptor loss and retinal atrophy.
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Affiliation(s)
- Lars Mecklenburg
- ALTANA Pharma AG, Institute of Preclinical Drug Safety, Hamburg, 22885, Germany.
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Lüke M, Szurman P, Schneider T, Lüke C. The effects of the phosphodiesterase type V inhibitor sildenafil on human and bovine retinal function in vitro. Graefes Arch Clin Exp Ophthalmol 2007; 245:1211-5. [PMID: 17345091 DOI: 10.1007/s00417-007-0562-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Revised: 02/02/2007] [Accepted: 02/17/2007] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND After the ingestion of sildenafil (Viagra), visual adverse events have been reported, possibly caused by an inhibition of the phototransduction cascade by sildenafil via phosphodiesterase (PDE 6). Therefore, we investigated the effects of sildenafil on photoreceptors and postsynaptic neurons of human and bovine retinas using the isolated superfused vertebrate retina technique. METHODS Human and bovine retina preparations were perfused with an oxygen preequilibrated standard solution. The electroretinogram (ERG) was recorded using Ag/AgCl electrodes. After recording stable ERG amplitudes, sildenafil was added to the solution for 45 min. Thereupon, the preparations were reperfused with standard solution for 240 min. RESULTS Following the application of sildenafil (3 microMol/l), the b-wave amplitude of bovine and human preparations was reduced continuously and disappeared completely. After reperfusion with the standard solution for 4 h, the b-wave amplitude did not recover completely. Using the same sildenafil concentration (3 microMol/l), the a-wave amplitude of the human retina was not totally abolished, but reduced to 21% of the initial amplitude and remained reduced at washout. For all retinal preparations, the implicit time of the ERG amplitudes remained significantly extended at the end of the washout. CONCLUSIONS Strong similarities were detected in the drug-induced changes of the ERG when comparing human and bovine retinas. The results suggest that sildenafil impairs retinal function at not only the level of the photoreceptors, but it also affects the neuronal network of the inner retina at concentrations of approximately 30-fold higher than at therapeutic plasma concentrations.
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Affiliation(s)
- Matthias Lüke
- Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, 50931 Köln, Germany.
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45
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Dündar SO. Visual loss associated with erectile dysfunction drugs. Can J Ophthalmol 2007. [DOI: 10.3129/can.j.ophthalmol.06-122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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46
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Fodale V, Di Pietro R, Santamaria S. Viagra, surgery and anesthesia: A dangerous cocktail with a risk of blindness. Med Hypotheses 2007; 68:880-2. [DOI: 10.1016/j.mehy.2006.08.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2006] [Accepted: 08/16/2006] [Indexed: 11/26/2022]
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47
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Park SS. Bilateral serous macular detachment in a woman on sildenafil for pulmonary hypertension. Retin Cases Brief Rep 2007; 1:274-276. [PMID: 25391001 DOI: 10.1097/icb.0b013e3180339d36] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
PURPOSE To report a case of bilateral serous macular detachment in a woman on sildenafil for pulmonary hypertension. METHODS Case report of a 52-year-old woman presenting with painless loss of vision bilaterally after starting sildenafil 1 month earlier for pulmonary hypertension. RESULTS Bilateral serous macular detachment with cystoid macular edema was noted on funduscopy and optical coherence tomography (OCT). Fluorescein angiography showed several pinpoint areas of faint leakage with pooling in late views. Vision subjectively normalized 1 week after discontinuing sildenafil. Funduscopy and OCT also normalized on follow-up examination. CONCLUSION Bilateral serous macular detachment can be associated with sildenafil use for pulmonary hypertension. Vision loss is reversible with prompt discontinuation of the drug.
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Affiliation(s)
- Susanna S Park
- From the Department of Ophthalmology & Vision Science, University of California Davis Medical Center, Sacramento
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Goldstein I. EDITORIAL: The Journal of Sexual Medicine in 2007: The Electronic Age. J Sex Med 2007; 4:1-3. [PMID: 17233771 DOI: 10.1111/j.1743-6109.2007.00392.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Affiliation(s)
- Patricia O'Malley
- Cardiology Services, Miami Valley Hospital, 1 Wyoming Street, Dayton, OH 45409, USA.
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Watt SJ, Primatesta P, Siegel R. Response to Tomsak, R. PDE5 inhibitors and permanent visual loss (Int J Impot Res 2005; 17: 547-549). Int J Impot Res 2006; 18:411; author reply 412. [PMID: 16819534 DOI: 10.1038/sj.ijir.3901451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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