[Risk minimalisation measures for medications; are they incorporated in Dutch clinical guidelines?] / Risicominimalisatiemaatregelen voor geneesmiddelen.

OBJECTIVE: Risk minimisation measures (RMM) are put in place to ensure safe and effective use of medicines. This study assessed whether RMM for five medicines are implemented in Dutch clinical guidelines. DESIGN: Descriptive study. METHOD: Dutch clinical guidelines where treatment with valproate, fluoroquinolones, methotrexate, metformin or fluorouracil was recommended were identified. In those guidelines that had been updated after publication of the RMM, we determined whether RMM-information was included in the guideline. RESULTS: Out of 50 identified guidelines recommending treatment with one of the five medicines, only 21 (42%) were revised after RMM-implementation. Of these 21 guidelines, 12 (n = 57%) included RMM-related information. CONCLUSION: Uptake of RMM information in Dutch clinical guidelines is limited and RMM-publication does not prompt guideline updates. This suggests that guidelines alone are not an optimal way to inform health care professionals of new safety warnings.

Oral fluoroquinolones and risk of aortic aneurysm or dissection: A nationwide population-based propensity score-matched cohort study.

STUDY OBJECTIVE: To investigate risk of aortic aneurysm or dissection in patients using oral fluoroquinolones compared to those using macrolides in real-world clinical practice among a large US general population. DESIGN: Retrospective cohort study design. DATA SOURCE: MarketScan commercial and Medicare supplemental databases. PATIENTS: Adults patients with at least one prescription fill for fluoroquinolone or macrolide antibiotics. INTERVENTION: Fluoroquinolone or macrolide antibiotics. MEASUREMENTS AND MAIN RESULTS: The primary outcome was estimated incidence of aortic aneurysm or dissection associated with the use of fluoroquinolones compared with macrolides during a 60-day follow-up period in a 1:1 propensity score-matched cohort. We identified 3,174,620 patients (1,587,310 in each group) after 1:1 propensity score matching. Crude incidence of aortic aneurysm or dissection was 1.9 cases per 1000 person-years among fluoroquinolone users and 1.2 cases per 1000 person-years among macrolide users. In multivariable Cox regression, compared with macrolides, the use of fluoroquinolones was associated with an increased risk of aortic aneurysm or dissection (aHR: 1.34; 95% CI: 1.17-1.54). The association was primarily driven by a high incidence of aortic aneurysm cases (95.8%). Results of sensitivity (e.g., fluoroquinolone exposure ranging from 7 to 14 days (aHR: 1.47; 95% CI: 1.26-1.71)) and subgroup analyses (e.g., ciprofloxacin (aHR: 1.26; 95% CI: 1.07-1.49) and levofloxacin (aHR: 1.44; 95% CI: 1.19-1.52)) remained consistent with main findings. CONCLUSIONS: Fluoroquinolone use was associated with a 34% increased risk of aortic aneurysm or dissection compared with macrolide use among a general US population.

Healthcare costs and mortality associated with serious fluoroquinolone-related adverse reactions.

The aim of this study was to estimate healthcare costs and mortality associated with serious fluoroquinolone-related adverse reactions in Finland from 2008 to 2019. Serious adverse reaction types were identified from the Finnish Pharmaceutical Insurance Pool's pharmaceutical injury claims and the Finnish Medicines Agency's Adverse Reaction Register. A decision tree model was built to predict costs and mortality associated with serious adverse drug reactions (ADR). Severe clostridioides difficile infections, severe cutaneous adverse reactions, tendon ruptures, aortic ruptures, and liver injuries were included as serious adverse drug reactions in the model. Direct healthcare costs of a serious ADR were based on the number of reimbursed fluoroquinolone prescriptions from the Social Insurance Institution of Finland's database. Sensitivity analyses were conducted to address parameter uncertainty. A total of 1 831 537 fluoroquinolone prescriptions were filled between 2008 and 2019 in Finland, with prescription numbers declining 40% in recent years. Serious ADRs associated with fluoroquinolones lead to estimated direct healthcare costs of 501 938 402 €, including 11 405 ADRs and 3,884 deaths between 2008 and 2019. The average mortality risk associated with the use of fluoroquinolones was 0.21%. Severe clostridioides difficile infections were the most frequent, fatal, and costly serious ADRs associated with the use of fluoroquinolones. Although fluoroquinolones continue to be generally well-tolerated antimicrobials, serious adverse reactions cause long-term impairment to patients and high healthcare costs. Therefore, the risks and benefits should be weighed carefully in antibiotic prescription policies, as well as with individual patients.

Health service use and costs associated with fluoroquinolone-related tendon injuries.

The aim of this study was to assess costs and health service use associated with tendon injuries after the use of fluoroquinolone antimicrobials in Finland during 2002-2012. This retrospective observational study included data from the Finnish Pharmaceutical Insurance Pool's pharmaceutical injury claims. In total, 145 compensated claimants aged ≥18 years presenting tendon injuries after the use of fluoroquinolones (FQs) were included in the study. Outcomes of interest were the number of outpatient visits to primary, secondary, tertiary, and private healthcare services, hospital days, rehabilitation and their costs. Regression models were used to analyze the impact of patient characteristics on hospital days, as well as the relationship between patient characteristics and tendon ruptures. Direct costs of a tendon injury averaged 14,800€ and indirect costs were estimated to be 9,077€ for employed claimants. Fifty-one percent of the claimants were hospitalized, with an average duration of 21 days. Hospitalization was the costliest form of health service use with an average of 9,915€ per hospital episode. Hospital days and direct costs increased with the severity of the injury. Tendon ruptures, in particular bilateral ruptures, required substantially more hospital days and their direct costs were significantly higher than those of uncomplicated tendinitis. Concurrent use of oral corticosteroids and increasing age were associated with a higher likelihood of tendon ruptures. Although rare, FQ-related tendon injuries can result in considerable costs and health service use. Medical staff should remain vigilant when prescribing FQs, especially in groups at increased risk for tendon injuries.

Testes comerciais de sondas em linha para detecção do complexo Mycobacterium tuberculosis (MTB), de mutações nas regiões determinantes de resistência a rifampicina e isoniazida (1ª linha) e a fluoroquinolonas e aminoglicosídeos (2ª linha) / Commercial on-line probe tests for detection of Mycobacterium tuberculosis complex (MTB), mutations in rifampicin and isoniazid-resistance-determining regions (1st line) and fluoroquinolones and aminoglycosides (2nd line)

INTRODUÇÃO: Os testes de sonda em linha (LPA) são ensaios qualitativos que utilizam membranas de nitrocelulose com sondas de regiões parciais de genes de resistência. O GenoType MTBDRplus® , a partir de amostras de escarro positivo ou de culturas positivas, identifica o complexo M. tuberculosis e as principais mutações que conferem resistência à rifampicina e isoniazida a partir de sondas das regiões parciais de resistência de determinados genes. O GenoType MTBDRsl® possibilita a identificação de resistência também aos medicamentos injetáveis e de segunda linha, por meio de sondas de genes de resistência conhecidos. A população alvo desse abarca indivíduos com comorbidades ou não, de ambos os sexos, todas as idades, provenientes de qualquer país independentemente da incidência e prevalência regionais da doença, com suspeita de tuberculose pulmonar ou extrapulmonar ou indivíduos diagnosticados com tuberculose, independentemente da baciloscopia, tratados previamente ou não, e suspeita de resistência a drogas de primeira ou segunda linha utilizadas no tratamento das formas resistentes da doença. EQUIPAMENTO: Testes comerciais de sondas em linha para detecção do complexo Mycobacterium tuberculosis (MTB), de mutações nas regiões determinan

Comparative Effectiveness and Harms of Antibiotics for Outpatient Diverticulitis : Two Nationwide Cohort Studies.

BACKGROUND: Outpatient diverticulitis is commonly treated with either a combination of metronidazole and a fluoroquinolone (metronidazole-with-fluoroquinolone) or amoxicillin-clavulanate alone. The U.S. Food and Drug Administration advised that fluoroquinolones be reserved for conditions with no alternative treatment options. The comparative effectiveness of metronidazole-with-fluoroquinolone versus amoxicillin-clavulanate for diverticulitis is uncertain. OBJECTIVE: To determine the effectiveness and harms of metronidazole-with-fluoroquinolone versus amoxicillin-clavulanate for outpatient diverticulitis. DESIGN: Active-comparator, new-user, retrospective cohort studies. SETTING: Nationwide population-based claims data on U.S. residents aged 18 to 64 years with private employer-sponsored insurance (2000 to 2018) or those aged 65 years or older with Medicare (2006 to 2015). PARTICIPANTS: Immunocompetent adults with diverticulitis in the outpatient setting. INTERVENTION: Metronidazole-with-fluoroquinolone or amoxicillin-clavulanate. MEASUREMENTS: 1-year risks for inpatient admission, urgent surgery, and Clostridioides difficile infection (CDI) and 3-year risk for elective surgery. RESULTS: In MarketScan (IBM Watson Health), new users of metronidazole-with-fluoroquinolone (n = 106 361) and amoxicillin-clavulanate (n = 13 160) were identified. There were no differences in 1-year admission risk (risk difference, 0.1 percentage points [95% CI, -0.3 to 0.6]), 1-year urgent surgery risk (risk difference, 0.0 percentage points [CI, -0.1 to 0.1]), 3-year elective surgery risk (risk difference, 0.2 percentage points [CI, -0.3 to 0.7]), or 1-year CDI risk (risk difference, 0.0 percentage points [CI, -0.1 to 0.1]) between groups. In Medicare, new users of metronidazole-with-fluoroquinolone (n = 17 639) and amoxicillin-clavulanate (n = 2709) were identified. There were no differences in 1-year admission risk (risk difference, 0.1 percentage points [CI, -0.7 to 0.9]), 1-year urgent surgery risk (risk difference, -0.2 percentage points [CI, -0.6 to 0.1]), or 3-year elective surgery risk (risk difference, -0.3 percentage points [CI, -1.1 to 0.4]) between groups. The 1-year CDI risk was higher for metronidazole-with-fluoroquinolone than for amoxicillin-clavulanate (risk difference, 0.6 percentage points [CI, 0.2 to 1.0]). LIMITATION: Residual confounding is possible, and not all harms associated with these antibiotics, most notably drug-induced liver injury, could be assessed. CONCLUSION: Treating diverticulitis in the outpatient setting with amoxicillin-clavulanate may reduce the risk for fluoroquinolone-related harms without adversely affecting diverticulitis-specific outcomes. PRIMARY FUNDING SOURCE: National Institutes of Health.

Association between tendon ruptures and use of fluoroquinolone, and other oral antibiotics: a 10-year retrospective study of 1 million US senior Medicare beneficiaries.

OBJECTIVES: To assess the association of fluoroquinolone use with tendon ruptures compared with no fluoroquinolone and that of the four most commonly prescribed non-fluoroquinolone antibiotics in the USA. DESIGN: Retrospective observational study. SETTING: US seniors enrolled in the federal old-age, survivor's insurance programme. PARTICIPANTS: 1 009 925 Medicare fee-for-service beneficiaries and their inpatient, outpatient, prescription drug records were used. INTERVENTIONS: Seven oral antibiotics, fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin) and amoxicillin, amoxicillin-clavulanate, azithromycin and cephalexin. PRIMARY AND SECONDARY OUTCOME MEASURES: All tendon ruptures combined, and three types of tendon ruptures by anatomic site, Achilles tendon rupture, rupture of rotator cuff and other tendon ruptures occurred in 2007-2016. RESULTS: Of three fluoroquinolones, only levofloxacin exhibited a significant increased risk of tendon ruptures-16% (HR=1.16; 95% CI 1.06 to 1.28), and 120% (HR=2.20; 95% CI 1.50 to 3.24) for rotator cuff and Achilles tendon rupture, respectively, in the ≤30 days window. Ciprofloxacin (HR=0.96; 95% CI 0.89 to 1.03) and moxifloxacin (HR=0.59; 95% CI 0.37 to 0.93) exhibited no increased risk of tendon ruptures combined.Among the non-fluoroquinolone antibiotics, cephalexin exhibited increased risk of combined tendon ruptures (HR=1.31; 95% CI 1.22 to 1.41) and modest to large risks across all anatomic rupture sites (HRs 1.19-1.93) at ≤30 days window. Notably, the risk of levofloxacin never exceeded the risk of the non-fluoroquinolone, cephalexin in any comparison. CONCLUSIONS: In our study, fluoroquinolones as a class were not associated with the increased risk of tendon ruptures. Neither ciprofloxacin nor moxifloxacin exhibited any risk for tendon ruptures. Levofloxacin did exhibit significant increased risk. Cephalexin with no reported effect on metalloprotease activity had an equal or greater risk than levofloxacin; so we question whether metalloprotease activity has any relevance to observed associations with tendon rupture. Confounding by indication bias may be more relevant and should be given more consideration as explanation for significant associations in observational studies of tendon rupture.

Assessment of the risk of musculoskeletal adverse events associated with fluoroquinolone use in children: A meta-analysis.

BACKGROUND: The use of fluoroquinolone antibiotics has been restricted in children because of their potential to cause adverse musculoskeletal events. This study was performed to systematically evaluate whether there is a difference between fluoroquinolone and non-fluoroquinolone antibiotics in terms of their associated risk of adverse musculoskeletal events in children. METHODS: Cochrane Library, Embase, and PubMed databases were used to retrieve studies related to fluoroquinolone and non-fluoroquinolone-induced musculoskeletal adverse events in children. A meta-analysis was performed using Stata 11. RESULTS: A total of 10 studies were included in the analysis. The combined results showed that there was no statistical difference between fluoroquinolone and non-fluoroquinolone groups in terms of musculoskeletal adverse events in children (risk ratio = 1.145, 95% confidence interval = 0.974 - 1.345, P = .101). Subgroup analysis was performed using a random-effects model. Here, the effects on the trovafloxacin and levofloxacin groups were significantly different from that of the control group. However, musculoskeletal adverse events due to either drug was not reported after long-term follow-up. CONCLUSIONS: The results showed that fluoroquinolone and non-fluoroquinolone antibiotics were not different in terms of their ability to cause musculoskeletal adverse events in children. For this reason, fluoroquinolone antibiotics can be used in children as appropriate. PROSPERO REGISTRATION NUMBER: CRD42019133900.

Pharmacist-led Penicillin Allergy Assessment in the Emergency Department Reduced Empiric Fluoroquinolone Use.

In a retrospective, quasi-experimental study of 380 adult patients with a reported penicillin allergy who received antibiotics at a community hospital emergency department, a pharmacist-led penicillin allergy assessment via medical records review and patient interview improved guideline-preferred antibiotic use by 13% (P = .018) and reduced fluoroquinolone use by 11% (P = .035).

Healthcare associated Clostridioides difficile infection in adult surgical and medical patients hospitalized in tertiary hospital in Belgrade, Serbia: a seven years prospective cohort study.

Introduction: Clostridioides difficile (C. difficile) infection (CDI) is one of the most common healthcare-associated (HA) infections in contemporary medicine. The risk factors (RFs) for HA CDI in medical and surgical patients are poorly investigated in countries with a limited resource healthcare system. Therefore, the aim of the study was to investigate differences in patients' characteristics, factors related to healthcare and outcomes associated with HA CDI in surgical and medical patients in tertiary healthcare centre in Serbia.Materials and Methods: A prospective cohort study was conducted including adult patients diagnosed with initial episode of HA CDI, first recurrence of disease, readmission to hospital, while deaths within 30 days of CDI diagnosis and in-hospital mortality were also recorded. Patients hospitalized for any non-surgical illness, who developed initial HA CDI were assigned to medical group, whereas those who developed initial HA CDI after surgical procedures were in surgical group. The data on patients' characteristics and factors related to healthcare were collected, too.Results: During 7-year period, from 553 patients undergoing in-hospital treatment and diagnosed with CDI, 268 (48.5%) and 285 (51.5%) were surgical and medical patients, respectively. Age ≥ 65 years, use of proton pump inhibitors, chemotherapy and fluoroquinolones were positively associated with being in medical group, whereas admission to intensive care unit and use of second- and third-generation cephalosporins were positively associated with being in surgical group.Conclusions: Based on obtained results, including significant differences in 30-day mortality and in-hospital mortality, it can be concluded that medical patient were more endangered with HA CDI than surgical ones.

Fluoroquinolone-related adverse events resulting in health service use and costs: A systematic review.

BACKGROUND AND OBJECTIVES: Adverse events (AEs) associated with the use of fluoroquinolone antimicrobials include Clostridium difficile associated diarrhea (CDAD), liver injury and seizures. Yet, the economic impact of these AEs is seldom acknowledged. The aim of this review was to identify health service use and subsequent costs associated with ciprofloxacin, levofloxacin, moxifloxacin, norfloxacin and ofloxacin -related AEs. METHODS: A literature search covering Medline, SCOPUS, Cinahl, Web of Science and Cochrane Library was performed in April 2017. Two independent reviewers systematically extracted the data and assessed the quality of the included studies. All costs were converted to 2016 euro in order to improve comparability. RESULTS: Of the 5,687 references found in the literature search, 19 observational studies, of which five were case-controlled, fulfilled the inclusion criteria. Hospitalization was an AE-related health service use outcome in 17 studies. Length of hospital stay associated with AEs varied between <5 and 45 days. The estimated cost of an AE episode ranged between 140 and 18,252 €. CDAD was associated with the longest stays in hospital. Ten studies reported AE-related length of stays and five evaluated costs associated with AEs. Due to the lack of published literature, health service use and costs associated with many high-risk FQ-related AEs could not be evaluated. CONCLUSIONS: Because of the wide clinical use of fluoroquinolones, in particular serious fluoroquinolone-related AEs can have substantial economic implications, in addition to imposing potentially devastating health complications for patients. Further measures are required to prevent and reduce health service use and costs associated with fluoroquinolone-related AEs. Equally, better-quality reporting and additional published data on health service use and costs associated with AEs are needed.

Adverse reactions of fluoroquinolones to central nervous system and rational drug use in nursing care.

.Fluoroquinolones are a kind of synthetic drugs commonly used in clinical treatment. They have good broad-spectrum antimicrobial properties. They are not only convenient to administer, but also have remarkable therapeutic effects. In this paper, we selected 70 patients with adverse reactions of central nervous system during the use of fluoroquinolones as the research object. We reviewed and analyzed the basic data, main manifestations and outcomes of adverse reactions, and summarized the influencing factors. The results showed that dizziness, irritability and insomnia were the main symptoms in 42 patients with mild adverse reactions. In 28 patients with moderate to severe adverse reactions, neuropsychiatric symptoms such as restlessness, depression, nervous excitation, phonism and hallucination were found. 54 patients were able to recover after stopping the medication. The remaining 16 patients were treated with drugs, and the effective rate was 87.5%. By analyzing the related factors, it can be seen that elderly patients over 60 years old, intravenous administration, combination of drugs and past history of neurological diseases are the main factors leading to adverse reactions of the central nervous system. In this survey, there were 7 kinds of adverse drug reactions, of which 31 cases (44.28%) were caused by levofloxacin. Therefore, fluoroquinolones have adverse effects on the central nervous system in the course of treatment, and the occurrence of adverse reactions is related to patients' age, route of administration, drug combination and past history of illness. It is important to grasp the above factors and make rational use of drugs.

Effectiveness and safety of the pre-prescription of garenoxacin in comparison to moxifloxacin for low-risk febrile neutropenia in breast cancer patients undergoing adjuvant and neoadjuvant chemotherapy.

PURPOSE: The purpose of this study was to compare the efficacy of the pre-prescription of garenoxacin mesylate hydrate (GRNX) with that of moxifloxacin hydrochloride (MFLX) in the management of breast cancer patients with low-risk febrile neutropenia. METHODS: Data from female patients who had been instructed to take previously prescribed oral GRNX or MFLX for 3 days during adjuvant and neoadjuvant chemotherapy if their body temperature exceeded 38 °C were analyzed. This study compared the effectiveness between these fluoroquinolones using a propensity score matching analysis. RESULTS: The 330 patients received 1192 administrations of chemotherapy between May 2007 and April 2014 and 136 (41.2%) patients had a total of 212 (17.8%) febrile episodes. The frequencies of febrile episodes were 19.5% (113/579) and 16.2% (99/613) in the GRNX and MFLX groups, respectively. After propensity score matching, 384 episodes were matched in each group. Febrile events occurred in 80 and 56 cases in the GRNX and MFLX groups, respectively. Treatment success was identified in 80.0% (64/80) of cases in the GRNX group and 64.3% (36/56) of cases in the MFLX group (P = 0.0494). Additionally, the therapeutic use of granulocyte-colony stimulating factor was 6.3% (5/80) of cases in the GRNX group and 17.9% (10/56) of cases in the MFLX group (P = 0.0498). There were few differences in the frequency of adverse effects between the two groups. CONCLUSIONS: These results indicate that the pre-prescription of GRNX may be a more effective option for the management of low-risk febrile neutropenia during adjuvant and neoadjuvant chemotherapy for breast cancer.

Analyzing intent-to-treat and per-protocol effects on safety outcomes using a medical information database: an application to the risk assessment of antibiotic-induced liver injury.

OBJECTIVE: To apply a causal analysis approach to estimate the intent-to-treat and per-protocol effects in a safety outcome study of the 30-day risk of liver injury associated with antibiotic use (macrolides, penicillin-based antibiotics, and fluoroquinolones). RESEARCH DESIGN AND METHODS: For each antibiotic class, we constructed a pooled cohort of treated episodes matched with untreated episodes using an electronic medical record database from a university hospital. High-dimensional propensity scores were calculated using baseline patient characteristics, concomitant medications and medical history as surrogate confounders. Intent-to-treat hazard ratios (HRs) were estimated using inverse probability of treatment weighted discrete hazard models that ignored subsequent treatment changes. Per-protocol HRs were calculated using inverse probability of treatment and censoring weighted models after terminating each episode's observation at the first treatment change. RESULTS: For macrolides, the intent-to-treat HR (95% confidence interval) was 1.22 (0.75-1.98) and the per-protocol HR was 1.22 (0.67-2.22). For penicillin-based antibiotics, the intent-to-treat HR was 4.01 (3.16-5.08) and the per-protocol HR was 7.25 (5.58-9.41). For fluoroquinolones, the intent-to-treat HR was 1.60 (1.27-2.03) and the per-protocol HR was 1.69 (1.23-2.30). CONCLUSION: Researchers should clearly define the target estimands, and carefully estimate and interpret both effects.

Estimated Cardiac Risk Associated With Macrolides and Fluoroquinolones Decreases Substantially When Adjusting for Patient Characteristics and Comorbidities.

BACKGROUND: Some studies have found that antimicrobials, especially macrolides, increase the risk of cardiovascular death. We investigated potential cardiac-related events associated with antimicrobial use in a population of patients with acute myocardial infarction. METHODS AND RESULTS: For 185 010 Medicare beneficiaries, we recorded prescriptions for azithromycin, clarithromycin, levofloxacin, moxifloxacin, doxycycline, and amoxicillin-clavulanate. In the following week, we recorded death, acute myocardial infarction, atrial fibrillation or atrial flutter, a non-atrial fibrillation/atrial flutter arrhythmia, or ventricular arrhythmia. We fit unadjusted and adjusted logistic regression models using generalized estimating equations. Adjusted models included patients' comorbidities, medications, procedures, demographics, insurance status, time since index acute myocardial infarction, number of visits, and the influenza rate. In unadjusted analyses, macrolides and fluoroquinolones were associated with a risk of cardiac events. However, the risk associated with macrolide use was substantially attenuated after adjustment for a wide range of variables, and the risk associated with fluoroquinolones was no longer statistically significant. For example, for azithromycin, the odds ratio for any cardiac event or death was 1.35 (95% confidence interval, 1.27-1.44; P<0.0001), but after controlling for a wide range of covariates, the odds ratio decreased to 1.01 (95% confidence interval, 0.95-1.08; P<0.6688). CONCLUSIONS: Controlling for covariates explains much of the adverse cardiac risk associated with antimicrobial use found in other studies. Most antimicrobials are not associated with risk of cardiac events, and others, specifically azithromycin and clarithromycin, may pose a small risk of certain cardiac events. However, the modest potential risks attributable to these antimicrobials must be weighed against the drugs' considerable and immediate benefits.

Assessment of phototoxicity in pigmented Long-Evans rat: sparfloxacin and 8-methoxypsoralen.

The aim of the present work was to evaluate the effects of photo-activated toxicity induced after administration of two known melanin-binding phototoxic compounds, sparfloxacin (SPX) and 8-methoxypsoralen (8-MOP), followed or not by UVA/Vis exposure, in pigmented rats (Long Evans: LE) and albino rats (Sprague Dawley: SD). Groups of three rats were treated with SPX or 8-MOP by oral gavage for six consecutive days. Irradiated animals were submitted to a UVA/Vis light dose standardized to 10 J/cm2 UVA daily. Clinical signs, cutaneous reactions and body weight were monitored throughout the study period. Ear biopsy weight, lymph node weight and lymph node cell count were determined at necropsy. Ophthalmologic examinations were performed before the first treatment and on the day of sacrifice. Microscopic examinations were performed on skin biopsies and eyes. Phototoxicity was demonstrated for both SPX and 8-MOP in the pigmented and albino strains, in terms of auricular irritation, lymph node weight and proliferation index, cutaneous reactions and ocular histopathology. LE rats were less sensitive than SD rats, especially at the ocular level, supporting the notion that pigmentation may provide protection against photo-activation. The pigmented rat may be a more relevant model than the albino rat for human safety evaluation.

Evaluating the Effectiveness of an Antimicrobial Stewardship Program on Reducing the Incidence Rate of Healthcare-Associated Clostridium difficile Infection: A Non-Randomized, Stepped Wedge, Single-Site, Observational Study.

BACKGROUND: The incidence rate of healthcare-associated Clostridium difficile infection (HA-CDI) is estimated at 1 in 100 patients. Antibiotic exposure is the most consistently reported risk factor for HA-CDI. Strategies to reduce the risk of HA-CDI have focused on reducing antibiotic utilization. Prospective audit and feedback is a commonly used antimicrobial stewardship intervention (ASi). The impact of this ASi on risk of HA-CDI is equivocal. This study examines the effectiveness of a prospective audit and feedback ASi on reducing the risk of HA-CDI. METHODS: Single-site, 339 bed community-hospital in Barrie, Ontario, Canada. Primary outcome is HA-CDI incidence rate. Daily prospective and audit ASi is the exposure variable. ASi implemented across 6 wards in a non-randomized, stepped wedge design. Criteria for ASi; any intravenous antibiotic use for ≥ 48 hrs, any oral fluoroquinolone or oral second generation cephalosporin use for ≥ 48 hrs, or any antimicrobial use for ≥ 5 days. HA-CDI cases and model covariates were aggregated by ward, year and month starting September 2008 and ending February 2016. Multi-level mixed effect negative binomial regression analysis was used to model the primary outcome, with intercept and slope coefficients for ward-level random effects estimated. Other covariates tested for inclusion in the final model were derived from previously published risk factors. Deviance residuals were used to assess the model's goodness-of-fit. FINDINGS: The dataset included 486 observation periods, of which 350 were control periods and 136 were intervention periods. After accounting for all other model covariates, the estimated overall ASi incidence rate ratio (IRR) was 0.48 (95% 0.30, 0.79). The ASi effect was independent of antimicrobial utilization. The ASi did not seem to reduce the risk of Clostridium difficile infection on the surgery wards (IRR 0.87, 95% CI 0.45, 1.69) compared to the medicine wards (IRR 0.42, 95% CI 0.28, 0.63). The ward-level burden of Clostridium difficile as measured by the ward's previous month's total CDI cases (CDI Lag) and the ward's current month's community-associated CDI cases (CA-CDI) was significantly associated with an increased risk of HA-CDI, with the estimated CDI Lag IRR of 1.21 (95% 1.15, 1.28) and the estimated CA-CDI IRR of 1.10 (95% CI 1.01, 1.20). The ward-level random intercept and slope coefficients were not significant. The final model demonstrated good fit. CONCLUSIONS: In this study, a daily prospective audit and feedback ASi resulted in a significant reduction in the risk of HA-CDI on the medicine wards, however, this effect was independent of an overall reduction in antibiotic utilization. In addition, the ward-level burden of Clostridium difficile was shown to significantly increase the risk of HA-CDI, reinforcing the importance of the environment as a source of HA-CDI.