The Glomerular Filtration Rate Estimators in the Pharmacokinetic Modelling in Acute Kidney Injury: An Observational Study.

The glomerular filtration rate (GFR), according to which the drug dose for patients with chronic kidney disease (CKD) is adjusted, is computed with estimators (eGFR) that are developed specifically for CKD. These particular types of estimators are also used in population pharmacokinetic (pop PK) modelling in drug development. Similar approaches without scientific validation have been proposed for patients with acute kidney injury (AKI), yet it is uncertain which specific eGFR should be used for drug dosing or in pop PK models in patients with AKI. In our study, we included 34 patients with AKI and vancomycin (VCM) treatment, and we built both individual PK and pop PK (non-linear mixed-effects, one-compartment) models to see which eGFR estimator is the best covariate. In these models different eGFRs (Cockcroft-Gault, MDRD, CKD-EPI 2009, Jelliffe and Jelliffe, Chen et al., and Yashiro et al. 2013) were used. We included six additional patients to validate the final pop PK model. All eGFRs underrate the true renal clearance in the AKI, so we created pop PK models for VCM dosing in AKI with all eGFRs, to discover that the most accurate model was the one with the Cockcroft-Gault estimator. Since the eGFRs underestimate the true renal clearance in AKI, they are inaccurate for clinical drug dosing decisions, with the exception of the Cockcroft-Gault one, which is appropriate for the pop PK models intended for drug development purposes in AKI.

Possible Interaction between Dabigatran and Ranolazine in Patients with Renal Failure.

Dabigatran etexilate is a direct oral anticoagulant (thrombin inhibitor) used for the prevention of stroke and systemic thromboembolic events in patients with permanent atrial fibrillation; prevention of venous thromboembolic events and deep veins thrombosis; treatment and prevention of pulmonary embolism. Dabigatran is a relatively new drug, and as a result, its interactions with other medications and their significance are not fully known. A 72 years old male, having a medical history of heart and renal failure, was hospitalized for pneumonia treatment. The patient was taking several drugs, including dabigatran 150 mg twice daily and ranolazine 750 mg twice daily. His creatinine clearance was 45.22 mL/min, International Normalized Ratio (INR)-7.03. Dabigatran was discontinued. After 9 days, INR decreased to 1.33, and after 6 days, creatinine clearance increased to 64.39 mL/min. The patient was taking an adequate dosage of dabigatran, thus dabigatran was thought to be overdosed due to its interaction with ranolazine because dabigatran is a p-glycoprotein substrate, whereas ranolazine is the inhibitor of this transporter. Dabigatran and ranolazine should be used with caution in patients with renal failure. It is recommended to use smaller doses of both medications and observe coagulation parameters if needed.

Impact of the World Health Organization Pain Treatment Guidelines and the European Medicines Agency Safety Recommendations on Nonsteroidal Anti-Inflammatory Drug Use in Lithuania: An Observational Study.

Background and objective: Irrational use of nonsteroidal anti-inflammatory drugs (NSAIDs) is the main cause of adverse effects-associated hospitalizations among all medication groups leading to extremely increased costs for health care. Pharmacoepidemiological studies can partly reveal such issues and encourage further decisions. Therefore, the aim of our study was to evaluate the utilization of non-opioid analgesics (ATC classification N02B and M01A) in Lithuania, and to compare it with that of other Baltic and Scandinavian countries in terms of compliance to the WHO pain treatment guidelines and the EMA safety recommendations on NSAID use. Materials and methods: The dispensing data were obtained from the sales analysis software provider in the Baltic countries (SoftDent, Ltd., Kaunas, Lithuania); State Medicine Control Agencies of Lithuania, Latvia, and Estonia; Norwegian Prescription Database; Swedish Database for Medicines; and Danish Prescription Database. Data included the utilization of both prescription and over-the-counter drugs. Utilization was expressed in defined daily doses (DDD)/1000 inhabitants/day. Results: During the 11-year period, the utilization of drugs belonging to the N02B and M01A groups increased by 22.8%, from 58.37 in 2005 to 71.68 DDD/1000 inhabitants/day in 2016 in Lithuania. Contrary to the WHO guidelines on pain management, all Baltic countries were more likely to use NSAIDs than other analgesics and antipyretics: in 2015, the drugs of the M01A group were used 6.04, 5.79, and 6.11 times more than those of N02B in Lithuania, Estonia, and Latvia, respectively, whereas the Scandinavian countries preferred the N02B to the M01A group: in Denmark and Sweden, the utilization of other analgesics and antipyretics was 2.33 and 1.24, respectively, times higher than that of NSAIDs. In Norway, the use of both groups was similar. In the Scandinavian countries, paracetamol was the analgesic of first choice, whereas, in Lithuania, it took only the third place. The most popular drug in Lithuania was diclofenac, and its utilization accounted for 30.04% of all non-opioid analgesics in 2016. Although the European Medicines Agency (EMA) restricted the use of certain NSAIDs, i.e., cyclooxygenase-2 (COX-2) inhibitors, nimesulide, and diclofenac, their use consistently increased by 15.91, 2.83, and 1.41 times, respectively, showing incompliance with the international guidelines. Conclusions: Neither the EMA safety policy on NSAID use nor the WHO pain treatment guidelines had a sufficient impact on the rational use of NSAIDs in Lithuania. The use of NSAIDs restricted by the EMA (diclofenac, COX-2 inhibitors, nimesulide, and piroxicam) remains high or even increases, while the utilization of safer alternatives (paracetamol and naproxen) remains relatively low as compared with the Scandinavian countries. Incompliance with international guidelines may result in increased morbidity, mortality and higher costs for health care.

Comparison of the pharmacokinetic and pharmacodynamic properties of two recombinant granulocyte colony-stimulating factor formulations after single subcutaneous administration to healthy volunteers.

BACKGROUND AND OBJECTIVE: The aim of this randomized, single dose, two-period crossover study with two weeks wash-out period was the demonstration of bioequivalence of two recombinant human granulocyte colony-stimulating factor (rG-CSF) formulations after subcutaneous administration of 300µg comparing their pharmacokinetic (primary endpoints AUC0-24, AUC0-∞ and Cmax) and pharmacodynamic (primary endpoints ANC AUC0-72, ANC AUC0-∞ and ANCmax) profiles in healthy male subjects. MATERIALS AND METHODS: A total of 36 (23.0±6.0 years, 76.6±7.2kg) healthy subjects were recruited. Using a 1:1 randomization ratio, subjects were randomly assigned to one of two possible treatment-sequence groups to receive the single dose of test formulation (Gp-02) and reference product (Neupogen™) concentrations were measured by enzyme-linked immunosorbent assay (ELISA) up to 24h and the Absolute Neutrophil Count (ANC) was determined using hematology analyzer Coulter STKS™ (Beckman Coulter) up to 72h after injection. The geometric mean of primary pharmacokinetic and pharmacodynamic variables were considered bioequivalent if the 90% confidence intervals (CI) would fall in the bioequivalence range of 80%-125%. RESULTS: AUC0-24 (ratio of means 103.4, 90% CI: 95.6-111.9), AUC0-∞ (103.4, 90% CI: 95.7-111.7), Cmax (99.6, 90% CI: 89.0-111.4), ANC AUC0-72 (100.0, 90% CI: 96.6-103.5), ANC AUC0-∞ (100.8, 90% CI: 96.5-105.3), and ANCmax (100.2, 90% CI: 95.4-105.1) were determined. Single doses of test and reference formulations were well tolerated. The incidence of AEs was equally distributed across treatment groups with the most frequent AEs being headache, fever, and back pain. CONCLUSIONS: The study results demonstrated the bioequivalence of Gp-02, a new formulation of filgrastim, and the reference product Neupogen™.

Paracetamol and simvastatin: a potential interaction resulting in hepatotoxicity.

The safety profile of paracetamol and simvastatin is sufficiently well known, although no interactions between these two medicinal products have been described in the scientific literature so far. A 66-year-old female patient who experienced myocardial infarction and underwent coronary artery bypass grafting 9 years ago was taking simvastatin at a daily dose of 10 mg. Liver enzyme tests were carried out regularly, and their results were always normal. Later on, the patient took 6 tablets of fixed combination medicinal product Gripex(TM) (paracetamol, pseudoephedrine, and dextromethorphan) per day due to a fever. The daily dose of paracetamol taken by the patient totaled 1.95 g. The patient developed severe jaundice, nausea, vomiting; blood bilirubin levels increased more than 3 times; alanine transaminase, more than 10 times; and asparagine transaminase, more than 5 times. Paracetamol is metabolized by CYP enzymes (CYP2E1, 1A2, 2A6, 3A4) to a reactive metabolite, N-acetyl-p-benzoquinone-imine (NAPQI). Under conditions of excessive NAPQI formation or reduction in glutathione stores by approximately 70%, NAPQI covalently binds to the cysteinyl sulfhydryl groups of cellular proteins, forming NAPQI-protein adducts. Simvastatin is a substrate of CYP3A4 enzyme. Clinical and pharmacological data, available in the published literature, allow the assumption that simvastatin may induce CYP3A4 and result in increased hepatoxicity of paracetamol.

Efficacy, tolerability, and preference of mirtazapine orally disintegrating tablets in depressed patients: a 17-week naturalistic study in Lithuania.

Mirtazapine is an established antidepressant with well-documented efficacy demonstrated in controlled clinical trials. However, the gap between the results obtained in controlled clinical trials and everyday clinical practice exists. Therefore, the importance of naturalistic studies in psychiatry is becoming recognized. The aim of present naturalistic study was to acquire data on efficacy, safety, and preference of mirtazapine orally disintegrating tablets during a 17-week treatment of depression. This prospective, open-label, multicenter study in patients with mild to severe depression was conducted at 47 mental health centers of Lithuania by 78 psychiatrists. Patients were initially given 15 mg or 30 mg of mirtazapine orally disintegrating tablets; the maximum allowed dose was 45 mg per day. The primary efficacy measure was the total score on the Hamilton Depression Rating Scale-17 (HAMD-17), the Clinical Global Impression-Severity (CGI-S), and Clinical Global Impression-Improvement (CGI-I) scales. Tolerability was primarily measured by assessing the incidence of treatment-emergent adverse events. Patients were evaluated at baseline, at weeks 1, 5, 9, 13, and 17. A total of 779 patients (595 women [76.4%] with a mean [SD] age of 50.2 [13.65] and 184 men [23.6%] with a mean [SD] age of 52.4 [14.6] years) were enrolled into the study; 687 (88.2%) patients completed the study. The mean (SD) daily dose of mirtazapine orally disintegrating tablets was 29.0 (3.8) mg. The mean total (SD) HAMD-17 score improved significantly from 25.7 (4.6) to 7.3 (4.3) (P<0.005). At each visit, the mean HAMD-17 score was significantly lower than that at the preceding visit. At week 17, remission (HAMD-17 score < or =7) was observed in 436 (56%) patients. The mean (SD) CGI-S score improved significantly from 4.9 (1.0) at baseline to 1.5 (0.6) at endpoint (P<0.001). According to the CGI-I assessments, 621 patients (89.4%) improved and improved very much. The vast majority of patients (80%) preferred the new formulation of mirtazapine - mirtazapine orally disintegrating tablet. Treatment-emergent adverse events occurred in 106 patients (13.6%). The most frequent adverse events were weight gain, sedation, dizziness, and dry mouth. In this study conducted in Lithuania with depressed patients, a significant improvement was shown in all efficacy measures. In addition, mirtazapine orally disintegrating tablet was a well-tolerated and preferable formulation for the treatment of depressed patients.

[A case of severe hyponatremia in a patient suffering from epilepsy and using oxcarbazepine]. / Sunki hiponatremija, pasireiskusi pacientei, serganciai epilepsija bei vartojanciai okskarbazepina

A 70-year-old patient treated with oxcarbazepine experienced severe hyponatremia. The patient used oxcarbazepine (600 mg twice a day) concomitantly with diuretics (torasemide 10 mg and indapamide 1.25 mg once per day), perindopril, an angiotensin-converting enzyme inhibitor, and amlodipine, a Ca(2+) channel blocker. The patient complained of a nausea, malaise, diplopia, drowsiness, apathy, decreased diuresis (creatinine clearance - 41.51 ml/min), and exacerbation of epileptic seizures. Sodium concentration in the plasma was 113 mmol/l. The patient was hospitalized. It was suggested that a decrease in plasma sodium concentration was caused by oxcarbazepine used together with diuretics for six months. Oxcarbazepine-induced hyponatremia is reported in 22.2-50% of patients, although symptoms are present only in 5.9% of patients. The most common symptoms of central nervous system injury, experienced by patients, are drowsiness, dizziness, decreased cognitive function, coordination impairment, etc. Physicians not always in time pay proper attention to undesirable antiepileptic drug-induced effects, which can be dangerous.

[Nonsteroidal anti-inflammatory agents--choice between disturbances of gastrointestinal tract and cardiovascular toxicity]. / Nesteroidiniai vaistai nuo uzdegimo--pasirinkimas tarp zalingo poveikio virskinimo traktui bei galimo sirdies ir kraujagysliu pazeidimo.

Nonsteroidal anti-inflammatory agents are used more than 100 years. Most of them can cause undesirable effects on gastrointestinal tract: ulceration, bleeding and perforation of stomach and duodenum. Gastrointestinal toxicity is diminished when selective cyclooxygenase-2 inhibitors are used. However, recent clinical trials have showed that the use of cyclooxygenase-2 inhibitors increases the risk of cardiovascular event and cerebrovascular accident. According to the data such risk may be high using also nonselective nonsteroidal anti-inflammatory agents, however, it is lesser. Incidence rates of the cardiovascular events and cerebrovascular accidents increase due to activated thrombotic activity. Nonsteroidal anti-inflammatory agents are very useful in the management of rheumatic diseases and as pain relievers. Choosing appropriate nonsteroidal anti-inflammatory agent it is essential to consider the risk of gastrointestinal as well cardiovascular damage.

[Most common cases of the unreasonable medication use]. / Neracionalus vaistu vartojimas.

Doctors prescribing some medications together are often using unreasonable drug combinations. The rationality of prescribing the medications by means of case-records and computerized data base of the state sicknes fund was investigated. The article addresses the most common cases of unreasonable use of medications, which could be divided into five subgroups: 1) Prescribing drug combinations, that increase the possibility of side-effects; 2) Prescribing some medications, that may suppress the effects of each other together; 3) Using medications, that belong to the same group together; 4) Prescribing the medications either without indication or out of indication; 5) Other cases of the unreasonable medication use. This article discusses the risk of using most common drug combinations and provides recommendations that could help to prevent unreasonable medication use.