Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sildenafil citrate improves erectile function in men with erectile dysfunction (ED) by selectively inhibiting cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), which is present in all vascular tissue. Sildenafil also has a weaker inhibitory action on PDE6, located in the rod and cone photoreceptors. Modest, transient visual symptoms, typically blue tinge to vision, increased brightness of lights, and blurry vision, have been reported with sildenafil use and occur more frequently at higher doses. Visual function studies in healthy subjects and in patients with eye disease suggest that sildenafil does not affect visual acuity, visual fields, and contrast sensitivity. Transient, mild impairment of color discrimination can occur around the time of peak plasma levels. Spontaneous postmarketing reports of visual adverse events, including nonarteritic anterior ischemic optic neuropathy (NAION), have been reported during the 7 years that sildenafil has been prescribed to more than 27 million men worldwide. However, because men with ED frequently have vascular risk factors that may also put them at increased risk for NAION, a causal relationship is difficult to establish. No consistent pattern has emerged to suggest any long-term effect of sildenafil on the retina or other structures of the eye or on the ocular circulation.
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PMID:Ocular safety in patients using sildenafil citrate therapy for erectile dysfunction. 1640 14

Sildenafil, a phosphodiesterase-5 inhibitor commonly used for erectile dysfunction, may also have a beneficial therapeutic effect in the treatment of stroke, subarachnoid hemorrhage, dementia, learning, and neurodegenerative disorders by enhancing angiogenesis and neurogenesis. It also favorably influences the nitric oxide-cyclic guanosine monophosphate pathways, which are involved in the pathogenesis of a number of neurological diseases. Its potential therapeutic role in the treatment of the neurological disorders mentioned above is still under preclinical investigation. Sildenafil is currently being used to treat erectile dysfunction in patients with multiple sclerosis, Parkinson disease, multisystem atrophy, and spinal cord injury by improving their neurologically related erectile dysfunction. Conversely, it has been implicated in a number of neurological problems, such as intracerebral hemorrhage, migraine, seizure, transient global amnesia, nonarteritic anterior ischemic optic neuropathy, macular degeneration, branch retinal artery occlusion, and ocular muscle palsies. Thus, preclinical and very limited clinical data suggest that sildenafil may have therapeutic potential in selected neurological disorders. However, numerous reports are available regarding neurological adverse events ascribed to the drug. Although sildenafil shows some promise as a therapeutic agent in selected neurological disorders, well-designed clinical trials are needed before the agent can be recommended for use in any neurological disorder.
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PMID:Role of sildenafil in neurological disorders. 1905 Apr 13

Commonly prescribed urologic medications can have significant ophthalmologic side effects. The existing information can be conflicting. We looked at alpha-blockers and intraoperative floppy iris syndrome (IFIS), phosphodiesterase type 5 (PDE5) inhibitors and non-arteritic ischemic optic neuropathy (NAION) and lastly anticholinergic medications and glaucoma. There is no conclusive scientific data on what to do if the risk of urinary retention is low to moderate, however, we recommend that patients having cataract surgery should stop alpha-blocker medications preoperatively. If there is a high risk of urinary retention, the alpha-blocker should not be withheld, with the active involvement of the ophthalmologist. The role of using 5 alpha-reductase inhibitors (5ARIs) can be considered. There is no convincing evidence that PDE5 inhibitors cause non-arteritic anterior ischemic optic neuropathy (NAION), but patients should be advised of the possible risk of visual loss, especially in patients with risk factors of ischemic heart disease. Acute angle closure glaucoma (AACG or closed angle glaucoma) is very rarely caused by anticholinergic medications in patients with narrow angle anterior eye chambers. However, these medications are safe in patients with open angle glaucoma or treated closed angle glaucoma. Urologists should inquire about the patient's glaucoma history from his/her ophthalmologist before starting an anticholinergic medication.
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PMID:Urologic medications and ophthalmologic side effects: a review. 2239 71

Neuro-ophthalmology focuses on the diagnosis and treatment of visual disorders related to the neurological system rather than the globe itself. Being a subspecialty of both neurology and ophthalmology, it requires specialized training and expertise in diseases of the eye, brain, nerves and muscles. Commonly encountered pathologies in neuro-ophthalmology include: optic neuropathies (such as optic neuritis and ischemic optic neuropathy), visual field loss (transient, constant, unexplained), transient visual loss, unspecified visual disturbances, diplopia, abnormal eye movements, thyroid eye disease, myasthenia gravis, anisocoria, and eyelid abnormalities. The current issue of "Harefuah" is dedicated to contemporary knowledge in neuro-opthalmology, and spans from studies of neuromyelitis optica (NMO), ischemic optic neuropathies, and optic neuropathies induced by phosphodiesterase inhibitors, to the management of sight-threatening carotid-cavernous fistulas, and more. These studies emphasize the importance of an interdisciplinary treatment team consisting of a neuro-ophthalmologist, a neuro-radiologist, and sometimes, even a neuro-surgeon. Such an approach may prove to be beneficial to the patient, by optimizing follow-up and treatment decisions. This issue emphasizes how a correct and timely diagnosis is of paramount significance in patients with neuro-ophthalmological disorders.
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PMID:[Neuro-ophthalmology: the eye as a window to the brain]. 2351 93

Erectile dysfunction medications such as sildenafil citrate (Viagra) or tadalafil (Cialis) are commonly prescribed worldwide. They are selective phosphodiesterase-5 inhibitor and partial phosphodiesterase-6 inhibitors causing smooth muscle relaxation in the corpus cavernosum, allowing penile vasodilatation and erection in response to sexual stimuli. Over the years, there have been an increasing number of case reports concerning patients who developed ischemic optic neuropathy soon after the ingestion of these drugs. Although a cause and effect relationship between usage of the drugs and the development of ischemic optic neuropathy is difficult to prove, it is common nowadays to advise patients, especially those suffering from diabetes, hypertension, and ischemic heart disease, regarding the potential risk of visual loss due to ischemic optic neuropathy and treatment with erectile dysfunction drugs. Patients who were diagnosed with ischemic optic neuropathy soon after the ingestion of these erectile dysfunction drugs should be warned about a similar event in their fellow eye and should be advised regarding drug discontinuation.
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PMID:[Non-arteritic anterior ischemic optic neuropathy associated with erectile dysfunction medications]. 2351 98

Erectile dysfunction (ED) has negative effects on quality of life. The first line of oral medication for this condition is phosphodiesterase type 5 inhibitors (PDE5I) including Tadalafil. Ocular complications associated with Tadalafil are rare and usually occurred in participant with known risk factors. In this report, we describe and review the related literature of development of nonarteritic anterior ischemic optic neuropathy -associated Tadalafil. A healthy nonsmoking 42-year-old male with a history of ED presented with acute onset of an inferior visual field defect on the right eye. Automated perimetry showed inferior altitudinal loss in the affected eye. The administration of Tadalafil was discontinued as a potential causative agent for this condition. During follow-up, neither improvement signs nor symptoms revealed.
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PMID:Anterior Ischemic Optic Neuropathy in a Patient with Erectile Dysfunction: Tadalafil as an Offending Medication. 3021 Dec 42

To provide information on the effects of phosphodiesterase type 5 (PDE5) inhibitors on choroidal vessels and central serous chorioretinopathy (CSC) and possible implications for development of exudative age-related macular degeneration (AMD). Two independent investigators conducted a qualitative review of PubMed to identify studies on the choroidal effect of PDE5 inhibitors in June 2019. The search used key words that included PDE5 inhibitors, sildenafil, tadalafil, vardenafil, choroid, choroidal flow, choroidal vessels, choroidal thickness, CSC, AMD or a combination. Only studies which assessed choroidal findings were included. Many ocular diseases are related to changes in choroidal thickness and perfusion. Patients with AMD, who have decreased choroidal perfusion, may manifest more severely diminished choroidal ability to deliver oxygen and other metabolites to the retina, leading to growth of neovascular tissue. As a result of this engorgement of the choroidal vasculature, some patients may have leakage across the retinal pigment epithelium (RPE) and accumulation of subretinal fluid, resulting in CSC. Transient visual symptoms, i.e., changes in color perception and increased light sensitivity, are well-known adverse effects, but there have been rare reports of vision-threatening ocular complications in users of PDE5 inhibitors, such as nonarteritic anterior ischemic optic neuropathy and cilioretinal artery occlusion. The choroid is a vascular tissue analogous in many respects to the corpus cavernosum, and PDE5 inhibitors may increase the choroidal thickness and perfusion. While it is intuitively obvious that thickness of the choroid alone does not guarantee better choriocapillaris oxygenation, it is a reasonable step towards ameliorating ischemia. These drugs have numerous physiologic effects on the choroid related to blood flow, such as clinical consequences in CSC and AMD.
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PMID:Effects of phosphodiesterase type 5 inhibitors on choroid and ocular vasculature: a literature review. 3278 24