Snezana Djordjevic

Benzodiazepine poisoning in elderly

BACKGROUND/AIM Benzodiazepines are among the most frequently ingested drugs in self-poisonings. Elderly may be at greater risk compared with younger individuals due to impaired metabolism and increased sensitivity to benzodiazepines. The aim of this study was to assess toxicity of benzodiazepines in elderly attempted suicide. METHODS A retrospective study of consecutive presentations to hospital after self-poisoning with benzodiazepines was done. Collected data consisted of patients characteristics (age, gender), benzodiazepine ingested with its blood concentrations at admission, clinical findings including vital signs and Glasgow coma score, routine blood chemistry, complications of poisoning, details of management, length of hospital stay and outcome. According the age, patients are classified as young (15-40-year old), middle aged (41-65-year old) and elderly (older than 65). RESULTS During a 2-year observational period 387 patients were admitted because of pure benzodiazepine poisoning. The most frequently ingested drug was bromazepam, the second was diazepam. The incidence of coma was significantly higher, and the length of hospital stay significantly longer in elderly. Respiratory failure and aspiration pneumonia occurred more frequently in old age. Also, flumazenil was more frequently required in the group of elderly patients. CONCLUSION Massive benzodiazepines overdose in elderly may be associated with a significant morbidity, including deep coma with aspiration pneumonia, respiratory failure, and even death. Flumazenil is indicated more often to reduce CNS depression and prevent complications of prolonged unconsciousness, but supportive treatment and proper airway management of comatose patients is the mainstay of the treatment of acute benzodiazepine poisoning.

Corrosive and Cytotoxic Properties of Compact Specimens and Microparticles of Ni-Cr Dental Alloy

PURPOSE Nickel-chromium (Ni-Cr) dental alloys have been widely used in prosthodontic practice, but there is a permanent concern about their biocompatibility due to the release of metal ions. This is especially important when Ni-Cr metal microparticles are incorporated into gingival tissue during prosthodontic procedures. Therefore, the aim of this study was to examine and compare the corrosion and cytotoxic properties of compact specimens and microparticles of Ni-Cr dental alloy. MATERIALS AND METHODS Ni-Cr alloy, Remanium CSe bars (4 mm diameter), were made by the standard casting method and then cut into 0.5-mm-thick disks. Metal particles were obtained by scraping the bars using a diamond instrument for crown preparation. The microstructure was observed by an optical microscope. Quantitative determination and morphological and dimensional characterization of metal particles were carried out by a scanning electron microscope and Leica Application Suite software for image analysis. Corrosion was studied by conditioning the alloy specimens in the RPMI 1640 medium, containing 10% fetal calf serum in an incubator with 5% CO2 for 72 hours at 37°C. Inductively coupled plasma-optical emission spectrometry was used to assess metal ion release. The cytotoxity of conditioning medium (CM) was investigated on L929 cells using an MTT test. One-way ANOVA was used for statistical analysis. RESULTS After casting, the microstructure of the Remanium CSe compact specimen composed of Ni, Cr, Mo, Si, Fe, Al, and Co had a typical dendritic structure. Alloy microparticles had an irregular shape with a wide size range: from less than 1 μm to more than 100 μm. The release of metal ions, especially Ni and Mo from microparticles, was significantly higher, compared to the compact alloy specimen. The CM prepared from compact alloy was not cytotoxic at any tested dilutions, whereas CM from alloy microparticles showed dose-dependent cytotoxicity (90% CM and 45% CM versus control; p < 0.005). CONCLUSION Ni-Cr microparticles showed less corrosion resistance and lower biocompatibility than compact alloy. This could affect health on long-term exposure, especially in sensitized individuals.

Gastroprotective effects of novel antidotal combination in rats acutely poisoned by T-2 toxin

The purpose of this experiment was to evaluate the antidotal potencies of methylprednisolone (soluble form, Lemod-solu®), nimesulide, N-acetylcysteine (Fluimucil®) and their combinations in rats treated with 1.0 LD50 (0.23 mg/kg) of trichothecene mycotoxin, T-2 toxin. Their antidotal efficacy was investigated by monitoring their effects on general condition, 24-hour-survival, body weight gain, food and water consumption and pathohistological changes in the gut of Wistar rats acutely treated with a single injection of T-2 toxin during a 4-week period. The highest protective index was obtained with methylprednisolone (2.43). Initial loss of body weight (after first 7 days) was found only in T-2 toxin group. During the whole experiment, in poisoned rats protected by methylprednisolone or methylprednisolone and nimesulide, a significant increase (p<0.001) in body weight gain, food and water consumption in comparison with T-2 toxin group was found. At the end of the experiment, N-acetylcysteine, nimesulide and their combination assured higher (p<0.05) weight gain, food and water consumption in comparison with T-2 toxin group. Signs of hemorrhagic diathesis and necrosis of the gut crypt epithelium and lymphoid tissues were found in the T-2 toxin group. Some of these histological alterations were presented in the gut of poisoned rats treated by nimesulide, Nacetylcysteine and their combination. The gut of T-2 toxin rats treated with a combination of methylprednisolone and nimesulide and especially methylprednisolone alone had a histological structure similar to the control group. These results clearly show that methylprednisolone, a well-known anti-inflammatory and immunosuppressive drug, exerts the best antidotal effect against T-2 toxin intoxication in rats.

Determination of flumazenil in serum by liquid chromatography-mass spectrometry: Application to kinetics study in acute diazepam overdose.

BACKGOUND/AIM Flumazenil is benzodiazepine receptor antagonist. It has been studied for a various indications, including reversal of sedation after surgery or diagnostic procedures, awakening of comatose patients in benzodiazepine overdose, or for symptomatic treatment of hepatic encephalopathy. Some drugs, like theophylline, may prolong its elimination half-life. Considering the long half-life of diazepam and its metabolites, concomitant use of theophylline may reduce the need for repeated dosing of flumazenil in patients with acute diazepam poisoning. The aim of this study was to introduce a reliable and accurate method for determining the concentration of flumazenil after therapeutic application in patients with acute poisoning, and using that method to assess whether the kinetics of flumazenil change in the presence of aminophylline (combination of theophylline and ethylenediamine in a 2:1 ratio) applied as concomitant therapy. METHODS Blood samples from patients with acute diazepam poisoning that received flumazenil at the dose of 0.5 mg, or the same dose with 3 mg/kg of body weight of aminophylline, were collected 1, 3, 10, 30, 60, 120 and 240 min after its intravenous administration. Samples were prepared by solid-phase extraction on Oasis HLB cartridges with ethylacetate as extracting agens. Flumazenil was determined by liquid chromatography with mass spectrometry (LC-MS) in single ionmonitoring mode at m/z 304. Separation of flumazenil from matrix compound was performed on Lichrospher RP-8 column usingthe mixture of acidic acetonitrile and 20 mM of ammonium acetatein water (55 : 45) as a mobile phase. RESULTS The applied analitycal method showed excellent recovery (94.65%). The obtained extracts were much cleaner than the extracts obtained by the sameextractant in the process of liquid-liquid extraction. The limit ofdetection of the LC-MS method described in this paper was 0.5 ng/mL and the limit of quantitation was 1 ng/mL. In the patientstreated with both flumazenil and aminophylline, the eliminationconstant for flumazenil was significantly lower and the elimination half-life was longer (p < 0.05) in comparison with the same parameters in.the patients who received flumazenil alone. CONCLUSION The applied LC-MS method for the determination of flumazenil in serum samples of patients with acute diazepam poisoning is rapid, sensitive, precise and specific. Concomitant use with theophylline significantly prolonged elimination of flumazenil during the treatment of acute poisonings with diazepam.

Pharmacodynamic and pharmacokinetic effects of flumazenil and theophylline application in rats acutely intoxicated by diazepam

BACKGROUND/AIM The majority of symptoms and signs of acute diazepam poisoning are the consequence of its sedative effect on the CNS affecting selectively poli-synaptic routes by stimulating inhibitory action of GABA. The aim of the present study was to examine the effects of combined application of theophylline and flumazenil on sedation and impaired motor function activity in acute diazepam poisoning in rats. METHODS Male Wistar rats were divided in four main groups and treated as follows: group I--with increasing doses of diazepam in order to produce the highest level of sedation and motor activity impairment; group II--diazepam + different doses of flumazenil; group III--diazepam + different doses of theophylline; group IV--diazepam + combined application of theophylline and flumazenil. Concentrations of diazepam and its metabolites were measured with LC-MS. The experiment was performed on a commercial apparatus for spontaneous motor-activity registration (LKB-Farad, Sweden). Assessment of diazepam-induced neurotoxic effects and effects after theophylline and flumazenil application was performed with rotarod test on a commercial apparatus (Automatic treadmill for rats, Ugo Basile, Italy). RESULTS Diazepam in doses of 10 mg/kg and 15 mg/kg produced long-time and reproducible pharmacodynamic effects. Single application of flumazenil or theophylline antagonized effects of diazepam, but not completely. Combined application of flumazenile and theophylline resulted in best effects on diazepam-induced impairment of motoric activity and sedation. As a result of theopylline application there was better elimination of diazepam and its metabolites. CONCLUSION Combined application of flumazenil and theophylline resulted in the best antidotal effects in the treatment of diazepam poisoned rats. These effects are a result of different mechanisms of their action, longer half-life of theophylline in relation to that of flumezenil and presumably the diuretic effect of theophylline.