Safety and Tolerability of High Doses of Glucocorticoides A

Safety and Tolerability of High Doses of Glucocorticoides A Branislava D. Rakić1,2, Jovanka L. Kolarović3, Nada V. Konstantinidis3, Velibor S. Čabarkapa4, Milan B. Ubavić2, Ana J. Sabo5, Aleksandar L. Rašković5 A 1 Medical Faculty, Department of Pharmacy, University of Novi Sad 2 Faculty of Pharmacy, University Business Academy in Novi Sad, , Novi Sad 3 Institute for Child and Youth Health Care of Vojvodina, Novi Sad 4 Department of Patophysiology, Faculty of Medicine, University of Novi Sad 5 Medical Faculty, Department of Pharmacology, toxicology and clinical pharmacology, University of Novi Sad A SUMMARY


INTRODUCTION
Acute lymphoblastic leukemia (ALL) is one of the most common malignancy in children and adolescents.It is a disease that occurs by malignant clonal proliferation of transformed lymphoid progenitors (leukemic lymphoblasts) that accumulate in the bone marrow, lymph nodes, liver, spleen and other organs [1].Th e most common symptoms are fatigue and lethargy, fever, pain in bones and joints.Synthetic steroids, prednisone and dexamethasone, represent part of ALL treatment in children [2].Th e treatment of ALL is based on the protocol of Berlin-Frankfurt-Munster group (BFM) and has four phases.Prednisone applies in the fi rst phase, while dexamethasone applies in second or in the third phase of the treatment [3].Compared with natural glucocorticoids, synthetic glucocorticoids have stronger pharmacological activity.By changing the structure (adding fl uorine atoms in the molecule) mineralocorticoid adverse eff ect is decreased.Glucocorticoid administration increases the number of circulating neutrophils, and reduces the number of lymphocytes (T and B), monocytes, eosinophils and basophils.A larger number of neutrophils is caused by their increased migration from the bone marrow, and also because of the reduced passage through the capillaries.Th is leads to the reduction of the number of neutrophils in the place of infl ammation [4].In comparison to prednisone, dexamethasone has better penetratation to the blood-brain barrier and into the bone marrow, resulting in a better therapeutic outcome (lower rate of relapse in the CNS and bone marrow).Some adverse eff ects of dexamethasone are stronger compared to the prednisone, but both glucocorticosteroids are used as part of the treatment protocol for leukemia [5][6][7][8].Common side eff ect of systemic administration of glucocorticoids is suppression of the adrenal cortex, which occurs by inhibition of corticotropin (ACTH) secretion.Th is is particularly evident if the therapy is administered over the long period of time (more than 7 days) and if it is abruptly stopped.Prevention of this adverse eff ect is achieved by a gradual dose reduction of these drugs [2].Iatrogenic Cushing's syndrome is also an adverse eff ect of glucocorticoid therapy.Due to the mineralocorticoid activity, usage of glucocorticoids leads to metabolic disorders of water and electrolytes, which result in water retention, hyponatremia, hypokalemia and hipochloremic alkalosis and high blood pressure.Th is side eff ects can limit the usage of these drugs [2,3].Glucocorticoids stimulate gluconeogenesis and glycogenolysis which can cause iatrogenic diabetes mellitus.Muscle weakness, loss of muscle mass and osteoporosis with concomitant risk of fractures are also common consequences of their application.Glucocorticoids inhibit release of growth hormone (even if it is administered in lower doses).Mental disorders such as euphoria, depression, psychosis, agitation and suicide, are also observed during the treatment of glucocorticoids [3,9].Glucocorticoids can cause a peptic ulcer disease due to the inhibition of arachidonic acid metabolism and prostaglandins, which protect mucous membrane in the stomach and duodenum from hydrochloric acid and bile salts [3].By suppressing of cellular immunity, glucocorticoids increase the tendency to fungal and viral infections [2,3,9].Considering that the administration of glucocorticoids signifi cantly increased therapeutic effi ciency of the protocol for the treatment of acute lymphoblastic leukemia in children potential toxicity of treatment is very important.Th e aim of this study was to analyze the adverse eff ects of high doses of corticosteroids in these patients.

SUBJECTS AND METHODS
Children aged 2 to 15 (9 boys and 9 girls) all treated according to the German BFM protocol in period from December 2010 to October 2014 were included in this observational prospective study upon having their parents' consent.Th e patients were treated in the Institute for Child and Youth Health Care of Vojvodina.Consent was obtained by the Ethics Committee of the Institute for Child and Youth Health Care.

RESULTS
Administration of glucocorticoids in children diagnosed with ALL caused the impairment in glucose regulation.Graph 1 shows the incidence of hyperglycemia aft er administration of prednisone and dexamethasone.Hyperglycemia occurred in 17 patients during administration of prednisone and in 11 patients during administration of dexamethasone.In 2 patients glucose blood level was higher than 10 mmol/L (which occurred during the application of dexamethasone) therefore insulin was administered.
High blood pressure (graph 2) was found in 5 patients during administration of prednisone and dexamethasone.Th e values of high blood pressure were within the range of 130/90 to 165/110 mmHg (according to www.hophonline.orgthe criteria for the classifi cation of hypertension according to the age of the child).In 3 patients, antihypertensive drugs (nifedipine, spironolactone and captopril) were applied.Spironolactone was applied to patient with hypertension and hypopotassemia.

The incidence of hypertension
Th e concentration of C-reactive protein (CRP) increased in 14 patients aft er prednisone administration (graph 3) from 9.5 to 238 mg/l, and in 9 patients treated with dexamethasone from 14.7 to 101 mg/l.CRP is one of the laboratory variables that indicates the presence of an infection.Saprophytic microorganism, staphylococcus and Candida species, which proliferated due to impairment of the immune system, were isolated in patients, and ceft riaxone, amikacin and fl uconazole were administered.Prednisone has lowered the concentration of potassium in 13 patients, whereas the usage of dexamethasone reduced this concentration in 5 patients (graph 4), and the value of this electrolyte were lower than 4 mmol/L.Hyponatremia, with values below 133 mmol/L, was observed in 9 patients during administration of prednisone, or in 10 patients during the application of dexamethasone.Prednisone reduced the concentration of calcium in 12 patients and dexamethasone in 5 patients (decreased values of calcium ranged from 1.3 to 2.13 mmol/L).
Prednisone has increased alanine aminotransferase (ALT) activity with an average value of 3.23 μkat/L ± 4.20 and dexamethasone has also incerased ALT with an average value of 2.86 μkat/L ± 2.26.Th is represents a 3.8 and 3.4 times higher values as compared to the upper reference value.In patients treated with prednisone and dexamethasone, an increase of aspartate aminotransferase (AST) in serum was also observed.Th e increase of AST activity aft er the administration of prednisone was 1.74 μkat/L ± 1.61 (2.9 times higher values), and aft er the administration of dexamethasone 2.24 μkat/L ± 2.07 (3.7 times higher values).Th e level of gamma-glutamyltransferase (GGT) was increased during the entire administration of glucocorticoids: 1.58 μkat/L ± 3.94 during prednisone treatment (4.3 times) and 0.77 μkat/L ± 0.38 on dexamethasone therapy (2.1 times).
Prednisone has aff ected the value of biochemical parameters in serum which indicated changes in renal function.Concentration of urea in serum was increased 1.34 times (8.08 mmol/L ± 1.17), and also concentration of uric acid was increased 1.53 times (452.53mmol/L ± 93.34).Elevation of values of these biochemical parameters were less during the application of dexamethasone (6.5 mmol/L ± 0 for urea and 352 mmol/L ± 0 for uric acid).During the application of dexamethasone psychological changes in two patients (one male and one female) were observed.Th ese changes manifested at fi rst with depression, and then with aggression, which occurred aft er corticosteroids saturate the organism.

DISCUSSION
Th e application of high doses of corticosteroids according to the protocols contributes to the success of the therapy because most of the lymphoblast have receptors for glucocorticoids, which prevent their proliferation.Using contemporary protocols for the treatment of ALL in children, about 80% of patients can be cured, which represents a signifi cant advancement in the treatment of malignant diseases in childhood [10].Since in these protocols, prednisone and dexamethasone applied in high doses, the incidence of adverse eff ects in patients were analyzed.
Chronic administration of glucocorticoids is associated with increased risk for glycemic disorders and the occurrence of iatrogenic diabetes.In this study, patients who were treated with prednisone had a higher incidence of reversible hyperglycemia as compared to patients who received dexamethasone.Studies by other authors (Bostrom et al, 2003) suggest that dexamethasone has a greater potential to cause disturbance of glycemic control compared to prednisone [11].According to the literature, hyperglycemia is usually resolved spontaneously during 48 hours aft er the treatment with glucocorticoids [12].In our study, aft er administration of corticosteroids, hyperglycemia also disappeared spontaneously in 50% of patients a few days aft er discontinuation of therapy, but in 11% of patients insulin was administered.
Due to the mineralocorticoid action, glucocorticoids cause retention of sodium and water in the body, thus the hypertension is rather common [13,14].Th e data show that hypertensive eff ect is dose-dependent and high blood pressure occurs in 80% of patients during corticosteroid therapy [14,15,16].In our study, hypertension occurred in 28% of patients aft er the administration of prednisone and dexamethasone.For regulation the high blood pressure (determined by the criteria for the classifi cation of hypertension in children), in 17% of patients antihypertensive drugs (nifedipine, spironolactone and captopril) were applied [17].
Because of the suppressive eff ect on cellular immunity, prednisone and dexamethasone caused the occurrence of bacterial and fungal infections.Th ese conditions are manifested by febrility, however aft er the treatment with antibiotics (ceft riaxone and amikacin) and antifungal azoles (fl uconazole), disorders had been normalized.
Electrolyte metabolism disorder is expected adverse eff ect of glucocorticoids [4,9].In this study, the application of prednisone caused a greater decrease in potassium, sodium and calcium level, compared to dexamethasone.Th ese results are explained by the fact that the dexamethasone is fl uorinated glucocorticoid and does not have mineralocorticoid activity and electrolyte disturbances are expected more frequently aft er the application of non-fl uorinatedcorticosteroids.
In both BNF (British National Formulary) and Summary of Product Characteristics of the European Medicines Agency (EMA) there is not mentioned an increase in transaminases activity as adverse eff ect of prednisone and dexamethasone.However, the results of clinical trials, in which prednisone and dexamethasone were administered simultaneously with 6-mercaptopurine and methotrexate, suggest hepatotoxicity and increased activity of liver enzymes, most likely as a consequence of the application of cytostatics [12].Th e increase in activity of ALT, AST and GGT obtained in this study, are not typical side effects of antineoplastic drugs used according to the protocol [18][19][20][21], but could be explained as result of their concomitant application and interaction with prednisone and dexamethasone, as published in another studies [22,23].Information in the literature suggest that glucocorticoids may cause disorders of the values of urea and uric acid [9].In our study both prednisone and dexamethasone increased the concentration of these biochemical parameters.Th is disorder was more prominent during the application of prednisone, which can be explained with mineralocorticoid eff ects of this drug and reduction of the excretion of nitrogen compounds.
Agitation and psychological disorders are recognized complications that occur during the application of corticosteroids www.hophonline.org[24,25].Th e authors of clinical studies indicate that females have a higher risk of neurocognitive complications aft er therapy ALL [26][27][28], which was not the case in this study-complications were equally represented and in male and female patients.According to the results of other authors, dexamethasone more often causes psychiatric disorders compared to prednisone, primarily due to the greater liposolubility which increased the crossing of blood-brain barrier [29].In our study, psychological changes in patients were noticed only during the application of dexamethasone.Hostility, withdrawal, agitation, impulsiveness and refusal of contact with family or medical staff were also noticed.Corticosteroids inhibit the metabolism of arachidonic acid and the synthesis of prostaglandins that protect mucous membrane of the gastrointestinal tract, so their application is associated with the development of peptic ulcer disease, the increased gastrin secretion and reduction of protective mucus secretion [30].Consequently, patients in our study prophylactically obtained H2 histamine receptor blockers, proton pump inhibitors, and sucralfate.None of the patients did develop peptic ulcer, which is why this prophylaxis is considered very eff ective.

CONCLUSION
Dexamethasone and prednisone, administered in high doses in children with acute lymphoblastic leukemia were known and most oft en disappeared spontaneously aft er cessation of the treatment with corticosteroids.High doses of prednisone and dexamethasone, as part of the protocol for the treatment of ALL in children, had the greater benefi t compared to the risk of adverse reaction.
Dexamethasone 10 mg/m2/d, is given orally or intravenously in 3 single doses, on day: 1 -21.By day 22 taper down stepwise to withdrawal over 9 days by halving the dose every 3 days, giving the highest dose in the morning.Vincristine was administered as iv bolus at dose of 1.5 mg/m2/d (maximal singe dose 2 mg), concomitantly with doxorubicin 30 mg/m2/d given as 1 hour infusion on day: 8, 15, 22, 29. .E. coli L-asparaginase is given as intramuscular injection at dose of 10000 U/m2/d, on day: 8, 11, 15, 18 (4 doses).Dexamethason at dose 20 mg/m2/d (days 1-6) is given as part high dose chemotherapy blocks containing vincristine at standard, previously mentioned dose, high dose methotrexate 5g/m2 in 24 hour infusion on day 1, cyclophosphamide 200 mg/m2/d over 1 hour infusion, 5 doses 12 hour apart on day: 2 -4 and high dose cytarabine (2 g/ m2, two doses 12 hours apart on day 5).Blood pressure, psychologists' opinion and course of the disease were analyzed from the medical records of patients during the period of application of corticosteroids.Th e concentration of glucose, sodium, potassium, calcium, urea and creatinine in serum, as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT) levels were analyzed as well.

Graph 1 .Graph 2 .Graph 3 .
The incidence of hyperglycemia after the application of prednisone and dexamethasone in children with acute lymphoblastic leukemia The incidence of hypertension after application of prednisone and dexamethasone in children with acute lymphoblastic leukemia The frequency of increased CRP level after application of prednisone and dexamethasone in children with acute lymphoblastic leukemia

4 .
The incidence of lower concentrations of potassium, sodium and calcium after application of prednisone and dexamethasone in children with acute