sildenafil-citrate and Cerebrovascular-Disorders

Sildenafil citrate is widely used for erectile dysfunction. The present study examined the short-term effects of sildenafil administration in individuals with cerebrovascular risk factors, including patients with a history of stroke.. Twenty-five consecutive male patients with erectile dysfunction and vascular risk factors were included in the study. A perfusion brain SPECT study was performed at baseline and 1 h after the oral administration of sildenafil.. Associations between any of the risk factors and the perfusion scores were not detected, with the exception of stroke. Stroke patients showed significantly more areas with diminished perfusion after sildenafil administration compared to baseline.. In patients with diabetes or hypertension, a dose of 50 mg sildenafil does not appear to produce detrimental effects on cerebral blood flow. However, patients with a history of stroke may be at increased risk of hemodynamic impairment after the use of sildenafil.

Topics: Adult; Aged; Brain Mapping; Cerebrovascular Circulation; Cerebrovascular Disorders; Erectile Dysfunction; Humans; Male; Middle Aged; Phosphodiesterase Inhibitors; Piperazines; Purines; Radiopharmaceuticals; Risk Factors; Sildenafil Citrate; Sulfones; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The present study evaluated the effects of sildenafil using the 4-vessel occlusion (VO)/internal carotid artery (ICA) model of chronic cerebral hypoperfusion (HCC). We previously found that permanent, three-stage occlusion of the vertebral arteries (VA) and ICA, four-VO/ICA, with an interstage interval (ISI) of 7 days was innocuous and caused no structural or functional outcomes in rats. Therefore, before testing sildenafil, we evaluated how a reduction in the number of occlusion stages (from three stages to two) and a shortening of the ISI might impact the survival rate, capacity for learning and memory, and histomorphological integrity of the hippocampus. Survival decreased from 100% to 70%, 62%, and 0% as the ISI was shortened from 7 to 5, 4, or 3 days, respectively. Using the two shortest ISIs, sildenafil (0.75-3.0 mg/kg, p.o.) abolished the mortality rate by approximately 95%. Profound neurodegeneration occurred in the CA1, CA2, CA3, and CA4 hippocampal subfields after an ISI of 4 days. Despite this, however, memory performance was unaffected. Subsequently, sildenafil treatment reduced 4-VO/ICA-induced hippocampal damage. The present results suggest that sildenafil may be potentially beneficial in the treatment of chronic cerebral hypoperfusion. Further studies should examine the manner by which the chronic 4-VO/ICA model may effectively cause cognitive impairment, thus improving its applicability in testing the effects of drugs against structural and/or functional outcomes of chronic cerebral hypoperfusion.

Topics: Animals; Carotid Artery Diseases; Cell Death; Cerebrovascular Disorders; Chronic Disease; Disease Models, Animal; Dose-Response Relationship, Drug; Hippocampus; Male; Maze Learning; Memory; Piperazines; Purines; Pyramidal Cells; Rats; Rats, Wistar; Sildenafil Citrate; Sulfones; Time Factors; Vasodilator Agents; Vertebrobasilar Insufficiency

To describe the magnetic resonance (MR) imaging findings associated with severe hypoglycemia after consumption of an illegal sexual enhancement product (Power 1 Walnut) adulterated with glibenclamide, an oral hypoglycemic agent used to treat diabetes mellitus.. Institutional review board approval was obtained for this retrospective study. Records in eight male patients with severe hypoglycemia of unknown cause, without prior treatment for diabetes, and with positive blood toxicology results for glibenclamide were reviewed. MR imaging included diffusion-weighted imaging and, in some patients, MR angiography, dynamic contrast material-enhanced perfusion MR imaging, and MR spectroscopy.. In seven patients, there were hyperintense abnormalities on diffusion-weighted and T2-weighted images in the hippocampus and cerebral cortex, sparing the subcortical white matter and cerebellum. Three patients had abnormalities of the splenium of the corpus callosum, and one had widespread involvement, including the caudate nucleus, basal ganglia, and internal capsule bilaterally. In three patients, unilateral cortical involvement, which did not conform to the typical cerebral arterial territories, was noted. In one patient, perfusion MR imaging showed slightly increased relative cerebral blood volume, and MR spectroscopy revealed no evidence of abnormal lactate in the affected cerebral cortex.. Diffusion-weighted MR imaging findings in patients with severe hypoglycemia showed typical lesions in the hippocampus and cerebral cortex, but the caudate nucleus and basal ganglia were involved in only the most severely affected patient. The splenium of the corpus callosum and internal capsule were also abnormal in three patients, and unilateral cortical lesions could be distinguished from acute ischemic stroke by the pattern of involvement and MR angiographic, perfusion, and spectroscopic findings.

Topics: Adult; Aged; Blood Volume; Brain; Cerebrovascular Disorders; Coma; Consciousness Disorders; Diffusion Magnetic Resonance Imaging; Dominance, Cerebral; Drug Contamination; Glasgow Coma Scale; Glyburide; Humans; Hypoglycemia; Hypoglycemic Agents; Illicit Drugs; Image Processing, Computer-Assisted; Lactic Acid; Magnetic Resonance Angiography; Magnetic Resonance Spectroscopy; Male; Middle Aged; Phytotherapy; Piperazines; Purines; Retrospective Studies; Seizures; Sildenafil Citrate; Sulfones; Vasodilator Agents

Topics: Cerebral Arteries; Cerebrovascular Circulation; Cerebrovascular Disorders; Endothelial Cells; Erectile Dysfunction; Humans; Male; Migraine Disorders; Patient Selection; Piperazines; Purines; Risk Assessment; Sildenafil Citrate; Sulfones; Vasodilation; Vasodilator Agents