Warfarin Dosing According to the Genotype-guided Algorithm is Most Beneficial in Patients With Atrial Fibrillation: A Randomized Parallel Group Trial.

BACKGROUND: Observational studies have indicated potential benefits of CYP2C9- and VKORC1-guided dosing of warfarin but randomized clinical trials have resulted in contradictory findings. One of the reasons for contradiction may be the negligence of possible differences between warfarin indications. This study aims to determine efficacy and safety of genotype-guided and clinically guided dosing of warfarin in atrial fibrillation (AF), deep-vein thrombosis (DVT), and pulmonary embolism (PE) within the first 5 days after the introduction of therapy. METHODS: In this single-center, single-blinded, randomized, controlled trial including patients of both sexes, ≥18 years of age, and diagnosed with AF, DVT, or PE, a total of 205 consecutive patients were allocated into the group where warfarin therapy was genotype-guided pharmacogenetics guided (PHG), and where it was adjusted according to the clinical parameters non pharmacogenetics guided (NPHG). Genotyping of CYP2C9*2, *3, and VKORC1 was performed using the real-time polymerase chain reaction method. The primary outcomes were the percentage of time in the therapeutic international normalized ratio (INR) (2.0-3.0) range and the percentage of patients who achieved a stable anticoagulation defined as the INR (2.0-3.0) range in at least 2 consecutive measurements. RESULTS: In patients with AF, the percentage of time spent in the therapeutic range of INR was higher in the PHG group [mean = 26% (SD 25.0)] than in the NPHG group [mean = 14% (SD 18.6)], [Δ = 12; 95% confidence interval, 0-23; P = 0.040]. There was no significant difference in other 2 indications for warfarin treatment. A stable dose of warfarin was achieved in a statistically higher number of patients in the PHG group 14/30 (47%) than in the NPHG group 7/32 (22%) (odds ratio = 3.13, 95% confidence interval, 0.92-10.98; P = 0.039). CONCLUSIONS: CYP2C9 and VKORC1 genotype-guided dosing of warfarin may be beneficial in patients diagnosed with AF. There is no evidence for such conclusion in patients with DVT and PE.

Hypersensitivity reactions to low molecular weight heparins: different patterns of cross-reactivity in 3 patients.

Low molecular weight heparins (LMWHs) are used for a variety of indications. The most common type of hypersensitivity reactions to LMWHs are delayed-type hypersensitivity reactions (DHR). Immediate-type hypersensitivity reactions (IHR) occur only sporadically. Cross-reactivity of different LMWHs is a common and unpredictable problem. We present 2 cases of patients who developed DHR to nadroparin and enoxaparin, respectively. The third case presents a patient who developed IHR to nadroparin. Skin tests confirmed the hypersensitivity in all cases. In the cases of DHR, a skin test negative LMWH was identified and was tolerated in a challenge test. In the IHR case, cross-reactivity to all tested LMWHs was established. We hypothesize that the degree of cross-reactivity might depend on the type of hypersensitivity reaction with immediate reactions linked to more extensive cross-reactivity than delayed reactions. This is important to consider because, at least in some cases, a safe alternative LMWH can be identified.

No Adverse Effects After Radioiodine Treatment at 3 Weeks of Pregnancy.

Radioactive iodine is used for the treatment of hyperthyroidism. Because it accumulates in the fetal thyroid, its administration during pregnancy may cause severe and potentially irreversible hypothyroidism in neonates, with consequent mental retardation, and it is contraindicated during the whole pregnancy. We present a case of a pregnant woman inadvertently treated with 1 mCi (37 MBq) of I in the earliest period of pregnancy and subsequently gave birth to a male infant without signs or symptoms of hypothyroidism or any other damage. This case illustrates that when radioactive iodine administration happens around the third week of gestation pregnancy outcome can be normal.

Amoxicillin-induced aseptic meningitis: case report and review of published cases
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OBJECTIVE: Amoxicillin-induced aseptic meningitis (AIAM) is an extremely rare adverse reaction with only 12 reported cases. The term aseptic meningitis refers to patients who have clinical and laboratory evidence for meningeal inflammation with negative routine bacterial cultures. Since the exact pathogenesis is still unknown and clinical signs and cerebrospinalfluid (CSF) findings vary greatly, AIAM is usually a diagnosis of exclusion. CASE SUMMARY: We report a clinical case of a patient referred to the clinical pharmacology outpatient clinic for consultation on suspected recurrent AIAM and a review of published cases. CONCLUSIONS: This report adds to the evidence-base of AIAM and emphasizes the importance of taking a thorough medication history in individuals with suspected meningitis. Considering the wide utilization of amoxicillin, it is important that healthcare providers are aware of AIAM.
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Pain relief in medical patients: does clinical judgment and prescribing knowledge suffice?

The aim of this study was to evaluate the quality of pain management in hospitalised patients. A cross-sectional study design that included all medical patients experiencing pain was used. Out of 167 patients hospitalized at the Department of Medicine at the University Hospital Zagreb, 41 patients were experiencing pain and 40 out of them received analgesics. Twenty-two out of 38 patients were treated for malignant pain, 16 for non-malignant pain, and 2 patients could not be classified. Adequate pain relief was reported in less than 25% of patients in both groups. Our study revealed under-prescribing of combination therapy, low utilization rates of strong opioids and prevailing "as needed" prescribing practice. In conclusion, unsatisfactory pain management in medical patients is often present if left solely to the clinical judgement and knowledge of the prescribing physician. Regular pain assessment, evidence-based guidelines, education and regular audits of implementation of these measures are a prerequisite for effective pain treatment, and should all be employed in patients experiencing pain.

Distributed lags time series analysis versus linear correlation analysis (Pearson's r) in identifying the relationship between antipseudomonal antibiotic consumption and the susceptibility of Pseudomonas aeruginosa isolates in a single Intensive Care Unit of a tertiary hospital.

The relationship between antibiotic consumption and selection of resistant strains has been studied mainly by employing conventional statistical methods. A time delay in effect must be anticipated and this has rarely been taken into account in previous studies. Therefore, distributed lags time series analysis and simple linear correlation were compared in their ability to evaluate this relationship. Data on monthly antibiotic consumption for ciprofloxacin, piperacillin/tazobactam, carbapenems and cefepime as well as Pseudomonas aeruginosa susceptibility were retrospectively collected for the period April 2006 to July 2007. Using distributed lags analysis, a significant temporal relationship was identified between ciprofloxacin, meropenem and cefepime consumption and the resistance rates of P. aeruginosa isolates to these antibiotics. This effect was lagged for ciprofloxacin and cefepime [1 month (R=0.827, P=0.039) and 2 months (R=0.962, P=0.001), respectively] and was simultaneous for meropenem (lag 0, R=0.876, P=0.002). Furthermore, a significant concomitant effect of meropenem consumption on the appearance of multidrug-resistant P. aeruginosa strains (resistant to three or more representatives of classes of antibiotics) was identified (lag 0, R=0.992, P<0.001). This effect was not delayed and it was therefore identified both by distributed lags analysis and the Pearson's correlation coefficient. Correlation coefficient analysis was not able to identify relationships between antibiotic consumption and bacterial resistance when the effect was delayed. These results indicate that the use of diverse statistical methods can yield significantly different results, thus leading to the introduction of possibly inappropriate infection control measures.

Clinical pharmacology consultation: a better answer to safety issues of drug therapy during pregnancy?

PURPOSE: drug safety classifications give a very basic estimation of risk and should only be used as general guideline when assessing risk of pregnancy-related drug exposure or planning treatment. We conducted a study to assess the strength of association between both the clinical pharmacologists' risk assessment and the FDA risk categorization, and adverse pregnancy outcomes. METHODS: we retrospectively reviewed records of 1,076 patients consecutively referred to the clinical pharmacology outpatient clinic for pregnancy-related drug exposure (2000-2008). Clinical pharmacologists' risk assessments were reviewed in relation to FDA drug categorization and available pregnancy outcomes. RESULTS: overall, clinical pharmacologists' risk estimation was in agreement with the FDA risk categorization system in only 28% of consulted women, and in only 9% of women with high-risk exposure (FDA DX). Clinical pharmacologists' risk assessment confirming high-risk drug exposure had a better positive predictive value for adverse pregnancy outcomes than the FDA DX categorization (25% vs 14% respectively), while the negative predictive values were similar (92% vs 94% respectively). Clinical pharmacologists' risk assessment was a better predictor of adverse pregnancy outcomes compared with FDA risk categorization (OR 2.11 [95%CI 1.5-3.1; p < 0.001] vs OR 1.52 [95%CI 1.1-2.1; p = 0.014] respectively). CONCLUSIONS: additional evaluation beyond the FDA drug classification is essential for safer and more rational drug use in pregnancy. Clinical pharmacologists who have undergone rigorous medical training are ideally placed to consult on administration of medicines in pregnant women, thus making the prescribing of treatments in that patient category substantially safer and more rational.

Is referring patients with a positive history of allergic drug reactions or atopy for allergy testing to local anesthetics justified?

Although no more than 1% of adverse reactions to local anesthetics (LA) are thought to be immunologically mediated, many patients continue to be referred to allergy clinics for allergy workup. We evaluated the impact of a history of drug hypersensitivity or atopy on results of allergy testing to LA, with the aim of determining the appropriateness of allergy testing to LA in such patients. We retrospectively analyzed medical records of 112 consecutive patients referred for allergy testing to LA in a 9-year period (1996-2005). Intradermal tests with diluted (1:10) LA were performed to identify patients at risk for immunoglobulin E (IgE)-mediated hypersensitivity reaction. The odds for being testpositive were calculated with regard to the defined risk factors (atopy, history of adverse reactions to LA or other drugs, underlying autoimmune disease). Eleven of 112 patients (9.8%) tested positive for allergy to LA. Atopy, history of adverse reactions to LA or other drugs and underlying autoimmune disease did not increase the odds for being test-positive. The prevalence of multiple drug hypersensitivity, IgE values and eosinophil count were not significantly higher among the patients who tested positive as compared to the patients who tested negative. According to our data, allergy testing to LA is not justified in patients with atopy or histories of adverse drug reactions other than to LA. Further studies using validated methods of allergy testing to LA coupled with analysis of defined risk factors are needed to definitively establish the indications for referral of patients for allergy testing to LA.

Impact of aminoglycoside cycling in six tertiary intensive care units: prospective longitudinal interventional study.

AIM: To determine the effect of aminoglycoside cycling in six tertiary intensive care units (ICU) on the rates of sepsis, aminoglycoside resistance patterns, antibiotic consumption, and costs. METHODS: This was a prospective longitudinal interventional study that measured the effect of change from first-line gentamicin usage (February 2002-February 2003) to amikacin usage (February 2003-February 2004) on the aminoglycoside resistance patterns, number of patients with gram-negative bacteremia, consumption of antibiotics, and the cost of antimicrobial drugs in 6 tertiary care ICUs in Zagreb, Croatia. RESULTS: The change from first-line gentamicin to amikacin usage led to a decrease in the overall gentamicin resistance of gram-negative bacteria (GNB) from 42% to 26% (P<0.001; z-test of proportions) and netilmicin resistance from 33% to 20% (P<0.001), but amikacin resistance did not change significantly (P=0.462), except for Acinetobacter baumanni (P=0.014). Sepsis rate in ICUs was reduced from 3.6% to 2.2% (P<0.001; chi(2) test), with a decline in the number of nosocomial bloodstream infections from 55/100 patient-days to 26/100 patient-days (P=0.001, chi(2) test). Furthermore, amikacin use led to a 16% decrease in the overall antibiotic consumption and 0.1 euro/patient/d cost reduction. CONCLUSION: Exclusive use of amikacin significantly reduced the resistance of GNB isolates to gentamicin and netilmicin, the number of GNB nosocomial bacteremias, and the cost of total antibiotic usage in ICUs.

Antibiotic use optimization program in the largest Croatian university hospital--benefits of restrictions on unlimited antibiotic use.

The aim of this study was to obtain the relevant information on antibiotic use in a 750-bed Croatian university hospital. The study has been designed as a 2-point prevalence interventional analysis. For each patient on antibiotic therapy, diagnosis, indication for treatment, antibiotic therapy, dosage and route of administration together with the results of microbiological studies (if available) were obtained. After the first prevalence analysis in 2001, a restriction on unlimited antibiotic use was introduced. The second analysis, performed in 2002, after restrictions on antibiotic use, revealed reductions in the rates of restricted release antibiotics and overall antibiotic use with decreases from 38.6% to 36.9% and 23.4% to 23.2% respectively (p = 0.87). The first survey showed that the 5 most often prescribed antibiotics in the therapy of bacterial infections were: gentamicin, other aminoglycosides, carbapenems, amoxycillin +clavulanate and vancomycin with proportions of 14.8%, 10.3%, 8.2%, 7% and 7% respectively. In the year 2002, the most prescribed antimicrobial drugs in the therapy of bacterial infections were: gentamicin, quinolones, vancomycin, carbapenems and cefuroxime with proportions of 18.6%, 11.4%, 9.7%, 9.3% and 8% respectively. A reduction in the proportions of doubtful antibiotic therapy, from 24.6% before the intervention, to 24.2% after the restrictions, accompanied by a 0.4% rise in the rates of indicated antibiotic therapy was also observed (p = 0.93). Our study shows that restrictions on formerly unlimited use of antimicrobials, even when leading to an improvement in their prescribing, do not necessarily cause rapid and significant reduction in the overall use of antibiotics or explicit positive financial effects.

Use of gastroprotective agents in recommended doses in hospitalized patients receiving NSAIDs: a drug utilization study.

OBJECTIVE: In recent years, studies investigated to what extend recommendations for co-prescribing gastroprotective agents in prevention of NSAID-induced gastrointestinal complications are followed in clinical practice. However, only a few studies have also taken into consideration the recommended dose of gastroprotectives prescribed in NSAID-induced ulcer prophylaxis. The aim of our study was to evaluate the prevalence of concomitant use of gastroprotectives with NSAIDs in hospitalized patients, with emphasis on the recommended dose of gastroprotectives for ulcer prophylaxis. METHOD: This observational, cross-sectional, drug utilization study included all adult patients receiving NSAIDs hospitalized in the Clinical Hospital Center Zagreb on the day of the study. Data on age, sex, comorbidities, indications for NSAID use, type/dose of NSAIDs and gastroprotectives, history of gastrointestinal events, active gastrointestinal symptoms and risk factors were evaluated. MAIN OUTCOME MEASURE: Study outcomes were: (1) prevalence of prescription of gastroprotectives among NSAID-users at risk; (2) prevalence of prescription of gastroprotective in recommended dose; (3) association between risk factors and prescription of GPAs. RESULTS: The rates of gastroprotectives prescription were significantly higher in NSAID-users with concomitant risk factors as compared to patients without risk factors [47/70 (67.1%) and 8/22 (36.4%), respectively; p=0.01072]. However, gastroprotection in recommended ulcer-preventive dose was low in both groups [8/70 (11.4%) and 9/92 (9.8%), respectively]. The number of concomitant risk factors did not increase the odds of receiving anti-ulcer therapy (odds ratio 0.7279). Thirty-three percent of patients with concomitant risk factors were not prescribed gastroprotectives. Ibuprofen, NSAID with the lowest risk of inducing gastrointestinal complications, was prescribed in only two patients. CONCLUSION: The results indicate high awareness among hospital physicians about possible NSAID-induced gastrointestinal complications, but insufficient knowledge about risk factors related to NSAID-induced gastrointestinal toxicity, recommended dose of gastroprotectives in NSAID-induced ulcer prophylaxis and gastrointestinal toxicity of different types of NSAIDs.

[Evaluation of justification for antibiotic use at the Internal Medicine Clinic of the Clinical Hospital in Zagreb]. / Procjena opravdanosti potrosnje antibiotika u Klinici za unutrasnje bolesti Klinickog bolnickog centra Zagreb.

OBJECTIVE: Resistance to antimicrobials as the result of unnecessary and inadequate use of antibiotics has become a global health problem. It is estimated that up to 50% of antimicrobials are used unnecessarily, and that they are the cause of approximately 25% of adverse drug reactions. Efforts are made to ensure a controlled use of antibiotics, which is the key strategy against development of resistance to antimicrobials. Since antimicrobial drugs are among the most commonly prescribed drugs in hospitals, a rational use of antibiotics would also help reduce health care costs. There are limited data on the use of antibiotics in Croatian hospitals. METHODS: This observational study was conducted at the University Department of Medicine, Zagreb University Hospital Center, with the aim to investigate the prevalence of antimicrobial use, indications for antibiotic use, and the necessity and adequacy of antibiotic therapy. The investigated parameters were: prescribed antibiotic (dose, route of administration, duration of therapy), indication for use of antibiotics (prophylaxis, treatment), diagnosis, presence of positive culture, indication documented in medical records, evaluation of antibiotic therapy by a specialist, and risk factors. The most important parameter in the evaluation of the necessity of antimicrobial use was the presence of culture days of treatment, and indication for treatment documented in medical records and evaluated by a specialist. The data were collected over 1 day using a standardized questionnaire. RESULTS: Fifty of 138 (37%) hospitalized patients were receiving 1 or more antibiotics, most of them (80%) for the treatment of infection. The most frequent diagnoses were sepsis (64%), urinary tract infection (25%), abdominal infection (21%), and pulmonary infection (7%). The median therapy duration was 4 days (minimum 1 day, maximum 121 days). The most frequently prescribed antibiotics were fluoroquinolones (23%), penicillins (23%), aminoglycosides (18%) and cephalosporins (11%). Thirty-nine patients received one or more reserve antibiotics. The median number of received antibiotics was 2 (minimum 1, maximum 5 antibiotics). Risk factors were present in 76% of patients. Fifty-nine percent patients were receiving antibiotics on the basis of culture; in most of them therapy was evaluated by a specialist (98%) and the indication was documented in medical records. Reserve antibiotics were prescribed in 34 patients, in 77% of them on the basis of positive culture. CONCLUSION: The high prescription rate of antibiotics (fluoroquinolones), concomitant use of antibiotics of a similar spectrum of activity and lack of sequential therapy emerged to be the parameters needing further evaluation. Other investigated parameters (number of antibiotics, duration of therapy, necessity of antibiotic therapy) were in accordance with similar studies conducted in hospitals. Further investigation with emphasis on local problems and prescription habits with the aim to optimize the use of antibiotics is needed.