Katarina Ilic

The relationship among hypertension, antihypertensive medications, and osteoporosis: a narrative review.

Osteoporosis and hypertension are two frequent diseases among the aging population that share a similar etiopathology and often coexist. Moreover, treatment of hypertension affects bone mineral density and, therefore, can worsen osteoporosis. This narrative review considers the influence of the main etiologic factors that contribute to the development of hypertension and osteoporosis and examines the effect of the most often used antihypertensives on bones. A computerized literature search of relevant English publications regarding the etiology of hypertension and osteoporosis as well as the impact of antihypertensives on osteoporosis from 1996 to 2011 was completed in October 2011. The latest update in the search was performed from May to June 2012. The most relevant nongenetic factors in the etiology of osteoporosis and hypertension are low calcium intake, vitamin D and vitamin K deficiency, high consumption of sodium salt, and the effects of different forms of nitric oxide. Thiazide diuretics are the only antihypertensives that have a positive influence on bone mineral density. For other antihypertensive drugs, the data are conflicting, indicating that they may have a potentially negative or positive influence on bone mineral density and fracture risk reduction. Some studies did not find a correlation between the use of antihypertensives and bone mineral density. Due to the frequent coexistence of hypertension and osteoporosis, when selecting long-term antihypertensive therapy the potential effects of antihypertensive drugs on development, worsening, or improvement of osteoporosis should also be considered.

High Daily Dose and Being a Substrate of Cytochrome P450 Enzymes are Two Important Predictors of Drug-induced Liver Injury

Drug-induced liver injury (DILI) is complicated and difficult to predict. It has been observed that drugs with extensive hepatic metabolism have a higher likelihood of causing DILI. Cytochrome P450 (P450) enzymes are primarily involved in hepatic metabolism. Identifying the associations of DILI with drugs that are P450 substrates, inhibitors, or inducers will be extremely helpful to clinicians during the decision-making process of caring for a patient suspected of having DILI. We collected metabolism data on P450 enzymes for 254 orally administered drugs in the Liver Toxicity Knowledge Base Benchmark Dataset with a known daily dose, and applied logistic regression to identify these associations. We revealed that drugs that are substrates of P450 enzymes have a higher likelihood of causing DILI [odds ratio (OR), 3.99; 95% confidence interval (95% CI), 2.07–7.67; P < 0.0001], which is dose-independent, and drugs that are P450 inhibitors have a higher likelihood of generating DILI only when they are administered at high daily doses (OR, 6.03; 95% CI, 1.32–27.5; P = 0.0098). However, drugs that are P450 inducers are not observed to be associated with DILI (OR, 1.55; 95% CI, 0.65–3.68; P = 0.3246). Our findings will be useful in identifying the suspected medication as a cause of liver injury in clinical settings.

Protective role of glutathione reductase in paraquat induced neurotoxicity

Paraquat (PQ), a widely used herbicide is a well-known free radical producing agent. The mechanistic pathways of PQ neurotoxicity were examined by assessing oxidative/nitrosative stress markers. Focus was on the role of glutathione (GSH) cycle and to examine whether the pre-treatment with enzyme glutathione reductase (GR) could protect the vulnerable brain regions (VBRs) against harmful oxidative effect of PQ. The study was conducted on Wistar rats, randomly divided in five groups: intact-control group, (n = 8) and four experimental groups (n = 24). All tested compounds were administered intrastriatally (i.s.) in one single dose. The following parameters of oxidative status were measured in the striatum, hippocampus and cortex, at 30 min, 24 h and 7 days post treatment: superoxide anion radical (O₂·⁻), nitrate (NO₃⁻), malondialdehyde (MDA), superoxide dismutase (SOD), total GSH (tGSH) and its oxidized, disulfide form (GSSG) and glutathione peroxidase (GPx). Results obtained from the intact and the sham operated groups were not statistically different, confirming that invasive i.s. route of administration would not influence the reliability of results. Also, similar pattern of changes were observed between ipsi- and contra- lateral side of examined VBRs, indicating rapid spatial spreading of oxidative stress. Mortality of the animals (10%), within 24h, along with symptoms of Parkinsonism, after awakening from anesthesia for 2-3 h, were observed in the PQ group, only. Increased levels of O₂·⁻, NO₃⁻ and MDA, increased ratio of GSSG/GSH and considerably high activity of GPx were measured at 30 min after the treatment. Cytotoxic effect of PQ was documented by drastic drop of all measured parameters and extremely high peak of the ratio GSSG/GSH at 24th hrs after the PQ i.s. injection. In the GR+PQ group, markedly low activity of GPx and low content of NO₃⁻ (in striatum and cortex) were measured during whole experiment, while increase value was observed only for O₂·⁻, at 7th days. We concluded that oxidative/nitrosative stress and excitotoxicity are the most important events since the early stage of PQ induced neurotoxicity. Based on the ratio GSSG/GSH, the oxidation of GSH to GSSG is probably dominant way of GHS depletion and main reason for reduced antioxidative defense against PQ harmful oxidative effect. The GR pre-treatment resulted in the absence of Parkinsons disease-like symptoms and mortality of the rats. Additionally, oxidative/nitrosative stress did not developed, as well as almost diminished metabolism of the VBRs at 24th hours (as has been documented in the PQ group) did not occurred in the GR+PQ, suggesting a neuroprotective role for the GR in PQ induced neurotoxicity.

Social-economic factors and irrational antibiotic use as reasons for antibiotic resistance of bacteria causing common childhood infections in primary healthcare

The most prevalent childhood bacterial infections in primary healthcare are respiratory, gastrointestinal and urogenital infections. The main aim of this paper was to consider factors (socio-economic factors and irrational antibiotic use) that contribute to the development of bacterial resistance, as well as measures that resulted in a reduction of this problem. Computerized search through the Medline of published articles on antibiotic resistance from 1996 to 2011 in English or Serbian was completed in August 2011. Combinations of used terms were antimicrobial/antibacterial/antibiotic and resistance/susceptibility in pediatric/children, and Streptococcus pneumoniae/Streptococci/Haemophilus influenzae/Salmonellae/Escherichia coli/Shigella/Staphylococcus aureus as well as antibiotics/antimicrobials/antibacterials and consumption/utilization/use. In many developing countries, antibiotic dispensing and its use in medicine, cattle breeding and agriculture are inadequately regulated, or existing laws are not being appropriately implemented. In addition, human travel contributes to antimicrobial drug resistance around the world. All of these factors have led to a very high level of bacterial resistance. On the contrary, in countries with a clearly defined and implemented legal framework concerning antibiotic prescribing, dispensing and utilization, the use of antibiotics is under constant surveillance. That resulted in a significantly lower antibacterial resistance. In conclusion, bacterial resistance could be reduced by the implementation of systemic and long-term measures at a country level as well as at all levels of healthcare. In order to reduce bacterial resistance, antibiotic use needs to be precisely regulated, and regulations should be coherent with practice. The international community must have a more active role in solving this global problem.

Associations of Gender and Age with the Reporting of Drug‐Induced Hepatic Failure: Data from the VigiBase™

Patient gender and age are considered to be the risk factors for developing drug‐induced liver injury (DILI). The aim of this study was to analyze gender and age differences in reporting of drug‐induced hepatic failure (HF) to the VigiBase™. VigiBase™ was screened for the HF reports submitted from 2000 to 2009. The information retrieved referred to the suspected drug, age, gender, and a reporting country. Variables were examined by using descriptive statistics and the binomial test. During the 10‐year period there were in total 6 370 HF reports from 38 countries. After the exclusion of cases with missing gender data (379 cases), females counted for 54.03%. The largest portion of HF cases referred to age <55 (42.57%) with female predominance (56.81%), whereas age ≥55 (32.57%) showed almost even gender distribution. Overall, there were 941 different drugs or their combinations reported. Females significantly predominated in HF cases associated with analgesics, antiepileptics, antiinflamatory and antirheumatic drugs, psychoanaleptics, antibacterials for systemic use, and antidiabetic drugs. Males were significantly overrepresented in HF cases associated with antivirals for systemic use. Differences between genders and/or age groups in the reporting of drug‐induced HF depend on drug and/or drug class but may be influenced by multiple factors.

Drug induced hepatotoxicity: data from the Serbian pharmacovigilance database.

The main aim of this study was to determine the most frequently reported drugs to the Serbian Pharmacovigilance Database (SPD) with suspected induced hepatotoxicity. Additionally, reasons for the low reporting rate of adverse drug reactions (ADRs) in Serbia were identified.

The Health Benefits of Vitamin D Relevant for Tuberculosis

Summary Vitamin D has an important role in numerous physiological functions. Vitamin D receptors are characterized by polymorphisms and presence in different tissues including a number of cells of the immune system. The role of vitamin D as a biological inhibitor of inflammatory hyperactivity is of particular importance. Hypovitaminosis D has been associated with many serious chronic diseases, such as autoimmune, infectious and cardiovascular diseases as well as some types of cancer. Vitamin D has an influence on the immune res ponse to tuberculosis. Calcitriol (1,25-dihydro xycholecalciferol), the major active form of vitamin D, has shown in vitro activity against Mycobacterium tuberculosis. It has been found that susceptibility to chronic mycobacterial infections is strongly correlated with a low vi tamin D intake and particular VDR alleles. Vitamin D deficiency might predispose the individuals infected with Myco bacterium tuberculosis to develop tu-ber culosis. Calcitriol binds to vitamin D receptors and modulates immune responses by regulating the transcription of genes responsive to vitamin D. Faster conversion of sputum mycobacterial culture in patients with pulmonary tuberculosis is associated with being a carrier of the t allele of the T a q I vitamin D receptor polymorphism. On the contrary, slower spu tum culture conversion in pulmonary tuberculosis has been found in the carriers of the f allele of the FokI vitamin D receptor polymorphism. The results of in vitro studies, clini-cal research and population studies indicated that vitamin D deficiency might be a strong risk factor for developing TB. Vitamin D is an inexpensive, easily accessible vitamin, relevant for the prevention of tuberculosis. In addition, vitamin D could contribute to the success of tuberculosis treatment.