Chronic sildenafil citrate use decreases retinal vascular endothelial growth factor expression in diabetic rats: a pilot study

Pharmacological associations of central serous chorioretinopathy: Looking beyond corticosteroids

Central serous chorioretinopathy (CSCR) has multiple associations and risk factors. Of these, psychological stress, corticosteroid treatment, and specific personality traits are well recognized. Other drugs, such as sympathomimetic agents, psychotropic drugs and phosphodiesterase inhibitors, are frequently incriminated. Male preponderance and higher incidence among pregnant and menopausal women give credence to a role of gonadal hormones; however, the acceptance or rejection of the proposed role of other drugs remains challenging due to paucity of data resulting from low usage. Despite presence of multiple risk factors in several patients, a large proportion remains idiopathic. We reviewed all such drugs, including sympathomimetic drugs, psychotropic drugs and recreational agents, phosphodiesterase inhibitors, gonadal hormones and analogues, vasopressin, minoxidil, follistatin, fingolimod, topiramate, muscle relaxants, and vaccines. The mechanisms and adverse event profile of these drugs suggest multiple ways such as alteration of hypothalamic-pituitary-adrenal axis, cortisol surge, activation of sympathetic nervous system, nitric-oxide synthetase, proinflammatory cytokines, complement factor F, Cytochrome P450 3A4, voltage gated ion channels, connexins and neurotransmitters that eventually contribute to CSCR. A common denominator, however, is the systemic and choroidal hemodynamic changes. A detailed medication history can unravel the modifiable risk factors in idiopathic CSCR; this history must include drugs that alter the clearance of other drugs and hormones via the cytochrome P450-3A4 system.

Exploring the Multifaceted Potential of Sildenafil in Medicine

Phosphodiesterase type 5 (PDE5) is pivotal in cellular signalling, regulating cyclic guanosine monophosphate (cGMP) levels crucial for smooth muscle relaxation and vasodilation. By targeting cGMP for degradation, PDE5 inhibits sustained vasodilation. PDE5 operates in diverse anatomical regions, with its upregulation linked to various pathologies, including cancer and neurodegenerative diseases. Sildenafil, a selective PDE5 inhibitor, is prescribed for erectile dysfunction and pulmonary arterial hypertension. However, considering the extensive roles of PDE5, sildenafil might be useful in other pathologies. This review aims to comprehensively explore sildenafil's therapeutic potential across medicine, addressing a gap in the current literature. Recognising sildenafil's broader potential may unveil new treatment avenues, optimising existing approaches and broadening its clinical application.