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PubMed2000

Early postnatal dexamethasone treatment and increased incidence of cerebral palsy.

OBJECTIVE: To study the long term neurodevelopmental outcome of children who participated in a randomised, double blind, placebo controlled study of early postnatal dexamethasone treatment for prevention of chronic lung disease. METHODS: The original study compared a three day course of dexamethasone (n = 132) with a saline placebo (n = 116) administered from before 12 hours of age in preterm infants, who were ventilated for respiratory distress syndrome and had received surfactant treatment. Dexamethasone treatment was associated with an increased incidence of hypertension, hyperglycaemia, and gastrointestinal haemorrhage and no reduction in either the incidence or severity of chronic lung disease or mortality. A total of 195 infants survived to discharge and five died later. Follow up data were obtained on 159 of 190 survivors at a mean (SD) age of 53 (18) months. RESULTS: No differences were found between the groups in terms of perinatal or neonatal course, antenatal steroid administration, severity of initial disease, or major neonatal morbidity. Dexamethasone treated children had a significantly higher incidence of cerebral palsy than those receiving placebo (39/80 (49%) v. 12/79 (15%) respectively; odds ratio (OR) 4.62, 95% confidence interval (95% CI) 2.38 to 8.98). The most common form of cerebral palsy was spastic diplegia (incidence 22/80 (28%) v. 5/79 (6%) in dexamethasone and placebo treated infants respectively; OR 4.45, 95% CI 1.95 to 10.15). Developmental delay was significantly more common in the dexamethasone treated group (44/80 (55%)) than in the placebo treated group (23/79 (29%); OR 2. 87, 95% CI 1.53 to 5.38). Dexamethasone treated infants had more periventricular leucomalacia and less intraventricular haemorrhage in the neonatal period than those in the placebo group, although these differences were not statistically significant. Eleven children with cerebral palsy had normal ultrasound scans in the neonatal period; all 11 had received dexamethasone. Logistic regression analysis showed both periventricular leucomalacia and drug assignment to dexamethasone to be highly significant predictors of abnormal neurological outcome. CONCLUSIONS: A three day course of dexamethasone administered shortly after birth in preterm infants with respiratory distress syndrome is associated with a significantly increased incidence of cerebral palsy and developmental delay.

Anti-Inflammatory Agents↗
PubMed2001

Mechanism of dexamethasone-mediated interleukin-8 gene suppression in cultured airway epithelial cells.

The effects of dexamethasone, a glucocorticoid analog, on interleukin 8 (IL-8) gene expression were studied in cultures of primary human tracheobronchial epithelial cells and an immortalized human bronchial epithelial cell line, HBE1 cells. Dexamethasone inhibited IL-8 mRNA and protein expression in a concentration- and time-dependent manner. The inhibition did not occur at the transcriptional level since both nuclear run-on activity and IL-8 promoter-reporter gene expression assay revealed no significant effect. Instead, there was a change in IL-8 mRNA stability in dexamethasone-treated cultures. Under actinomycin D treatment, IL-8 mRNA was quite stable in dexamethasone-depleted cultures, while in dexamethasone-pretreated cultures, IL-8 message was rapidly degraded within the first hour, then leveled off. When dexamethasone and actinomycin D were added simultaneously to dexamethasone-depleted cultures, IL-8 mRNA remained rather stable. When cycloheximide was used to inhibit new protein synthesis, dexamethasone-dependent inhibition was not observed. These results suggest that a posttranscriptional mechanism, which requires dexamethasone-dependent new protein synthesis, is involved in the regulation of IL-8 mRNA by dexamethasone in airway epithelial cells.

Cells, Cultured↗
PubMed2001

Modulation of alpha-ENaC and alpha1-Na+-K+-ATPase by cAMP and dexamethasone in alveolar epithelial cells.

cAMP and dexamethasone are known to modulate Na+ transport in epithelial cells. We investigated whether dibutyryl cAMP (DBcAMP) and dexamethasone modulate the mRNA expression of two key elements of the Na+ transport system in isolated rat alveolar epithelial cells: alpha-, beta-, and gamma-subunits of the epithelial Na+ channel (ENaC) and the alpha1- and beta1-subunits of Na+-K+-ATPase. The cells were treated for up to 48 h with DBcAMP or dexamethasone to assess their long-term impact on the steady-state level of ENaC and Na+-K+-ATPase mRNA. DBcAMP induced a twofold transient increase of alpha-ENaC and alpha1-Na+-K+-ATPase mRNA that peaked after 8 h of treatment. It also upregulated beta- and gamma-ENaC mRNA but not beta1-Na+-K+-ATPase mRNA. Dexamethasone augmented alpha-ENaC mRNA expression 4.4-fold in cells treated for 24 h and also upregulated beta- and gamma-ENaC mRNA. There was a 1.6-fold increase at 8 h of beta1-Na+-K+-ATPase mRNA but no significant modulation of alpha1-Na+-K+-ATPase mRNA expression. Because DBcAMP and dexamethasone did not increase the stability of alpha-ENaC mRNA, we cloned 3.2 kb of the 5' sequences flanking the mouse alpha-ENaC gene to study the impact of DBcAMP and dexamethasone on alpha-ENaC promoter activity. The promoter was able to drive basal expression of the chloramphenicol acetyltransferase (CAT) reporter gene in A549 cells. Dexamethasone increased the activity of the promoter by a factor of 5.9. To complete the study, the physiological effects of DBcAMP and dexamethasone were investigated by measuring transepithelial current in treated and control cells. DBcAMP and dexamethasone modulated transepithelial current with a time course reminiscent of the profile observed for alpha-ENaC mRNA expression. DBcAMP had a greater impact on transepithelial current (2.5-fold increase at 8 h) than dexamethasone (1.8-fold increase at 24 h). These results suggest that modulation of alpha-ENaC and Na+-K+-ATPase gene expression is one of the mechanisms that regulates Na+ transport in alveolar epithelial cells.

Animals↗
PubMed2004

Dexamethasone treatment in the newborn rat: fatty acid profiling of lung, brain, and serum lipids.

Dexamethasone is used as treatment for a variety of neonatal syndromes, including respiratory distress. The present study utilized the power of comprehensive lipid profiling to characterize changes in lipid metabolism in the neonatal lung and brain associated with dexamethasone treatment and also determined the interaction of dexamethasone with hypoxia. A 4-day tapering-dose regimen of dexamethasone was administered at 0800 on postnatal days 3 (0.5 mg/kg), 4 (0.25 mg/kg), 5 (0.125 mg/kg), and 6 (0.05 mg/kg). A subgroup of rats was exposed to hypoxia from birth to 7 days of age. Dexamethasone treatment elicited numerous specific changes in the lipid profile of the normoxic lung, such as increased concentrations of saturated fatty acids in the phosphatidylcholine and cholesterol ester classes. These increases were more profound in the lungs of hypoxic pups. Additional increases in cardiolipin concentrations were also measured in lungs of hypoxic pups treated with dexamethasone. We measured widespread increases in serum lipids after dexamethasone treatment, but the effects were not equivalent between normoxic and hypoxic pups. Dexamethasone treatment in hypoxic pups increased 20:4n6 and 22:6n3 concentrations in the free fatty acid class of the brain. Our results suggest that dexamethasone treatment in neonates elicits specific changes in lung lipid metabolism associated with surfactant production, independent of changes in serum lipids. These findings illustrate the benefits of dexamethasone on lung function but also raise the potential for negative effects due to hyperlipidemia and subtle changes in brain lipid metabolism.

Animals↗
PubMed1988

Effects of systemic and intracerebroventricular cysteamine on dexamethasone-induced suppression of corticosterone levels in the rat.

To investigate whether somatostatin systems plays a significant role in the regulation of the hypothalamic-pituitary-adrenal axis, the effects of cysteamine, a drug which reduces somatostatin levels, on the dexamethasone-induced suppression of plasma corticosterone levels were examined in the rat. Male Long Evans rats were handled daily for 1 week prior to receiving a standard dexamethasone suppression test. On the 1st day, rats received a 9.00 a.m. saline injection and blood samples were taken from the tail at 1.00 p.m. On the 2nd day, rats received dexamethasone or saline at 9.00 a.m. and a second blood sample was taken at 1.00 p.m. Experimental groups were pretreated with systemic injections of cysteamine, 5 min or 14 h, prior to receiving dexamethasone. Additional groups, previously implanted with guide cannulae, were given an infusion of cysteamine or saline into the lateral ventricle 14 h prior to dexamethasone. Circulating corticosterone levels were determined by radioimmunoassay. Rats were sacrificed immediately following each experiment and the hypothalamus dissected and assayed for levels of somatostatin immunoreactivity. The results of the first experiment showed that dexamethasone (10 micrograms/kg) alone reduced plasma corticosterone levels from control values (174 +/- 36 ng/ml) to undetectable levels (less than 25 ng/ml). Pretreatment with cysteamine 5 min prior to dexamethasone, while having no significant effect on basal corticosterone levels, completely blocked the dexamethasone-induced suppression of corticosterone levels. Similar observations were obtained with rats pretreated with cysteamine 14 h prior to dexamethasone. In contrast, intracerebroventricular cysteamine pretreatment did not block the dexamethasone-induced suppression of corticosterone levels. These results add further evidence in support of an involvement of somatostatin systems in the regulation of the hypothalamic-pituitary-adrenal axis.

Animals↗
PubMedDate not supplied

Ondansetron plus dexamethasone compared to the 'standard' metoclopramide combination.

This paper describes a multicentre, double-blind, parallel group study which compared ondansetron (0.15 mg/kg i.v. x 3) plus dexamethasone (20 mg i.v.) with metoclopramide (3 mg/kg i.v. x 2) plus dexamethasone (20 mg i.v.) and diphenhydramine (50 mg i.v.) for the prevention of cisplatin-induced emesis and nausea. Two hundred and eighty-nine consecutive patients receiving chemotherapy containing cisplatin at doses > or = 50 mg/m2 entered the study and 267 patients were evaluable for efficacy. The ondansetron regimen was significantly superior compared with the metoclopramide regimen in the control of acute emesis and nausea. Ondansetron plus dexamethasone provided complete protection against retching and vomiting in 79% of patients compared with 59% of patients given the metoclopramide combination (p < 0.002). Similarly ondansetron plus dexamethasone completely prevented nausea in 77% of patients, whereas the metoclopramide combination protected 66% of patients (p < 0.051). Success (no nausea and no emesis) was afforded to 69% of those patients given ondansetron plus dexamethasone as opposed to 50% of patients given the metoclopramide combination (p < 0.003). From day 2-4 all patients received the same anti-emetic regimen of oral metoclopramide and intramuscular dexamethasone. Significantly fewer patients who had received the ondansetron regimen on day 1 vomited on days 2 and 3 compared with those who had received the triple drug combination (84-86 and 68-71%, respectively, p < 0.006). Nausea was also better controlled in this group on day 2. On subsequent cisplatin cycles, the incidence of acute vomiting rose to 53% in those patients given the metoclopramide regimen, but remained low (26%) in the group treated with ondansetron plus dexamethasone. Patients receiving the metoclopramide regimen had significantly more sedation than patients receiving ondansetron plus dexamethasone (12 vs. 2%; p < 0.005). Extrapyramidal reactions were only observed in metoclopramide-treated patients (3%). The results of this study suggest that ondansetron plus dexamethasone is a more effective and better tolerated anti-emetic regimen compared with metoclopramide plus dexamethasone and diphenhydramine for the prevention of acute cisplatin-induced emesis.

Cisplatin↗
PubMed1991

Dexamethasone inhibits human interleukin 2 but not interleukin 2 receptor gene expression in vitro at the level of nuclear transcription.

Glucocorticosteroids have an inhibitory effect on the expression of interleukin 2 (IL-2) and interleukin 2 receptor (IL-2R) genes. To determine the mechanisms of this inhibition, human T lymphocytes were stimulated with mitogens in the presence of dexamethasone. Nuclear transcription run-off assays showed that high doses of dexamethasone inhibited the transcription of the IL-2 gene but not that of the IL-2R gene. Post-transcriptionally, high doses of dexamethasone (10(-4) M) were required to inhibit IL-2R mRNA levels by 50%, whereas lower doses (10(-6) M) inhibited by greater than 70% the accumulation of IL-2 mRNA. IL-2 mRNA half-life decreased in the presence of dexamethasone (10(-6) M) by approximately 50%. At the protein product level, dexamethasone inhibited both IL-2 production, as well as cell surface and soluble forms of IL-2R. IL-2R gene expression was inhibited for at least 72 h after exposure of cells to dexamethasone. In the presence of exogenous IL-2, dexamethasone failed to exert a significant effect on the production of IL-2R protein. These data indicate that dexamethasone has a greater effect on the expression of the IL-2 gene than on the IL-2R gene. Dexamethasone both inhibits transcription of the IL-2 gene and decreases the stability of IL-2 mRNA. The effect of dexamethasone on the IL-2R gene is post-transcriptional and may result indirectly from decreased IL-2 production.

Dexamethasone↗
PubMed1994

Local delivery of dexamethasone for prevention of neointimal proliferation in a rat model of balloon angioplasty.

A periadventitial polymer system is an alternative local drug delivery technique to obtain and maintain high tissue levels of the drug at the site of vascular injury. To determine if local periadventitial delivery of dexamethasone decreases neointimal proliferation after balloon vascular injury, in three groups of Sprague-Dawley rats, 5% dexamethasone, 0.5% dexamethasone, and placebo silicone polymers were implanted around the left common carotid artery after balloon injury. In a fourth group, placebo polymers were implanted without balloon injury. Dexamethasone serum and tissue levels after polymer implantation were significantly higher in the 5% dexamethasone group compared with the 0.5% dexamethasone group. There was no neointima formation in any of the arterial segments covered with placebo polymers for 3 wk, but without balloon injury. In the arterial segments covered by the 5 and 0.5% dexamethasone polymers, there was a 76 and 75% reduction in intima/media ratios, respectively, compared with the placebo group (5% dexamethasone, 0.26 +/- 0.04; 0.5% dexamethasone, 0.27 +/- 0.03; placebo, 1.09 +/- 0.16, respectively; P < 0.0001). These results suggest that: (a) silicone polymers wrapped around the common carotid arteries for 3 wk did not, without balloon injury, stimulate neointimal proliferation in the rat model; (b) the activity of the drug-eluting polymer for suppressing intimal proliferation was chiefly, but not exclusively, site specific; and (c) transadventitial local delivery of dexamethasone at two different doses markedly inhibits neointimal proliferation after balloon vascular injury.

Administration, Topical↗
PubMed2001

Cardiac adverse effects of early dexamethasone treatment in preterm infants: a randomized clinical trial.

This study evaluates the effects of early administration of dexamethasone on left ventricle dimensions and their clinical significance in preterm infants. Fifty preterm infants with birth weight < or = 1250 g and gestational age < or = 30 weeks were randomly assigned after 72 hours of life to the dexamethasone group (n = 25) or to the control group (n = 25). The treated infants received dexamethasone intravenously from the 4th day of life for 7 days (0.5 mg/kg/day for the first 3 days, 0.25 mg/kg/day for the next 3 days, and 0.125 mg/kg/day for the 7th day). Serial echocardiographic measurements of end systolic interventricular septum thickness, end diastolic interventricular septum thickness, end systolic left ventricle posterior wall thickness, end diastolic left ventricle posterior wall thickness, left ventricle end diastolic diameter, and left ventricle end systolic diameter were taken before starting dexamethasone, on days 3 and 7 of treatment, 7 days after the interruption of treatment, and at the 28th day of life. Five infants of each group were excluded by the final analysis because of the lack of a complete cardiac evaluation, leaving 20 treated and 20 control infants. Infants receiving dexamethasone had a significantly larger increase in mean septal and left posterior wall thickness during the treatment and 7 days after the dexamethasone weaning. The mean left ventricle diameter of treated infants was significantly lower than that of control infants from the 7th day of treatment to the 28th day of life. Four neonates (20%) in the dexamethasone group developed left ventricular myocardial hypertrophy without left ventricle outflow tract obstruction, showing signs of decreased cardiac output and ischemic changes on ECG. The daily fluid intake was increased to 200 ml/kg to ensure an adequate preload volume, and the complete resolution of left ventricle hypertrophy was obtained within the 2nd to 3rd week after dexamethasone weaning. Preterm infants receiving an early (< 96 hours of life) short course of dexamethasone develop a left ventricular myocardial hypertrophy that can be symptomatic and clinically significant. Preterm infants included in future studies with the goal to find the minimum dose and duration of dexamethasone treatment should be strictly monitored echocardiographically for this side effect.

Anti-Inflammatory Agents↗
PubMed1997

Phase III double-blind comparison of dolasetron mesylate and ondansetron and an evaluation of the additive role of dexamethasone in the prevention of acute and delayed nausea and vomiting due to moderately emetogenic chemotherapy.

PURPOSE: To compare the efficacy of dolasetron and ondansetron in controlling nausea and vomiting in the first 24 hours; to evaluate the efficacy when dexamethasone is added to either drug in the first 24 hours; and to extend these comparisons over 7 days in patients receiving moderately emetogenic chemotherapy. PATIENTS AND METHODS: This was a multicenter, double-blind, randomized study with six parallel arms that used a 2 x 2 factorial design in chemotherapy-naive patients. In arm 1, dolasetron (2.4 mg/kg) was given intravenously (I.V.) prechemotherapy, followed 24 hours later by oral dolasetron (200 mg once daily) for 6 days. Arms 2 and 3 consisted of dolasetron and dexamethasone 8 mg I.V., followed 24 hours later by oral dexamethasone (8 mg once daily) in one arm, and oral dexamethasone and dolasetron in the other, also for 6 days. In arms 4, 5, and 6, ondansetron (32 mg I.V. or 8 mg orally twice daily) was administered in a similar manner to arms 1, 2, and 3 before and 24 hours after chemotherapy. Mean nausea severity (MNS) was assessed on a visual analog scale (VAS) in a daily diary. RESULTS: Of 703 patients enrolled, 696 were eligible. There were 343 dolasetron- and 353 ondansetron-treated patients; 57% of dolasetron-treated patients had complete protection in the first 24 hours versus 67% of patients who received ondansetron (P = .013). MNS was also more pronounced on the dolasetron arm (P = .051). Sixty-seven percent of patients who received added dexamethasone in the first 24 hours had complete protection, compared with 55% without dexamethasone (P < .001). MNS was significantly reduced with the addition of dexamethasone (P < .001). At 7 days, dolasetron and ondansetron had equivalent complete protection rates (36% and 39%, respectively). With the addition of dexamethasone, 48% of patients compared with 28% had complete protection (P < .001). MNS was significantly improved with added dexamethasone (P < .001). CONCLUSION: At the doses used, dolasetron was significantly less effective than ondansetron at controlling nausea and vomiting in the first 24 hours in patients receiving moderately emetogenic chemotherapy, but there was no demonstrable difference between both drugs over 7 days. The addition of dexamethasone significantly improved the efficacy of both drugs in the first 24 hours and over 7 days.

Administration, Oral↗
PubMed1983

The effect of dexamethasone on renal potassium excretion and acute potassium tolerance.

In order to further characterize the kaliuretic action of dexamethasone, the effect of the hormone on renal electrolyte excretion and potassium tolerance was evaluated. In the first set of experiments, dexamethasone was administered acutely to unreplaced adrenalectomized rats, to adrenalectomized rats replaced with a single daily injection of dexamethasone (10 micrograms/100 g X day), and to intact control rats. After dexamethasone injection (10 micrograms/100 g), urinary potassium excretion increased by 105% in unreplaced adrenalectomized rats (0.99 +/- 0.13 to 2.02 +/- 0.26 mueq/min, P less than 0.005) and by 59% in rats maintained on glucocorticoid (0.87 +/- 0.10 to 1.38 +/- 0.18 mueq/min, P less than 0.05). The kaliuresis in adrenalectomized rats was associated with a significant increase in phosphate excretion and by a tendency for urinary chloride excretion to rise. In contrast, potassium excretion was unchanged by dexamethasone in control rats. These results indicate that the kaliuretic effect of dexamethasone is influenced by the degree of glucocorticoid deficiency before hormone administration. An additional study with K loading was performed in these same three groups of rats to evaluate the effect of dexamethasone replacement on potassium tolerance. Adrenalectomized rats maintained in daily dexamethasone replacement received an additional dose of hormone (50 micrograms/100 g) before study. After KCl, plasma potassium concentration rose significantly higher in unreplaced adrenalectomized rats vs. control (2.2 +/- 0.2 vs. 1.3 +/- 0.4 meq/liter, P less than 0.05) and peak renal potassium clearance was significantly blunted (577 +/- 90 vs. 1104 +/- 120 microliter/min. P less than 0.001). This impairment in potassium tolerance could not be attributed to hypotension, acidemia, diminished urinary flow, or sodium delivery in the distal nephron in unreplaced adrenalectomized rats but may be explained by decreased renal perfusion since glomerular filtration rate at the end of study was lower than in controls. Dexamethasone replacement improved potassium tolerance (peak delta Pk = 1.7 +/- 0.1 meq/liter) and renal potassium clearance (942 +/- 60 microliter/min). These data demonstrate that dexamethasone, at the high dose employed during KCl loading, improves renal potassium tolerance by enhancing renal K clearance in adrenalectomized rats. These results explain our previous report of near normal potassium excretion in glucocorticoid replaced adrenalectomized rats.

Adrenalectomy↗
PubMed2003

Discriminatory value of the low-dose dexamethasone suppression test in establishing the diagnosis and differential diagnosis of Cushing's syndrome.

Cushing's syndrome requires a screening test of high sensitivity, followed by biochemical evaluation of the source of the tumor when the cause is ACTH dependent. The high-dose dexamethasone suppression test is still in common use as an aid in differential diagnosis, although its value has been queried. We have routinely used the low-dose dexamethasone suppression test for many years in the diagnosis of Cushing's syndrome but noticed that patients with pituitary-dependent Cushing's syndrome or Cushing's disease, usually showed some degree of suppression of their serum cortisol, compared to those with the ectopic ACTH syndrome. We therefore analyzed retrospectively the serum cortisol responses during the low-dose dexamethasone suppression test and the high-dose dexamethasone suppression test in 245 patients with ACTH-dependent Cushing's syndrome and compared the diagnostic utility of each test either alone or in combination with a standard test using CRH. Evaluation of the serum cortisol response at 24 and 48 h during the low-dose dexamethasone suppression test correctly identified 98% of patients with ACTH-dependent Cushing's syndrome and distinguished between pituitary and ectopic causes with a sensitivity of 82% and a specificity of 79%. In the same patients, the serum cortisol response to the high-dose dexamethasone suppression test had a slightly higher sensitivity (91%) and specificity (80%). However, the combined criteria of a more than 30% suppression of serum cortisol during the low-dose dexamethasone suppression test and/or a more than 20% increase in the CRH test had a significantly higher sensitivity (97%) and specificity (94%) than either the high-dose dexamethasone or the CRH tests alone in the differential diagnosis of ACTH-dependent Cushing's syndrome. It produced equivalent information to that when high-dose and CRH test results were combined. We therefore conclude that in our patient series, the serum cortisol response during the low-dose dexamethasone suppression test is highly sensitive in diagnosing Cushing's syndrome and, combined with the results of the serum cortisol response to the CRH test, offered a safe and cost-effective test in the differential diagnosis of ACTH-dependent Cushing's syndrome. There does not appear to be any necessity for retaining the high-dose dexamethasone suppression test in this diagnostic work-up.

Adrenocorticotropic Hormone↗
PubMed2005

Dexamethasone: benefit and prejudice for patients undergoing on-pump coronary artery bypass grafting: a study on myocardial, pulmonary, renal, intestinal, and hepatic injury.

STUDY OBJECTIVES: Cardiac surgery with cardiopulmonary bypass (CPB) results in perioperative organ damage caused by the systemic inflammatory response syndrome (SIRS) and ischemia/reperfusion injury. Administration of corticosteroids before CPB has been demonstrated to inhibit the activation of the systemic inflammatory response. However, the clinical benefits of corticosteroid therapy are controversial. This study was designed to document the effects of dexamethasone on cytokine release and perioperative myocardial, pulmonary, renal, intestinal, and hepatic damage, as assessed by specific and sensitive biomarkers. DESIGN AND PATIENTS: A prospective, double-blind, placebo-controlled, randomized trial for dexamethasone was conducted in 20 patients receiving either dexamethasone (1 mg/kg before anesthesia induction and 0.5 mg/kg after 8 h; n = 10) or placebo (n = 10). Different markers were used to assess the SIRS: interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP), and tryptase; and organ damage: heart (plasma heart-type fatty acid binding protein, cardiac troponin I [cTnI], creatine kinase-MB), kidneys (N-acetyl-glucosaminidase [NAG], microalbuminuria), intestine (intestinal-type fatty acid binding protein [I-FABP]/liver-type fatty acid binding protein [L-FABP]), and liver (alpha-glutathione S-transferase). RESULTS: Dexamethasone modulated the SIRS with lower proinflammatory (IL-6, IL-8) and higher antiinflammatory (IL-10) IL levels. CRP and tryptase were lower in the dexamethasone group. cTnI values were lower in the dexamethasone group at 6 h in the ICU (p = 0.009). Patients in the dexamethasone group had a longer time to tracheal extubation (18.86 +/- 1.13 h vs 15.01 +/- 0.99 h, p = 0.02 [mean +/- SEM]), with a lower oxygenation index at that time: Pa(O2)/fraction of inspired oxygen ratio, 37.17 +/- 1.8 kPa vs 29.95 +/- 2.1 kPa (p = 0.009). The postoperative glucose level (10.7 +/- 0.6 mmol/L vs 7.4 +/- 0.5 mmol/L, p = 0.005) was higher in the dexamethasone group. Serum glucose was independently associated with intestinal injury (urine I-FABP peak, R2 = 42.5%, beta = 114.4 +/- 31.4, significant at p = 0.002; urine L-FABP peak, R2 = 47.3%, beta = 7,714.1 +/- 1,920.9, significant at p = 0.001) and renal injury (urine NAG, R2 = 32.1%, beta = 0.21 +/- 0.07, significant at p = 0.009). Tryptase peaks correlated negatively with peaks of intestinal and renal injury biomarkers. CONCLUSION: Even while inhibiting SIRS, dexamethasone treatment offered no protection against transient, subclinical, perioperative abdominal organ damage. Tryptase release could have a preconditioning effect, offering protection against perioperative intestinal and renal damage. Dexamethasone treatment resulted in more pronounced postoperative pulmonary dysfunction, prolonged time to tracheal extubation, and initiated postoperative hyperglycemia in patients undergoing elective on-pump coronary artery bypass graft surgery.

Anti-Inflammatory Agents↗
PubMed1998

Sensitivity of mononuclear leucocytes to glucocorticoids in elderly hip-fracture patients resistant to suppression of plasma cortisol by dexamethasone.

OBJECTIVE: Elderly women with proximal femur fracture show a prolonged increase in plasma cortisol, which could have undesirable catabolic effects. Suppression of cortisol by dexamethasone is impaired, suggesting resistance to glucocorticoid effects at feedback inhibitory sites. We therefore wished to find out whether peripheral glucocorticoid sensitivity is normal. DESIGN: Peripheral blood mononuclear leucocytes were used as a model tissue. Blood samples were taken from elderly women about 2 weeks after hip fracture and from elderly control women. Each patient was then given 1 mg dexamethasone at 2300 h followed by further sampling at 0800 and 1600 h the next day. METHODS: Glucocorticoid-receptor binding parameters were measured by incubating whole cells with [3H]dexamethasone for 2 h at 37 degrees C. Inhibition of cell proliferation by dexamethasone was assessed by addition of [3H]thymidine to cells cultured for 65 h with concanavalin A. Cortisol and dexamethasone concentrations were measured in the dexamethasone suppression test. RESULTS: As expected, the hip-fracture patients had raised morning cortisol concentrations and impaired suppression by dexamethasone. The cells of the patients had similar numbers of glucocorticoid receptors to those of the control subjects but higher values for Kd (i.e. a lower binding affinity). The cells of the patients incorporated less [3H]thymidine than the control cells in the absence of dexamethasone. The percentage inhibition by a saturating concentration of dexamethasone was unchanged but the concentration giving half-maximal inhibition was decreased (sensitivity was increased) at the higher of the two concanavalin A concentrations used. CONCLUSIONS: These experiments in mononuclear leucocytes give no evidence of peripheral resistance to glucocorticoids in hip-fracture patients with impaired suppression of cortisol by dexamethasone.

Aged↗
PubMed2002

A pulse of insulin and dexamethasone stimulates serum leptin in fasting human subjects.

OBJECTIVES: We have previously shown that dexamethasone increases serum leptin in fed but not in fasted human subjects. We hypothesized that insulin and/or glucose mediated the effect of food intake. The primary aim of this study was to determine whether the administration of a pulse of insulin with dexamethasone was sufficient to increase serum leptin in vivo in fasted human subjects. Whether the presence of transient hyperglycemia and the dose of insulin were important was tested as a secondary aim. METHODS: Twenty-nine normal subjects were studied. In experiment 1 (meal-like), a pulse of insulin (0.03 U/kg s.c.) and of dexamethasone (2 mg i.v.) was given, and the blood glucose transiently elevated to 50 mg/dl above baseline for the first 2 h. In experiments 2 and 3 (dose-response), the effect of two doses of insulin (0.03 U/kg in experiment 2 and 0.06 U/kg in experiment 3) was tested in combination with dexamethasone, this time without transient hyperglycemia. Nine subjects were studied under fasting conditions, with or without dexamethasone, as a control experiment. RESULTS: A meal-like transient hyperinsulinemia and hyperglycemia, with a pulse of dexamethasone, increased serum leptin levels from baseline by 54+/-21% at 9 h (P=0.038). In the absence of transient hyperglycemia, leptin increased significantly after doses of both insulin and dexamethasone. The effect of insulin was dose-dependent, with a larger increment of serum leptin at 9 h after the highest dose of insulin (75.2+/-15.7% vs 21.3+/-8.5%, P=0.013). Fasting, with or without dexamethasone, resulted in a significant 20% decrease in leptin from morning basal levels. Conversely, the administration of a pulse of insulin and glucose, in the absence of dexamethasone, prevented the drop in serum leptin observed during fasting, regardless of the insulin dose or the serum glucose elevation. CONCLUSIONS: With the permissive effect of dexamethasone, a single pulse of insulin triggered a rise in serum leptin in humans, even in the absence of transient hyperglycemia. A single pulse of insulin with glucose can prevent the drop in serum leptin normally observed during fasting.

Adult↗
PubMed1998

Early dexamethasone therapy in preterm infants: a follow-up study.

OBJECTIVES: To study the outcome at 2-year corrected age of infants who participated in a double-blind controlled trial of early (<12 hours) dexamethasone therapy for the prevention of chronic lung disease (CLD). METHODS AND MATERIALS: A total of 133 children (70 in the control group, 63 in the dexamethasone-treated group) who survived the initial study period and lived to 2 years of age were studied. All infants had birth weights of 500 to 1999 g and had severe respiratory distress syndrome requiring mechanical ventilation within 6 hours after birth. For infants in the treatment group, dexamethasone was started at a mean age of 8.1 hours and given 0.25 mg/kg every 12 hours for 1 week and then tapered off gradually over a 3-week period. The following variables were evaluated: interim medical history, socioeconomic background, physical growth, neurologic examinations, mental and psychomotor development index score (MDI and PDI), pulmonary function, electroencephalogram, and auditory and visual evoked potential. RESULTS: Infants in the control group tended to have a higher incidence of upper respiratory infection and rehospitalization than did the dexamethasone-treated group because of respiratory problems. Although there was no difference between the groups in somatic growth in girls, the dexamethasone-treated boys had significantly lower body weight and shorter height than the control boys (10.7 +/- 3.0 vs 11.9 +/- 2.0 kg; 84.9 +/- 5.7 vs 87.5 +/- 4.8 cm). The dexamethasone-treated group had a significantly higher incidence of neuromotor dysfunction (25/63 vs 12/70) than did the control group. The dexamethasone-treated infants also had a lower PDI score (79 +/- 26) than did the control group (87 +/- 23), but the difference was not statistically significant. Both groups were comparable in MDI, incidence of vision impairment, and auditory and visual evoked potential. Significant handicap, defined as severe neurologic defect and/or intellectual defect (MDI and/or PDI </= 69), was seen in 22 children (31.4%) in the control group and 26 (41.2%) in the dexamethasone-treated group. CONCLUSIONS: Although early postnatal dexamethasone therapy for 4 weeks significantly reduces the incidence of CLD, this therapeutic regimen cannot be recommended at present because of its adverse effects on neuromotor function and somatic growth in male infants, detected at 2 years of age. A longer follow-up is needed. If early dexamethasone therapy is to be used for the prevention of CLD, the therapeutic regimen should be modified. The proper route of administration, the critical time to initiate the therapy, and the dosage and duration of therapy remain to be defined further.

Child Development↗
PubMed1998

Three-year multicenter surveillance of pneumococcal meningitis in children: clinical characteristics, and outcome related to penicillin susceptibility and dexamethasone use.

OBJECTIVES: To evaluate the antibiotic susceptibility of Streptococcus pneumoniae isolates obtained from the blood and cerebrospinal fluid of children with meningitis. To describe and compare the clinical and microbiological characteristics, treatment, and outcome of children with meningitis caused by S pneumoniae based on antimicrobial susceptibility of isolates and the administration of dexamethasone. DESIGN AND PATIENTS: Children with pneumococcal meningitis were identified from among a group of patients with systemic infections caused by S pneumoniae who were enrolled prospectively in the United States Pediatric Multicenter Pneumococcal Surveillance Study at eight children's hospitals in the United States. From September 1, 1993 to August 31, 1996, 180 children with 181 episodes of pneumococcal meningitis were identified and data were collected by retrospective chart review. OUTCOME: Clinical and laboratory characteristics were assessed. All pneumococcal isolates were serotyped and antibiotic susceptibilities for penicillin and ceftriaxone were determined. Clinical presentation, hospital course, and outcome parameters at discharge were compared between children infected with penicillin-susceptible isolates and those with nonsusceptible isolates and for children who did and did not receive dexamethasone. RESULTS: Fourteen (7.7%) of 180 children died; none of the fatalities were because of a documented failure of treatment caused by a resistant strain. Only 1 child, who had mastoiditis and a lymphangioma, experienced a bacteriologic failure with a penicillin-resistant (minimum inhibitory concentration = 2 microgram/mL) organism. Of the 166 surviving children, 41 (25%) developed neurologic sequelae (motor deficits) and 48 (32%) of 151 children had unilateral (n = 26) or bilateral (n = 22) moderate to severe hearing loss at discharge. Overall, 12.7% and 6.6% of the pneumococcal isolates were intermediate and resistant to penicillin and 4.4% and 2.8% were intermediate and resistant to ceftriaxone, respectively. Clinical presentation, cerebrospinal fluid indices on admission, and hospital course, morbidity, and mortality rates were similar for patients infected with penicillin- or ceftriaxone-susceptible versus nonsusceptible organisms. However, the relatively small numbers of nonsusceptible isolates and the inclusion of vancomycin in the treatment regimen for the majority of the patients limit the power of this study to detect significant differences in outcome between patients infected with susceptible and nonsusceptible isolates. Nonetheless, our results show that the nonsusceptible organisms do not seem to be intrinsically more virulent. Forty children (22%) received dexamethasone (>/=8 doses) initiated before or within 1 hour after the first dose of antibiotics. The incidence of any moderate or severe hearing loss was significantly higher in the dexamethasone group (46%) compared with children not receiving any dexamethasone (23%). The incidence of any neurologic deficits, including hearing loss, also was significantly higher in the dexamethasone group (55% vs 33%). However, children in the dexamethasone group more frequently required intubation and mechanical ventilation and had lower initial concentration of glucose in the cerebrospinal fluid than children who did not receive any dexamethasone. When we controlled for the confounding factor, severity of illness (intubation), the incidence of any deafness and of any neurologic sequelae, including deafness, were no longer significantly different between children who did or did not receive dexamethasone. CONCLUSIONS: Children with pneumococcal meningitis caused by penicillin- or ceftriaxone-nonsusceptible organisms and those infected by susceptible strains had similar clinical presentation and outcome. The use of dexamethasone was not associated with a beneficial effect in this retrospective and nonrandomized study. (ABSTRACT TRUNCATED)

Adolescent↗
PubMed2000

Early dexamethasone-attempting to prevent chronic lung disease.

BACKGROUND: We previously demonstrated improved survival and early outcomes in a pilot trial of 2 doses of intravenous dexamethasone for infants with surfactant-treated respiratory distress syndrome. (1) A multicenter, randomized, double-blind trial was undertaken to confirm these results. METHODS: Infants <30 weeks' gestation were eligible if they had respiratory distress syndrome, required mechanical ventilation at 12 to 18 hours of age, and had received at least 1 dose of exogenous surfactant. Infants were excluded if sepsis or pneumonia was suspected or if congenital heart disease or chromosomal abnormalities were present. A total of 384 infants were enrolled-189 randomized to dexamethasone (.5mg/kg birth weight at 12-18 hours of age and a second dose 12 hours later) and 195 to an equal volume of saline placebo. RESULTS: No differences were found in the dexamethasone versus placebo groups, respectively, regarding the primary outcomes of survival (79% vs 83%), survival without oxygen at 36 weeks' corrected gestational age (CGA; both 59%), and survival without oxygen at 36 weeks' CGA and without late glucocorticoid therapy (46% vs 44%). No significant differences between the groups in estimates from Kaplan-Meier survival analyses were found for median days on oxygen (50 vs 56 days), ventilation (20 vs 27 days), days to regain birth weight (15.5 vs 14 days), or length of stay (LOS; 88 vs 89 days). Infants given early dexamethasone were less likely to receive later glucocorticoid therapy for bronchopulmonary dysplasia during their hospitalization (27% vs 35%). No clinically significant side effects were noted in the dexamethasone group, although there were transient elevations in blood glucose and blood pressure followed by a return to baseline by study day 10. Among infants who died (40 vs 33), there were no differences in the median days on oxygen, ventilation, nor LOS. However, in survivors (149 vs 162), the following were observed: median days on oxygen 37 versus 45 days, ventilation 14 versus 19 days, and LOS 79 versus 81 days, for the dexamethasone versus placebo groups, respectively. CONCLUSIONS: This dose of early intravenous dexamethasone did not reduce the requirement for oxygen at 36 weeks' CGA and survival was not improved. However, early dexamethasone reduced the use of later prolonged dexamethasone therapy, and among survivors, reduced the median days on oxygen and ventilation. We conclude that this course of early dexamethasone probably represents a near minimum dose for instituting a prophylactic regimen against bronchopulmonary dysplasia.

Bronchopulmonary Dysplasia↗