The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform
Saraswathy Laya - One of the best experts on this subject based on the ideXlab platform.
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Is 9β-dehydrohalogenation of betamethasone and dexamethasone hindering the detection of banned co-eluting Meprednisone? A reverse-phase chiral liquid chromatography high-resolution mass spectrometry approach.
Steroids, 2020Co-Authors: Tajudheen K. Karatt, M. Anwar Sathiq, Saraswathy LayaAbstract:Abstract Mass spectral analysis of dexamethasone and betamethasone reveal intense signals at m/z 373.19994 (using a Thermo Q Exactive high-resolution mass spectrometer coupled with Dionex UltiMate 3000 UHPLC + operated in the positive ion mode), matching the signal of Meprednisone, the 11-oxo version of methylprednisolone, along with its parent signal; possibly due to dehydrohalogenation of these drugs at MS. The parent mass of Meprednisone is exactly same as that of dehydrohalogenated mass of dexamethasone and betamethasone; and are co-eluting, displaying same mass spectra. Specifically when they are administered together, identifying Meprednisone (a drug for which there is zero tolerance in some regions of the world), is a great challenge with currently available techniques because it could be easily mistaken for dexamethasone or betamethasone, drugs allowed at certain threshold limits for therapeutic considerations. False negative results could be obtained in conventional reverse-phase chromatography and are liable to be abused; hence, establishing “zero tolerance” limits for these compounds often proves ineffective. In this paper, present an effective and reliable analytical method for simultaneously separating and identifying dexamethasone, betamethasone and Meprednisone in equine urine and plasma using chiral liquid chromatography-electrospray ionization-mass spectrometry. From the various columns screened, the Lux i-Cellulose-5 chiral column produced high-quality results with extremely good separation. During this study, it is quite evident that dehydrohalogenation occurs only in the mass ionization source; the compounds are very stable in-vivo/in-vitro and do not break down either on-column or during sample preparation.
Edgardo Cristiano - One of the best experts on this subject based on the ideXlab platform.
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Starting steroids dose, need for additional immunosuppression and long-term outcome in Myasthenia Gravis (P3.159)
Neurology, 2015Co-Authors: Marcelo Rugiero, Mariela Bettini, Marcelo Chaves, Maria Araoz, Edgardo CristianoAbstract:OBJECTIVE: Evaluate our therapeutic strategy regarding severity and age of MG patients, and if there are predictors of treatment response at disease onset. BACKGROUND: Steroids are first-line immunosuppressive treatment in Myasthenia Gravis (MG) and azathioprine the drug most widely used as additional immunosuppressive and steroid-sparing agent The majority of patients attain excellent disease control over time. However, there is little data on what proportion of patients reaches favorable status on low-dose immunotherapy. Some authors recommend starting treatment with high-dose steroids and add an additional immunosuppressive in elderly patients In our center, we begin a steroid treatment in a stepwise way according to clinical response, and postpone azathioprine due to clinical needs DESIGN/METHODS: MG generalized patients with a follow up >1year, who received steroids were included. We established as low dose 20 mg. MGFA status and PIS were used to assess severity. MGFA ≤ II was considered low initial status RESULTS: 48 MG patients were included. Mean time of follow up was 6 years (1-23y).56.3[percnt] was men, the mean age was 68 (18-88). 66.7[percnt] had autoantibodies against AchR . 60.4[percnt] required < 20mg of Meprednisone and 41.7[percnt] azathioprine in the follow up. There was no difference in initial MGFA status and age between patients who required high or low doses of steroids and /or azathioprine. PIS at first year were more severe in patients who received high dose of steroids and azathioprine. CONCLUSIONS: Approximately half of our MG patients can be managed with low-dose medication Initial MGFA seems to be not predictor of high dose of steroid or azathioprine requirement. PIS at first year are associated with more immunosuppression needs. This findings support that initial doses of steroids might be low regardless initial status. Study Supported by: Disclosure: Dr. rugiero has nothing to disclose. Dr. Bettini has nothing to disclose. Dr. Chaves has nothing to disclose. Dr. Araoz has nothing to disclose. Dr. Cristiano has received personal compensation for activities with Bayer, Biogen Idec, Merck & Co., Inc., and Novartis.
Guillermo Alberto Keller - One of the best experts on this subject based on the ideXlab platform.
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Severe Neutropenia in a Renal Transplant Patient Suggesting an Interaction Between Mycophenolate and Fenofibrate
Current drug safety, 2012Co-Authors: Paulino Alvarez, Jose Egozcue, Jihan Sleiman, Lucas Moretti, Guillermo Di Girolamo, Guillermo Alberto KellerAbstract:Objective: To describe a patient in whom initiation of micronized fenofibrate precipitated mycophenolate induced neutropenia. Case Summary: A 57-year-old man was admitted to the hospital because of febrile neutropenia. He had undergone kidney transplantation seventeen years ago. The patient's immunosuppressive maintenance regimen consisted of mycophenolate mofetil (MMF) 500 mg three times a day, and Meprednisone 4 mg daily. His medical history included, hypertension treated with losartan 50mg daily, and dyslipidemia treated with ezetimibe 10mg /simvastatin 20mg for four years (until 2 weeks before admission when micronized fenofibrate 200 mg per day was started because of persistently elevated triglycerides levels. On presentation temperature was 37.8oC and initial laboratory tests showed 3130 White Blood Cell Count(WBC)/μL with neutropenia (absolute neutrophil count (ANC) 313/μL) Fenofibrate and mycophenolate mofetil were discontinued, piperacillin tazobactam 4.5gr three times a day and granulocyte stimulation factor 300 μg/day were started. Three days after admission WBC was 7280/μL, neutrophils: 22%, ANC: 1160/mm3. Mycophenolate mofetil was restarted and granulocyte stimulation factor was discontinued. One month after discharge his WBC was 4480/μL and ANC 1926/μL. Discussion: The initiation of fenofibrate in a patient on stable and therapeutic doses of mycophenolate may have precipitated mycophenolate induced neutropenia, a well described, dose dependent phenomenon. Mycophenolic acid (MPA) displays a complex pharmacokinetic profile susceptible to potential significant interactions with fenofibrate. Since approximately 99% of MPA and fenofibrate bind to albumin, displacement may occur, leading to increased free MPA. Second competition of fenofibric acid for UGT1A9 an enzyme implicated in conjugation of MPA may have decreased its metabolism. The combination of these two effects may increase the risk of dose dependent neutropenia. Using the Interaction Probability Scale (DIPS), the interaction was designated as probable. Conclusions: Until further evidence is available, when fenofibrate is started in a renal transplant patient on mycophenolate careful monitoring should be considered to avoid potentially fatal complications.
Tajudheen K. Karatt - One of the best experts on this subject based on the ideXlab platform.
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Is 9β-dehydrohalogenation of betamethasone and dexamethasone hindering the detection of banned co-eluting Meprednisone? A reverse-phase chiral liquid chromatography high-resolution mass spectrometry approach.
Steroids, 2020Co-Authors: Tajudheen K. Karatt, M. Anwar Sathiq, Saraswathy LayaAbstract:Abstract Mass spectral analysis of dexamethasone and betamethasone reveal intense signals at m/z 373.19994 (using a Thermo Q Exactive high-resolution mass spectrometer coupled with Dionex UltiMate 3000 UHPLC + operated in the positive ion mode), matching the signal of Meprednisone, the 11-oxo version of methylprednisolone, along with its parent signal; possibly due to dehydrohalogenation of these drugs at MS. The parent mass of Meprednisone is exactly same as that of dehydrohalogenated mass of dexamethasone and betamethasone; and are co-eluting, displaying same mass spectra. Specifically when they are administered together, identifying Meprednisone (a drug for which there is zero tolerance in some regions of the world), is a great challenge with currently available techniques because it could be easily mistaken for dexamethasone or betamethasone, drugs allowed at certain threshold limits for therapeutic considerations. False negative results could be obtained in conventional reverse-phase chromatography and are liable to be abused; hence, establishing “zero tolerance” limits for these compounds often proves ineffective. In this paper, present an effective and reliable analytical method for simultaneously separating and identifying dexamethasone, betamethasone and Meprednisone in equine urine and plasma using chiral liquid chromatography-electrospray ionization-mass spectrometry. From the various columns screened, the Lux i-Cellulose-5 chiral column produced high-quality results with extremely good separation. During this study, it is quite evident that dehydrohalogenation occurs only in the mass ionization source; the compounds are very stable in-vivo/in-vitro and do not break down either on-column or during sample preparation.
Marcelo Rugiero - One of the best experts on this subject based on the ideXlab platform.
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Starting steroids dose, need for additional immunosuppression and long-term outcome in Myasthenia Gravis (P3.159)
Neurology, 2015Co-Authors: Marcelo Rugiero, Mariela Bettini, Marcelo Chaves, Maria Araoz, Edgardo CristianoAbstract:OBJECTIVE: Evaluate our therapeutic strategy regarding severity and age of MG patients, and if there are predictors of treatment response at disease onset. BACKGROUND: Steroids are first-line immunosuppressive treatment in Myasthenia Gravis (MG) and azathioprine the drug most widely used as additional immunosuppressive and steroid-sparing agent The majority of patients attain excellent disease control over time. However, there is little data on what proportion of patients reaches favorable status on low-dose immunotherapy. Some authors recommend starting treatment with high-dose steroids and add an additional immunosuppressive in elderly patients In our center, we begin a steroid treatment in a stepwise way according to clinical response, and postpone azathioprine due to clinical needs DESIGN/METHODS: MG generalized patients with a follow up >1year, who received steroids were included. We established as low dose 20 mg. MGFA status and PIS were used to assess severity. MGFA ≤ II was considered low initial status RESULTS: 48 MG patients were included. Mean time of follow up was 6 years (1-23y).56.3[percnt] was men, the mean age was 68 (18-88). 66.7[percnt] had autoantibodies against AchR . 60.4[percnt] required < 20mg of Meprednisone and 41.7[percnt] azathioprine in the follow up. There was no difference in initial MGFA status and age between patients who required high or low doses of steroids and /or azathioprine. PIS at first year were more severe in patients who received high dose of steroids and azathioprine. CONCLUSIONS: Approximately half of our MG patients can be managed with low-dose medication Initial MGFA seems to be not predictor of high dose of steroid or azathioprine requirement. PIS at first year are associated with more immunosuppression needs. This findings support that initial doses of steroids might be low regardless initial status. Study Supported by: Disclosure: Dr. rugiero has nothing to disclose. Dr. Bettini has nothing to disclose. Dr. Chaves has nothing to disclose. Dr. Araoz has nothing to disclose. Dr. Cristiano has received personal compensation for activities with Bayer, Biogen Idec, Merck & Co., Inc., and Novartis.