sildenafil-citrate and Pneumonia

Sildenafil is a selective and potent inhibitor of cyclic guanosine monophosphate specific phosphodiesterase-5 and has anti-inflammatory effects. The aim of the study was to evaluate the effects of sildenafil on smoke-induced lung inflammation.. Twenty-nine Wistar-Albino rats were enrolled into 3 groups as control, smoker and sildenafil groups. Smoker and sildenafil groups were exposed to cigarette smoke for 2 hours per day for 8 weeks. Sildenafil 10 mg/kg/day was administered to the sildenafil group by nasogastric lavage after smoke exposure. The degree of lung inflammation was scored histopathologically for each group.. The inflammation score was 7.25±0.93 in the control group, 8.18±1.21 in the smoker group and 7.08±1.66 in the sildenafil group. There was a non-significant decrease of inflammation score in sildenafil group with respect to control or smoker groups. While there was no significant difference of oedema, hyperemia, hemorrhage and mononuclear cell infiltration scores among the groups, it was found that the thickness of interalveolar septum and alveolar distortion was decreased in sildenafil group. However this decrease was not statistically significant.. This study suggests that sildenafil might reduce smoke-induced inflammation in rat lungs. Future studies are needed in order to investigate the clinical effectiveness of this finding in smoking related lung diseases.

Topics: Animals; Anti-Inflammatory Agents; Cytoprotection; Disease Models, Animal; Inhalation Exposure; Male; Phosphodiesterase 5 Inhibitors; Pneumonia; Pulmonary Alveoli; Rats, Wistar; Sildenafil Citrate; Smoke; Smoking

This study was performed to examine the effectiveness and safety of oral sildenafil and inhaled iloprost in term newborns with persistent pulmonary hypertension of the newborn (PPHN).. Oral sildenafil and inhaled iloprost were administered to 27 and 20 neonates, respectively, for treatment of persistent pulmonary hypertension. All patients were term infants at 37 gestational weeks or older. In the sildenafil group, 14 patients had meconium aspiration syndrome, 8 had asphyxia (hypoxic ischemic encephalopathy stages II and III), 3 had congenital pneumonia, 1 had transient tachypnea, and 1 had idiopathic PPHN. In the iloprost group, 9 patients had meconium aspiration syndrome, 7 had asphyxia (hypoxic ischemic encephalopathy stages II and III), 3 had congenital pneumonia, and 1 had transient tachypnea. Sildenafil citrate was administered via an oral feeding tube. Iloprost was administered endotracheally to patients on mechanical ventilation using a jet nebulizer.. Iloprost appeared to be more effective than sildenafil in the treatment of PPHN with regard to time to adequate clinical response, ventilatory parameters, duration of drug administration, duration of mechanical ventilation, duration of return to normal values of respiratory failure indices, use of MgSO4 as a second vasodilator and requirement for support with inotropic agents. We observed no side effects on blood pressure or homeostasis in any of the patients in the iloprost group. Systemic hypotension was significantly elevated in the sildenafil group. Four and three infants died of PPHN in the sildenafil and iloprost groups, respectively. Pulmonary systolic arterial pressure decreased to normal levels in the remaining 40 patients, and they were discharged from hospital.. We suggested that inhaled iloprost may be a safe and effective treatment choice in newborn infants with persistent pulmonary hypertension. In cases where treatment with inhaled iloprost, ECMO or INO is not possible, oral sildenafil can be an alternative therapy option in the treatment of PPHN.

Topics: Administration, Oral; Female; Humans; Hypertension, Pulmonary; Hypoxia-Ischemia, Brain; Iloprost; Infant, Newborn; Male; Meconium Aspiration Syndrome; Nebulizers and Vaporizers; Pneumonia; Retrospective Studies; Sildenafil Citrate; Tachypnea; Vasodilator Agents

Previous studies in rats have suggested a causal relationship between progressive pulmonary inflammation and lung fibrosis induced by crystalline silica particles. We report here that, in NMRI mice, the lung response to silica particles is accompanied by a mild and non progressive pulmonary inflammation which is dispensable for the development of lung fibrosis. We found that glucocorticoid (dexamethasone) dramatically reduced lung injury, cellular inflammation and pro-inflammatory cytokine expression (TNF-α, IL-1β and KC) but had no significant effect on silica-induced lung fibrosis and expression of the fibrogenic and suppressive cytokines TGF-β and IL-10 in mice. Other anti-inflammatory molecules such as the COX inhibitor piroxicam or the phosphodiesterase 5 inhibitor sildenafil also reduced lung inflammation without modifying collagen, TGF-β or IL-10 lung content. Our findings indicate that the development of lung fibrosis in silica-treated NMRI mice is not driven by inflammatory lung responses and suggest that suppressive cytokines may represent critical fibrotic factors and potential therapeutic targets in silicosis.

Topics: Animals; Bronchoalveolar Lavage Fluid; Cell Count; Collagen; Cyclooxygenase Inhibitors; Female; Interleukin-10; L-Lactate Dehydrogenase; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Phosphodiesterase 5 Inhibitors; Piperazines; Piroxicam; Pneumonia; Pulmonary Fibrosis; Purines; Sildenafil Citrate; Silicon Dioxide; Sulfones; Transforming Growth Factor beta

Phosphodiesterase-5 inhibition with sildenafil has been used to treat severe pulmonary hypertension and bronchopulmonary dysplasia (BPD), a chronic lung disease in very preterm infants who were mechanically ventilated for respiratory distress syndrome.. Sildenafil treatment was investigated in 2 models of experimental BPD: a lethal neonatal model, in which rat pups were continuously exposed to hyperoxia and treated daily with sildenafil (50-150 mg/kg body weight/day; injected subcutaneously) and a neonatal lung injury-recovery model in which rat pups were exposed to hyperoxia for 9 days, followed by 9 days of recovery in room air and started sildenafil treatment on day 6 of hyperoxia exposure. Parameters investigated include survival, histopathology, fibrin deposition, alveolar vascular leakage, right ventricular hypertrophy, and differential mRNA expression in lung and heart tissue.. Prophylactic treatment with an optimal dose of sildenafil (2 x 50 mg/kg/day) significantly increased lung cGMP levels, prolonged median survival, reduced fibrin deposition, total protein content in bronchoalveolar lavage fluid, inflammation and septum thickness. Treatment with sildenafil partially corrected the differential mRNA expression of amphiregulin, plasminogen activator inhibitor-1, fibroblast growth factor receptor-4 and vascular endothelial growth factor receptor-2 in the lung and of brain and c-type natriuretic peptides and the natriuretic peptide receptors NPR-A, -B, and -C in the right ventricle. In the lethal and injury-recovery model we demonstrated improved alveolarization and angiogenesis by attenuating mean linear intercept and arteriolar wall thickness and increasing pulmonary blood vessel density, and right ventricular hypertrophy (RVH).. Sildenafil treatment, started simultaneously with exposure to hyperoxia after birth, prolongs survival, increases pulmonary cGMP levels, reduces the pulmonary inflammatory response, fibrin deposition and RVH, and stimulates alveolarization. Initiation of sildenafil treatment after hyperoxic lung injury and continued during room air recovery improves alveolarization and restores pulmonary angiogenesis and RVH in experimental BPD.

Topics: Animals; Animals, Newborn; Disease Models, Animal; Fibrin; Humans; Hyperoxia; Hypertrophy, Right Ventricular; Lung Injury; Phosphodiesterase Inhibitors; Piperazines; Pneumonia; Purines; Rats; Rats, Wistar; Sildenafil Citrate; Sulfones; Survival Analysis; Survival Rate; Treatment Outcome