Adverse drug reactions related to amoxicillin alone and in association with clavulanic acid: data from spontaneous reporting in Italy

Appropriate use of antibiotics for oral/dental conditions in older adults: a narrative review

OBJECTIVES

Considering the high rates in the use of antibiotics for oral/dental conditions in older patients and the rise in antimicrobial resistance, appropriate antibiotic prescription is important. This narrative review aimed to discuss the challenges and special considerations when prescribing antibiotics to older patients for oral/dental conditions.

METHODS

PubMed/MEDLINE, Scopus, Web of Science, and articles' reference lists were searched for antibiotics use for oral conditions by older patients. Moreover, scientific and professional organisations' official websites were searched for guidelines on antibiotic use in dentistry.

RESULTS

Despite several guidelines about the use of antibiotics in dentistry, specific information on their administration to older patients is missing. Relevant challenges include age-related changes in pharmacokinetics and pharmacodynamics, comorbidities and polypharmacy associated with low adherence, contraindications, adverse reactions, and drug-drug interactions. In unfit and frail older patients some antibiotics should be avoided, or doses should be adjusted, according to medical conditions or medications received. Amoxicillin, with doses adapted to renal function, is one of the safest options, while other antibiotics should be chosen with caution upon indications and individual patient characteristics.

CONCLUSIONS

Healthcare providers should prescribe antibiotics to unfit and frail older adults with caution, given the multitude of comorbidities and potential interactions with medications received. Further research is needed on the safe and effective use of antibiotics in older patients.

Pharmacovigilance Strategies to Address Resistance to Antibiotics and Inappropriate Use-A Narrative Review

The spread of antimicrobial resistance (AMR) is a global challenge. Close and continuous surveillance for quick detection of AMR can be difficult, especially in remote places. This narrative review focuses on the contributions of pharmacovigilance (PV) as an auxiliary tool for identifying and monitoring the ineffectiveness, resistance, and inappropriate use of antibiotics (ABs). The terms "drug ineffective", "therapeutic failure", "drug resistance", "pathogen resistance", and "multidrug resistance" were found in PV databases and dictionaries, denoting ineffectiveness. These terms cover a range of problems that should be better investigated because they are useful in warning about possible causes of AMR. "Medication errors", especially those related to dose and indication, and "Off-label use" are highlighted in the literature, suggesting inappropriate use of ABs. Hence, the included studies show that the terms of interest related to AMR and use are not only present but frequent in PV surveillance programs. This review illustrates the feasibility of using PV as a complementary tool for antimicrobial stewardship activities, especially in scenarios where other resources are scarce.

Hepatotoxicity of Antibiotics and Antifungals and Their Safe Use in Hepatic Impairment

Idiosyncratic drug-induced liver injury (DILI) is a rare and unpredictable form of hepatotoxicity. While its clinical course is usually benign, cases leading to liver transplantation or death can occur. Based on modern prospective registries, antimicrobials including antibiotics and antifungals are frequently implicated as common causes. Amoxicillin-clavulanate ranks as the most common cause for DILI in the Western World. Although the absolute risk of hepatotoxicity of these agents is low, as their usage is quite high, it is not uncommon for practitioners to encounter liver injury following the initiation of antibiotic or antifungal therapy. In this review article, mechanisms of hepatoxicity are presented. The adverse hepatic effects of well-established antibiotic and antifungal agents are described, including their frequency, severity, and pattern of injury and their HLA risks. We also review the drug labeling and prescription guidance from regulatory bodies, with a focus on individuals with hepatic impairment.

Nationwide survey on the management of pediatric pharyngitis in Italian emergency units

BACKGROUND

Acute pharyngitis is a frequent reason for primary care or emergency unit visits in children. Most available data on pharyngitis management come from primary care studies that demonstrate an underuse of microbiological tests, a tendency to over-prescribe antibiotics and a risk of antimicrobial resistance increase. However, a comprehensive understanding of acute pharyngitis management in emergency units is lacking. This study aimed to investigate the frequency of rapid antigen test use to diagnose acute pharyngitis, as well as other diagnostic approaches, the therapeutic attitude, and follow-up of children with this condition in the emergency units.

METHODS

A multicentric national study was conducted in Italian emergency departments between April and June 2022.

RESULTS

A total of 107 out of 131 invited units (response rate 82%), participated in the survey. The results showed that half of the units use a scoring system to diagnose pharyngitis, with the McIsaac score being the most commonly used. Most emergency units (56%) were not provided with a rapid antigen diagnostic test by their hospital, but the test was more frequently available in units visiting more than 10,000 children yearly (57% vs 33%, respectively, p = 0.02). Almost half (47%) of the units prescribe antibiotics in children with pharyngitis despite the lack of microbiologically confirmed cases of Group A β-hemolytic streptococcus. Finally, about 25% of units prescribe amoxicillin-clavulanic acid to treat Group A β-hemolytic streptococcus pharyngitis.

CONCLUSIONS

The study sheds light on the approach to pharyngitis in emergency units, providing valuable information to improve the appropriate management of acute pharyngitis in this setting. The routinary provision of rapid antigen tests in the hospitals could enhance the diagnostic and therapeutic approach to pharyngitis.

National Amoxicillin-Clavulanate Formulation Use Pattern: A Survey

OBJECTIVE

Five commercially available amoxicillin-clavulanate (AMC) ratio formulations contribute to ratio selection variability with efficacy and toxicity implications. The objective of this survey was to determine AMC formulation use patterns across the United States.

METHODS

A multicenter practitioner survey was distributed to multiple listservs (American College of Clinical Pharmacy pediatrics, infectious diseases, ambulatory care, pharmacy administration; American Society of Health-System Pharmacists; Pediatric Pharmacy Association members), and selected pediatric Vizient members in June 2019. Responses were screened for multiples within institutions. Repeated organization responses were identified (n = 37) and excluded if the duplicate matched another response from the same organization exactly (n = 0).

RESULTS

One hundred ninety independent responses were received. Nearly 62% of respondents represented a children's hospital within an acute care hospital; remainder being from stand-alone children's hospitals. Around 55% of respondents indicated prescribers were responsible for choosing the patient-specific formulation for inpatients. Nearly 70% of respondents indicated multiple formulations were available due to clinical need (efficacy, toxicity, measurable volume), whereas over 40% responded that the number of liquid formulations were limited to decrease the potential for error. Variability was demonstrated among institutions using ≥ 2 different formulations for acute otitis media (AOM), sinusitis, lower respiratory tract infection, skin and soft tissue infection, and urinary tract infection (33.6%, 37.3%, 41.5%, 35.8%, and 35.8%, respectively). The 14:1 formulation was the most common, but not exclusive, for AOM, sinusitis, and lower respiratory tract infections with 2.1%, 2.1%, and 2.6% of respondents indicating use of the 2:1 formulation and 10.9%, 15%, and 16.6% of respondents indicating use of the 4:1 formulation.

CONCLUSIONS

Significant AMC formulation selection variability exists across the United States.

Drug-induced tooth discoloration: An analysis of the US food and drug administration adverse event reporting system

Background: Certain drugs can cause intrinsic or extrinsic tooth discoloration, which is not only a clinical issue but also an esthetic problem. However, limited investigations have focused on drug-induced tooth discoloration. The present work aimed to determine the drugs causing tooth discoloration and to estimate their risks of causing tooth discoloration. Methods: An observational, retrospective, and pharmacovigilance analysis was conducted, in which we extracted adverse event (AE) reports involving tooth discoloration by using the data of the US Food and Drug Administration's Adverse Event Reporting System (FAERS) from the first quarter (Q1) of 2004 to the third quarter (Q3) of 2021. Disproportionality analyses were performed to examine risk signals for tooth discoloration and determine the drugs inducing tooth discoloration. Results: Based on predefined inclusion criteria, 1188 AE reports involving 302 suspected drugs were identified. After data mining, 25 drugs generated positive risk signals for tooth discoloration, of which 10 were anti-infectives for systemic use. The top reported drug was tetracycline (n = 106), followed by salmeterol and fluticasone (n = 68), amoxicillin (n = 60), chlorhexidine (n = 54), and nicotine (n = 52). Cetylpyridinium (PRR = 472.2, ROR = 502.5), tetracycline (PRR = 220.4, ROR = 277), stannous fluoride (PRR = 254.3, ROR = 262.8), hydrogen peroxide (PRR = 240.0, ROR = 247.6), and chlorhexidine (PRR = 107.0, ROR = 108.4) showed stronger associations with tooth discoloration than the remaining drugs. Of 625 AE reports involving 25 drugs with positive risk signals, tooth discoloration was mostly reported in patients aged 45-64 (n = 110) and ≤18 (n = 95), and 29.4% (192/652) of the reports recorded serious outcomes. Conclusion: This study revealed that certain drugs are significantly associated with tooth discoloration. Caution should be exercised when using these drugs, especially during pregnancy and early childhood.

Clinical features, diagnosis and management of amoxicillin-induced Kounis syndrome

Background: The available evidence suggests that amoxicillin is often associated with the occurrence of Kounis syndrome (KS). The purpose of this study is to explore the clinical characteristics of KS induced by amoxicillin.

Methods: We searched for case reports of amoxicillin-induced KS through Chinese and English databases from 1972 to May 2022.

Results: A total of 33 patients with KS were included, including 16 patients (48.5%) receiving amoxicillin treatment and 17 patients (51.5%) receiving amoxicillin-clavulanate. The median age was 58 years (range 13–82), 75.8% were from Europe and 81.8% were male. Nearly 70% of KS patients develop symptoms within 30 min after administration. Chest pain (63.6%) and allergic reaction (75.8%) were the most common clinical manifestations. Diagnostic evaluation revealed elevated troponin (72.7%), ST-segment elevation (81.2%) and coronary artery stenosis with thrombosis (53.6%). Thirty-two (97.0%) patients recovered completely after discontinuation of amoxicillin and treatments such as steroids and antihistamines.

Conclusion: KS is a rare adverse reaction of amoxicillin. Amoxicillin-induced KS should be considered when chest pain accompanied by allergic symptoms, electrocardiogram changes and or elevated levels of myocardial injury markers. Therapeutic management of KS requires simultaneous treatment of cardiac and allergic symptoms. Epinephrine should be used with caution in patients with suspected KS.

Descriptive Analysis of Adverse Drug Reactions Reports of the Most Consumed Antibiotics in Portugal, Prescribed for Upper Airway Infections

Adverse drug reactions (ADR) significantly impact mortality and morbidity and lead to high healthcare costs. Reporting ADR to regulatory authorities allows for monitoring the safety and efficacy profile of medicines on the market and for assessing the benefit–risk ratio. This retrospective study aims to characterize the ADR profile of the most consumed antibiotics in Portugal that are prescribed for upper airway infections and submitted to the EudraVigilance database. The variables were analyzed in an exploratory perspective, through absolute and relative frequencies, with emphasis on serious ADR. A total of 59,022 reports were analyzed of which 64.4% were classified as suspected serious ADR. According to serious ADR, the female sex (52.2%) and 18–64 age group (47.5%) prevail. Health professionals reported 87.8% of suspected serious ADR and European Economic Area (EEA) countries represented 50.8% of the reports. “Skin and subcutaneous tissue connections” (15.9%), “general disorders and administrations site conditions” (12%), and “gastrointestinal disorders” (9.8%) are the prevalent system organ classes. In 4.5% of the reports, patients had a fatal outcome. A periodic evaluation of the safety of the antibiotic should be performed to facilitate the development of guidelines and policies to reduce the frequency of serious ADR.

Pharmacokinetics of Clavulanic Acid in the Pediatric Population: A Systematic Literature Review

Background and Objective

Clavulanic acid is a commonly used β-lactam inhibitor in pediatrics for a variety of infections. Clear insight into its mode of action is lacking, however, and a target has not been identified. The dosing of clavulanic acid is currently based on that of the partner drug (amoxicillin or ticarcillin). Still, proper dosing of the compound is needed because clavulanic acid has been associated with adverse effects. In this systematic review, we aim to describe the current literature on the pharmacokinetics of clavulanic acid in the pediatric population

Methods

We performed a systematic search in MEDLINE, Embase.com, Cochrane Central, Google Scholar, and Web of Science. We included all published studies reporting pharmacokinetic data on clavulanic acid in neonates and children 0–18 years of age.

Results

The search resulted in 18 original studies that met the inclusion criteria. In general, the variation in drug exposure was large, which can be partly explained by differences in disease state, route of administration, or age. Unfortunately, the studies’ limited background information hampered in-depth assessment of the observed variability.

Conclusion

The pharmacokinetics of clavulanic acid in pediatric patients is highly variable, similar to reports in adults, but more pronounced. Significant knowledge gaps remain with regard to the population-specific explanation for this variability. Model-based pharmacokinetic studies that address both maturational and disease-specific changes in the pediatric population are therefore needed. Furthermore, additional pharmacodynamic studies are needed to define a clear target. The combined outcomes will eventually lead to pharmacokinetic-pharmacodynamic modeling of clavulanic acid and targeted exposure.

Clinical Trial Registration

PROSPERO CRD42020137253.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40262-022-01116-3.

Amoxicillin-associated Stevens-Johnson syndrome or toxic epidermal necrolysis: systematic review

Our aim was to explore and summarize available cases of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) suspected to be associated with amoxicillin reported in the literature. Electronic searches were conducted in several databases. Fifty-one publications describing a total of 64 patients who satisfied inclusion criteria were included in the review. The age of the patients ranged from 1.5-80 years (median: 24.5 years). TEN, SJS and SJS/TEN overlap were diagnosed in 30 (46.9%), 28 (43.8%) and 1 (1.6%) patients, respectively. SJS/TEN may occur promptly after administration of amoxicillin, but it could also be a delayed adverse effect. The total length of hospital stay ranged from 3-70 days (median: 16 days). Amoxicillin-induced SJS/TEN is accompanied by frequent occurrence of serious complications, long-term ocular and skin sequelae and high mortality rate. Clinicians should be aware that amoxicillin alone or combined with clavulanic acid can cause SJS/TEN in patients of all ages.

Antibiotic prescription for endodontic infections among Italian dental practitioners: what is the extent of over-prescription?

Objectives: Objectives of this study were to evaluate the pattern of antibiotic prescription for endodontic infections (EIs) among Italian dental practitioners (DPs), and to explore the role of potential predictors of antibiotic over-prescription. Methods: A nationwide cross-sectional survey was conducted between 1^st April to 30^th October 2019 using a structured questionnaire. Information was gathered on demographics and professional characteristics, and practices regarding antibiotic prescription both for therapeutic and prophylactic purposes. Results: Of the 1250 invited DPs, 563 answered the general questionnaire (response rate 52.6%). The proportions of DPs who prescribed an antibiotic without indication for therapeutic and prophylactic purposes is 33.3% and 30.2%, respectively. The acute alveolar abscess without systemic involvement represents the clinical scenario at high risk of over-prescription for therapeutic purposes. Possible predictors of over-prescribing included demographics and professional characteristics, and it was found to be higher in EIs without indication than in the cases in which the prescription is indicated for therapeutic purposes. The odds of over-prescription for prophylactic purposes were higher in the cases of acute apical periodontitis and lower in the cases of symptomatic irreversible pulpitis compared with acute and chronic alveolar abscess, in which the prescription is indicated. Conclusions: The main findings of the present study provide an up-to-date insight about the pattern of antibiotic prescriptions for EIs and evidence useful to identify opportunities to reduce over-prescription among DPs through tailored interventions. The development of practical antibiotic prescribing guidelines with a clear description of indications and regimens ease of use is strongly needed.

Prosthetic Joint Infection After Dental Work: Is the Correct Prophylaxis Being Prescribed? A Systematic Review

Background

Prosthetic joint infection (PJI) of total hip (THA) or total knee arthroplasty (TKA) after dental procedures is uncommon, and antibiotic prophylaxis remains controversial. For high-risk patients, the American Academy of Orthopedic Surgeons recommends amoxicillin prophylaxis. However, no systematic review of the literature of PJIs associated with dental procedures explores if amoxicillin is suitable for the reported organisms.

Methods

A librarian-assisted search of the major databases (PubMed, Medline, Embase, Scopus) identified 954 articles. Only case reports, case series, and reviews with patient level data were included. After exclusions, 79 articles were fully reviewed.

Results

Forty-four PJIs after dental procedures were identified, 22 in primary THA, 20 in primary TKA, one in revision THA, and one in a hip resurfacing procedure. Antibiotic prophylaxis was documented for 5 patients. The dental procedure was invasive in 35 (79.5%). Comorbidities were present in 17 patients (38.7%). The organisms reported were Streptococcus spp. in 44%, other aerobic gram-positives in 27%, anaerobic gram-positives in 18%, and gram-negative organisms in 11%. An estimated 46% of organisms may be resistant to amoxicillin. The outcomes of treatment were reported for 35 patients (79.5%). Twenty-seven patients (61.4%) had no clinical signs of PJI at the final follow-up visit.

Conclusions

Lower extremity PJI associated with dental procedures is often caused by organisms unlikely to be prevented with amoxicillin. Additional studies are warranted to determine the choice and efficacy of antibiotic prophylaxis to prevent dental-associated PJI in the highest risk patients. Insufficient data exist to recommend the optimal treatment for patients with PJI in THA and TKA associated with dental procedures.

Monitoring the community use of antibiotics in Italy within the National Action Plan on antimicrobial resistance

BACKGROUND

In Italy both the consumption of antibiotics and the prevalence of bacterial resistance are higher than in other European countries. In 2017, the first National Action Plan on Antimicrobial Resistance (PNCAR) was adopted in Italy. In response to the PNCAR two national reports on antibiotic use in the human setting have been published. This article's aim is to describe the pattern of antibiotic consumption in the community setting in Italy from 2013 to 2018.

METHODS

To analyse the consumption for reimbursed antibiotics dispensed by community pharmacies different data sources were used. Consumption was measured in terms of defined daily dose (DDD), prescriptions or prevalence of use.

RESULTS

In 2018, the consumption of antibiotics in Italy amounted to 16.1 DDD per 1000 inhabitants per day. The rates of consumption by geographical area were: 12.7 DDD in the north, 16.9 in the centre and 20.4 in the south. The use was greater in the extreme age groups than in the population aged from 20 to 64 years. The consumption was higher in winter season, with high peaks in the incidence of flu syndromes. In the paediatric population, a utilization rate of 1010 prescriptions per 1000 children, with a prevalence of use of 40.8%, was found.

CONCLUSION

The study provides useful information on the geographical variability of antibiotic use in Italy to guide decision makers in the introduction of tailored interventions, as suggested by PNCAR, aimed at promoting a more rational use of antibiotics for humans and reducing antimicrobial resistance.

Oral amoxicillin and amoxicillin-clavulanic acid: properties, indications and usage

BACKGROUND

Amoxicillin has been in use since the 1970s; it is the most widely used penicillin both alone and in combination with the β-lactamase clavulanic acid.

OBJECTIVES

In this narrative review, we re-examine the properties of oral amoxicillin and clavulanic acid and provide guidance on their use, with emphasis on the preferred use of amoxicillin alone.

SOURCES

Published medical literature (MEDLINE database via Pubmed).

CONTENT

While amoxicillin and clavulanic acid have similar half-lives, clavulanic acid is more protein bound and even less heat stable than amoxicillin, with primarily hepatic metabolism. It is also more strongly associated with gastrointestinal side effects, including Clostridium difficile infection, and, thus, in oral combination formulations, limits the maximum daily dose of amoxicillin that can be given. The first ratio for an amoxicillin-clavulanic acid combination was set at 4:1 due to clavulanic acid's high affinity for β-lactamases; ratios of 2:1, 7:1, 14:1 and 16:1 are currently available in various regions. Comparative effectiveness data for the different ratios are scarce. Amoxicillin-clavulanic acid is often used as empiric therapy for many of the World Health Organization's Priority Infectious Syndromes in adults and children, leading to extensive consumption, when some of these syndromes could be handled with a delayed antibiotic prescription approach or amoxicillin alone.

IMPLICATIONS

Using available epidemiological and pharmacokinetic data, we provide guidance on indications for amoxicillin versus amoxicillin-clavulanic acid and on optimal oral administration, including choice of combination ratio. More data are needed, particularly on heat stability, pharmacodynamic effects and emergence of resistance in 'real-world' clinical settings.

Managing knowledge for health care quality: An investigation of rational antibiotic use among Thai dentists

OBJECTIVES

Because of the irrational use of antibiotics, antimicrobial resistance is now a global concern that requires developing effective strategies against. The aim of this study was to assess the knowledge gap that causes the irrational use of antibiotics among Thai dentists.

METHODS

Thai dentists were asked to complete an online questionnaire regarding their knowledge, perception, and attitude towards rationale antibiotic use. The survey was conducted during November to December 2018.

RESULTS

Online questionnaires were completed by 588 dentists. Most respondents had a positive perception and were aware of the rational use of antibiotics. However, the use of antibiotics without proper indication and the lack of pharmacological knowledge were found. A mobile application was considered the most preferable approach to manage knowledge for rational drug use.

CONCLUSION

Irrational drug use among Thai dentists can be caused by lack of knowledge, attitude, and the perception of each dentist. Policy makers should promote self-learning through knowledge management strategies that can complement the pharmacology courses taught in dental school.

The use and misuse of antibiotics in dentistry: A scoping review

BACKGROUND

To describe antibiotic prescribing behaviors in dentistry, including clinical and nonclinical indications for their use, the type and regimen of antibiotics prescribed, and factors influencing their prescription, the authors conducted a scoping review.

TYPES OF STUDIES REVIEWED

The authors conducted a scoping review of published literature by searching multiple databases. Key search terms included dentist, antibiotic, antimicrobial, antibacterial, prophylaxis, prescription, pattern, habit, knowledge, and practice. Two authors independently reviewed titles and abstracts by using detailed eligibility criteria. The authors placed no restrictions on study design or publication year. The authors qualitatively assessed studies by using a modified version of the Center for Evidence-Based Management's critical appraisal of a survey checklist.

RESULTS

The authors identified 1,912 studies but considered only 118 studies eligible for review. Most included studies were either cross-sectional surveys (81 studies) or prescription audits (25 studies) from various geographic locations. Publication dates ranged from 1982 through 2017. The authors examined prophylactic and therapeutic antibiotic use in 48 and 29 studies, respectively. Another 29 studies examined the use of both prophylactic and therapeutic antibiotics in dentistry. Overall, dentists prescribed a wide variety of antibiotic regimens for various clinical and nonclinical indications. Dentists have acquired their prescribing knowledge from a variety of sources and have changed their antibiotic prescribing practices throughout their careers for various reasons.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Considering the seriousness of antibiotic resistance, the authors highlight trends in antibiotic prescribing practices, characterize factors contributing to the use and misuse of antibiotics in dentistry, provide insight into the importance of antibiotic stewardship in the oral health setting, and encourage dentists to reflect on their antibiotic prescription practices.

Adverse drug reaction monitoring during antimicrobial therapy for septicemia patients at a university hospital in New Delhi

BACKGROUND/AIMS

Adverse drug reaction (ADR) is an appreciably harmful or unpleasant reaction, resulting from an intervention related to the use of a medicinal product. The present study was conducted in order to monitor the frequency and severity of ADR during antimicrobial therapy of septicemia.

METHODS

A prospective, observational, and noncomparative study was conducted over a period of 6 months on patients of septicemia admitted at a university hospital. Naranjo algorithm scale was used for causality assessment. Severity assessment was done by Hartwig severity scale.

RESULTS

ADRs in selected hospitalized patients of septicemia was found to be in 26.5% of the study population. During the study period, 12 ADRs were confirmed occurring in 9, out of 34 admitted patients. Pediatric patients experienced maximum ADRs, 44.4%. Females experienced a significantly higher incidence of ADRs, 66.7%. According to Naranjo's probability scale, 8.3% of ADRs were found to be definite, 58.3% as probable, and 33.3% as possible. A higher proportion of these ADRs, 66.7% were preventable in nature. Severity assessment showed that more than half of ADRs were moderate. Teicoplanin was found to be the commonest antimicrobial agent associated with ADRs, followed by gemifloxacin and ofloxacin.

CONCLUSION

The incidence and severity of ADRs observed in the present study was substantially high indicating the need of extra vigilant during the antimicrobial therapy of septicemia.

Is Antibiotic Prophylaxis Cost-effective for Dental Patients Following Total Knee Arthroplasty?

Introduction:

Routine antibiotic prophylaxis (AP) to prevent prosthetic joint infection remains controversial. The lack of prophylaxis guideline consensus from the American Academy of Orthopaedic Surgeons (AAOS) and the American Dental Association (ADA) contributes to clinician confusion.

Objectives:

This cost-effectiveness decision model informs the AP debate and guideline development by comparing the benefits, harms, and costs of alternative prophylaxis strategies.

Methods:

A Markov state-transition model was developed comparing lifetime health outcomes and costs of alternative AP strategies for dental patients aged 65 y with a history of total knee arthroplasty (TKA). Based on our interpretation of AP recommendations from the AAOS and ADA, incremental cost-effectiveness ratios were calculated to compare the following strategies: no AP, AP for the first 2 y after a TKA, and lifetime AP.

Results:

The no-AP strategy had the lowest average lifetime costs ($17,119) and quality-adjusted life years (11.2151). Compared with a no-prophylaxis strategy, the 2-y AP strategy had incremental costs of $56 and 0.0006 QALYs gained and was cost-effective (incremental cost-effectiveness ratio = $95,100) when a willingness-to-pay threshold of $100,000 per quality-adjusted life year was used. Based on the results of 1-way sensitivity analysis, the no-AP strategy was cost-effective when we modestly increased base case amoxicillin adverse event estimates that were substantially lower than estimates reported in previous models. When plausible combinations of important model parameters were varied, model results suggested that there may be clinical scenarios when AP may be appropriate for some medically at-risk patient populations.

Conclusion:

The results of cost-effectiveness decision modeling generally support questioning routine AP for dental patients with TKA. Sensitivity analyses suggest that prophylaxis may be cost-effective for patient populations with a higher medical risk of infection. This finding is consistent with the recommendations of the 2015 ADA practice guideline and the appropriate use criteria jointly developed by the AAOS and the ADA.

Knowledge Transfer Statement:

The results of this decision modeling research support the contention that routine AP before invasive dental procedures to prevent prosthetic joint infection may not be cost-effective for patients without medical conditions, potentially conferring a higher infection risk. Model sensitivity analyses suggest that there may be clinical situations when medically at-risk patients benefit from AP.

Impact of the 10-valent pneumococcal conjugate vaccine on antimicrobial prescriptions in young children: a whole population study

Background

Antimicrobial resistance is a public-health threat and antimicrobial consumption is the main contributor. The ten-valent pneumococcal conjugate vaccine (PHiD-CV10) was introduced into the Icelandic vaccination program in 2011.

The aim was to estimate the vaccine impact of PHiD-CV10 on outpatient antimicrobial prescriptions in children.

Methods

Eleven Icelandic birth-cohorts (2005–2015) were followed from birth until three years of age or to the end of the study period (December 31, 2016). Birth-cohorts were grouped as vaccine non-eligible (VNEC, 2005–2010) or vaccine eligible (VEC, 2011–2015). Data on primary care visits for respiratory infections and antimicrobial prescriptions were extracted from two national registers. Using national identification numbers, prescriptions were linked to physician visits if filled within three days of the visit. Incidence rates and incidence rate ratios between VNEC and VEC were calculated. An Andersen-Gill model was used to model the individual level data, accounting for repeated events and censoring. Vaccine impact was calculated as (1 – Hazard Ratio) × 100%.

Results

Included were 53,510 children who contributed 151,992 person-years of follow-up and filled 231,660 antimicrobial prescriptions. The incidence rate was significantly lower in the VEC compared to the VNEC, 144.5 and 157.2 prescriptions per 100 person-years respectively (IRR 0.92, 95%CI 0.91–0.93). Children in VEC were more likely to have filled zero (IRR 1.16 (95%CI 1.10–1.23) and 1–4 (IRR 1.08 95%CI 1.06–1.11) prescriptions compared to children in VNEC. The vaccine impact of PHiD-CV10 against all-cause antimicrobial prescriptions was 5.8% (95%CI 1.6–9.8%).When only considering acute otitis media-associated prescriptions, the vaccine impact was 21.8% (95%CI 11.5–30.9%).

Conclusion

The introduction of PHiD-CV10 lead to reduced antimicrobial use in children, mainly by reducing acute otitis media episodes. This intervention therefore reduces both disease burden and could slow the spread of antimicrobial resistance.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3416-y) contains supplementary material, which is available to authorized users.

A systematic review of randomised clinical trials for oral antibiotic treatment of acute pyelonephritis

There is increasing resistance to the oral antibiotics currently recommended for the treatment of pyelonephritis, and increased healthcare costs are associated with the reliance on alternative intravenous agents. We, therefore, performed a systematic review of randomised controlled trials to determine the clinical efficacy and safety of oral antibiotics for the treatment of pyelonephritis in adults. A search of four major medical databases (MEDLINE, Embase+ Embase classic, CENTRAL and Cochrane Database for Systematic Reviews) in addition to manual reference searching of relevant reviews was conducted. Clinical cure and adverse event rates were reported, and trial quality and bias were assessed. A total of 277 studies were reviewed; five studies matched all eligibility criteria and were included. Antibiotics included were cefaclor, ciprofloxacin, gatifloxacin, levofloxacin, lomefloxacin, loracarbef, norfloxacin, rufloxacin and trimethoprim-sulfamethoxazole. In included studies, the clinical success of the outpatient treatment of pyelonephritis by cefaclor, ciprofloxacin and norfloxacin at 4 to 6 weeks was comparable at between 83 to 95%. Relatively high rates of adverse events were noted in a trial of ciprofloxacin (24%) and trimethoprim-sulfamethoxazole (33%). Significant heterogeneity between all aspects of the trial designs was identified, with all studies having a potential for bias. This review demonstrates a need for high-quality clinical trials into the oral antibiotic treatment of pyelonephritis, with more consistent designs and reporting of outcomes. There are data to support further research into oral norfloxacin and cefaclor for the outpatient treatment of pyelonephritis in adults.

Part 1. Current prescribing trends of antibiotics by dentists in Australia from 2013 to 2016

BACKGROUND

Literature has shown dentists tend to overprescribe antibiotics and do not always prescribe in accordance with recommended guidelines. Unnecessary prescribing is one major factor that contributes to the development of antibiotic resistance. The aim of the present study was to assess the antibacterial prescribing patterns of dentists in Australia from 2013 to 2016.

METHODS

Data on dental antibacterial prescriptions dispensed under the Pharmaceutical Benefits Scheme (PBS) from 2013 to 2016 was accessed and prescribing trends analysed. The prescribing rates were standardized to the dose and population.

RESULTS

There was a slight decrease in the dispensed use of most antibacterials from 2013 to 2016, but there was a significant increase in the dispensed use of amoxicillin/clavulanic acid of 11.2%. Amoxicillin was the most commonly dispensed antibiotic, accounting for approximately 65% of all antibacterials from 2013 to 2016, while phenoxymethylpenicillin accounted for only 1.4% of prescriptions in 2016. There were low but significant quantities of dispensed antibiotic prescriptions that do not fit with current guidelines.

CONCLUSIONS

The data suggest that dentists in Australia are prescribing some antibiotics inappropriately and there is a preference for moderate- to broad-spectrum agents. The current PBS dental schedule is inconsistent with prescribing guidelines and may contribute to inappropriate prescribing.

Adverse Effects of Amoxicillin for Acute Lower Respiratory Tract Infection in Primary Care: Secondary and Subgroup Analysis of a Randomised Clinical Trial

A European placebo-controlled trial of antibiotic treatment for lower respiratory tract infection (LRTI) conducted in 16 primary care practices networks recruited participants between November 2007 and April 2010, and found adverse events (AEs) occurred more often in patients prescribed amoxicillin compared to placebo. This secondary analysis explores the causal relationship and estimates specific AEs (diarrhoea, nausea, rash) due to amoxicillin treatment for LRTI, and if any subgroup is at increased risk of any or a specific AE. A total of 2061 patients were randomly assigned to amoxicillin (1038) and placebo (1023); 595 (28%) were 60 and older. A significantly higher proportion of any AEs (diarrhoea or nausea or rash) (OR = 1.31, 95% CI 1.05–1.64, number needed to harm (NNH) = 24) and of diarrhoea (OR 1.43 95% CI 1.08–1.90, NNH = 29) was reported in the amoxicillin group during the first week after randomisation. Subgroup analysis showed rash was significantly more often reported in males prescribed amoxicillin (interaction term 3.72 95% CI 1.22–11.36; OR of amoxicillin in males 2.79 (95% CI 1.08–7.22). No other subgroup at higher risk was identified. Although the study was not powered for subgroup analysis, this analysis suggests that most patients are likely to be equally harmed when prescribed antibiotics.

An Uncommon Side Effect of a Commonly Used Antibiotic: Amoxicillin-Clavulanic Acid Induced Hepatitis

Amoxicillin-Clavulanic acid continues to be one of the most commonly used antibiotic combinations. Hepatic injury due to this antibiotic is rare. We report a case of amoxicillin-clavulanic acid induced hepatitis causing painless jaundice to bring to attention this rare side effect of this commonly used antibiotic. This is a case of a 62-year-old Caucasian female, who presented with acute onset severe painless jaundice, nausea, vomiting, and pruritus of less than 1-week duration. She had completed a course of amoxicillin-clavulanic acid 3 weeks prior to presentation. A careful history pointed to this simple diagnosis. It may be easily missed without an in-depth history and the patient may be subjected to unnecessary expensive tests. This case is reported to highlight cost conscious care by keeping in mind a rare side effect of the commonly used antibiotic.

Severe Drug-Induced Liver Injury as an Adverse Drug Event of Antibiotics: A Case Report and Review of the Literature

Drug-induced liver injury is one of the main reasons for acute liver failure. We report the case of a young patient who experienced a drug-induced liver injury resulting in life-threatening acute liver failure after treatment with different antibiotics (amoxicillin, ciprofloxacin, cefazolin, clindamycin) and acetaminophen, or a combination of these drugs. Moreover, we provide an overview of the hepatotoxic potential of these drugs.

Genetic Factors Influencing Drug-Induced Liver Injury: Do They Have a Role in Prevention and Diagnosis?

Purpose of Review

The pathogenesis of DILI is currently unknown; however, research has shown strong genetic associations with some DILIs. This paper describes the variant alleles uncovered by GWAS and discusses their potential role as susceptibility biomarkers.

Recent Findings

An association with HLADRB1*15:01 and amoxicillin/clavulanate DILI has been shown by a number of research groups. The presence of the HLA-B*57:01 allele has been associated with an 81-fold increased risk of flucloxacillin DILI. The HLA-B*35:02 allele has significant association with minocycline DILI.

Summary

With the exception of abacavir for HIV therapy, no other prospective genetic screening tests have met the threshold for clinical application. This is largely because DILI incidence is too low to warrant the cost and effort associated with testing. Perhaps, with the development of personalised medicine, a panel of genes for disease susceptibility, drug efficacy and adverse reactions could be tested once off. This would change the cost-effectiveness paradigm, personalise healthcare and reduce DILI risk by avoiding medications in patients with specific HLA alleles.

Amoxycillin and clavulanic acid induced Stevens-Johnson syndrome: A case report

Stevens-Johnson syndrome (SJS) is an immune mediated hypersensitivity reaction. Significant involvement of oral, nasal, eye, vaginal, urethral, GI and lower respiratory tract mucous membrane may develop. It is usually a reaction due to a medication or due to an infection. In 95 % of case reports, drugs were found to be an important cause for the development of SJS. In this case report, a 32 year old female reported chief complaint of itch skin eruptions all over the body along with erosive lesions on tongue, lips, buccal mucosa and genital mucosa. The reaction occurred after administration of augmentin (containing amoxycillin and clavulanic acid). She was treated with antimicrobials, antiallergics and conservative management. The patient improved and was discharged from the hospital. Causality assessment using Naranjo Adverse Drug Reaction Probability Scale revealed that amoxycillin and clavulanic acid combination was a possible cause for the adverse reaction with a score of 4.

Mechanisms of Drug-Induced Hepatotoxicity

Drug-induced hepatotoxicity (DIH) is a significant cause of acute liver failure and liver transplantation. Diagnosis is challenging due to the idiosyncratic nature, its presentation in the form of other liver disease, and the lack of a definite diagnostic criteria. Generation of reactive metabolites, oxidative stress, and mitochondrial dysfunction are common mechanisms involved in DIH. Certain risk factors associated with a drug and within an individual further predispose patients to DIH.

Assessing the quality of paediatric antibiotic prescribing by community paediatricians: a database analysis of prescribing in Lombardy

OBJECTIVE

To evaluate the quality of paediatricians' antibiotic prescribing using administrative databases.

METHODS

The data source was the database of reimbursed prescriptions of the Lombardy Region, Italy. Children 1-13 years were included. An index prescription was defined as the first antibiotic prescription during a year period (2011) that occurred without previous, recent, antibiotic prescriptions or hospital or emergency department admissions. The A indicator was the percentage of children, cared for by paediatricians, receiving amoxicillin at the index prescription (minimum target 50%). The B indicator was the percentage of children receiving exclusively non-penicillin antibiotics in unrelated infection episodes (maximum target 10%). Indicators were evaluated for each prescriber and geographical area.

RESULTS

Overall 424 280 children (cared for by 1164 paediatricians) received an index prescription and were included in the study. Amoxicillin alone was prescribed at the index prescription only to 23.6% of children (7.9%-46.3% within different areas of the region).The percentage of paediatricians who reached the target for the quality indicators was low (12.8% A indicator; 54.0% B indicator; 11.3% both). Almost half of the paediatricians (44.5%) showed inadequate quality of antibiotic prescribing, failing to reach the target for both indicators. Quality of prescribing was about four times worse in high prescribers and younger paediatricians. A geographical cluster of paediatricians reaching the target for both indicators was identified. These paediatricians had, for several years, previously been involved in educational programme.

CONCLUSIONS

Quality of prescribing was generally unsatisfactory, but increased in a group of paediatricians previously involved in educational interventions and increased with increasing age. Further studies are warranted in order to validate these promising indicators as a benchmarking tool in other studies, when diagnosis is unknown.

Drug-induced liver injury

Drug-induced liver injury (DILI) remains the most common cause of acute liver failure (ALF) in the western world. Excluding paracetamol overdose, nearly all DILI encountered in the clinical setting is idiosyncratic in nature because affected individuals represent only a small proportion of those treated with such drugs. In many cases, the mechanism for idiosyncrasy is immune-mediation and is often identified by genetic risk determined by human leukocyte antigen variants. In the absence of diagnostic tests and/or biomarkers, the diagnosis of DILI requires a high index of suspicion after diligently excluding other causes of abnormal liver tests. Antibiotics are the class of drugs most frequently associated with idiosyncratic DILI, although recent studies indicate that herbal and dietary supplements are an increasingly recognised cause. It is imperative that upon development of DILI the culprit drug be discontinued, especially in the presence of elevated transaminases (aspartate aminotransferase/alanine aminotransferase ratio ≥5 times the upper limit of normal) and/or jaundice. Risk factors for the development ALF include hepatocellular DILI and female gender, the treatment being supportive with some benefit of N-acetylcysteine in the early stages. In view of the poor transplant-free survival in idiosyncratic DILI, early consideration for liver transplant is mandatory.

Does the antibiotic amoxicillin affect haemocyte parameters in non-target aquatic invertebrates? The clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis as model organisms

Amoxicillin (AMX) is one of the most widely used antibiotics worldwide, and its levels in aquatic ecosystems are expected to be detectable. At present, information concerning the toxic effects of AMX on non-target aquatic organisms, such as bivalves, is scarce. Consequently, in this study, we investigated for the first time the effects of AMX on the haemocyte parameters of two bivalve species, the clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis, which share the same habitat in the Lagoon of Venice, in order to compare the relative sensitivity of the two species. The bivalves were exposed to 100, 200 and 400 μg AMX/L for 1, 3 and 7 days, and the effects on the total haemocyte count (THC), the diameter and volume of the haemocytes, haemocyte proliferation, lactate dehydrogenase (LDH) activity in cell-free haemolymph, the haemolymph pH, and the formation of micronuclei were evaluated. The actual concentrations of AMX in the seawater samples from the experimental tanks were also measured. Overall, the obtained results demonstrated that AMX affected slightly the haemocyte parameters of bivalves. In addition, no clear differences in terms of sensitivity to AMX exposure were recorded between the two bivalve species.

Systematic Review and Meta-Analysis: Macrolides- and Amoxicillin/Clavulanate-induced Acute Liver Injury

Antibacterials are frequently associated with idiosyncratic drug-induced liver injury (DILI). The objective of this study was to estimate the risk of macrolides and amoxicillin/clavulanate (AMC) on DILI. We conducted a systematic review (SR) and meta-analysis (MA) with studies retrieved from PubMed, Cochrane Library Plus, Web of Knowledge, clinicaltrials.gov, Livertox and Toxline (1980-2014). We searched for macrolides, AMC and MeSH and synonym terms for DILI. We included all study designs except case reports/series, all population ages and studies with a placebo/non-user comparator. We summarized the evidence with a random-effects MA. Quality of the studies was appraised with a checklist developed for SR of adverse effects. Heterogeneity and publication bias were assessed with different exploratory tools. We finally included 10 (two randomized clinical trials, six case-control, one cohort and one case-population studies) and 9 (case-population excluded) articles in the SR and MA, respectively. The overall summary relative risk of DILI for macrolides was 2.85 [95% confidence interval (CI) 1.81-4.47], p < 0.0001, I(2) = 57%. Three studies were perceived to be missing in the area of low statistical significance. Year of study and selected exposure window partly explained the variability between studies. For AMC, the risk of DILI was 9.38 (95% CI 0.65-135.41) p = 0.3, I2 = 95%. In conclusion, although spontaneous reports and case series have long established an association between macrolides and AMC with acute liver injury, these SR and MA have assessed the magnitude of this association. The low incidence of DILI and the therapeutic place of these antibiotics might tilt the balance in favour of their benefits.

The Role of Chronic Exposure to Amoxicillin/Clavulanic Acid on the Developmental Enamel Defects in Mice

Amoxicillin used in early childhood may be associated with enamel hypomineralization. Our aim was to assess disturbances of amelogenesis in mice lower incisors induced by chronic administration of amoxicillin/clavulanic acid (AMC). Twenty-eight C57BL/6 male mice, of similar age, randomly divided into a control and 3 treatment groups ( n = 7) received subcutaneous injection, once per day, for 60 days: 50, 100, and 150 mg/kg BW of AMC. Scanning electron microscopy/energy dispersive X-ray spectroscopy analysis in AMC treatment groups showed higher content in F and a decrease in P and Ca. Morphology changes ranged from scratched patterns, and small isolated pits-like enamel loss, to generalized demineralized enamel surface, giving a rough, foamy, scaly, or even cracked eggshell appearance to the affected areas. Histological analysis showed disturbances of maturation ameloblasts, which were less organized, with increased amounts of clear vacuoles in the cytoplasm and slightly more elongated and less condensed nucleus. Additionally, they were often detached from the enamel matrix. Transitional ameloblasts formed underlying the cysts of varied sizes. In conclusion, AMC dose-dependently affect ameloblast functions especially in the maturation phase, causing hypomineralized enamel formation with quantitative and/or qualitative defects.

Use of Antibiotics in Pediatrics: 8-Years Survey in Italian Hospitals

Objectives

To evaluate antibiotic consumption in the pediatric wards of Emilia-Romagna Region, from 2004 to 2011, with a focus on the antibiotics reserved to the most serious infections, and to analyse the ADRs reported for antibiotics by the pediatric wards of Emilia-Romagna hospitals.

Methods

Reference population was represented by all the patients (0–14 years old) admitted to the pediatric wards of all the hospitals of Emilia-Romagna Region. Drug consumption was expressed as number of DDDs per 100 Bed-Days (BD) and data were analysed by active substance, by therapeutic subgroups or by ward type. The time trends of antibiotic consumption were statistically analysed by linear regression. All the suspected ADR reports associated with antibiotics, reported between January 2004 and December 2011 were drawn by the Italian Spontaneous Reporting Database.

Results

Overall antibiotic consumption showed only a slight increase (p = 0.224). Among the pediatric wards, pediatric surgery showed the highest increase from 2004 to 2011 (p = 0.011). Penicillins and β-lactamase inhibitors was the first therapeutic group with a statistically significant increase over years (p = 0.038), whereas penicillins with extended spectrum presented a statistically significant reduction (p = 0.008). Moreover, only 5 drugs out of the 8 antibiotics reserved to the most serious infections were used. Pharmacovigilance data showed 27 spontaneous ADR reports associated to ATC J01 drugs. Amoxicillin/clavulanic acid had the highest number of ADR reports (n = 7).

Conclusions

The steadily increasing consumption in penicillins and β-lactamase inhibitors, in association with a considerable decrease of plain penicillins, raises a serious concern. Pharmacovigilance reports seem to suggest a safe use of antibiotics in the hospital setting of Emilia-Romagna. Further studies to investigate the reason for prescribing antibiotics in children inpatients are needed.

Drug-Induced Liver Injury

CONTEXT

Drug-induced liver injury (DILI) represents a diverse set of responses following exposure to any manufactured or naturally occurring chemical compound. Drug-induced liver injury is of major concern owing to the ever increasing number of compounds introduced into the market for treatment of various diseases as well as the increasing popularity of herbals, which lend themselves to self-medication but are not rigorously regulated.

OBJECTIVE

To provide an overview of the prevalence, classification, and diagnosis of DILI with emphasis on pathogenesis and the role of a liver biopsy. To focus on the most common, emerging, and herbal agents that cause DILI with emphasis on the histologic pattern of injury observed.

DATA SOURCES

A review of the literature was drawn from the PubMed (US National Library of Medicine) repository, textbooks, and online databases. All figures were taken from cases seen at our tertiary referral center, which is 1 of 12 participating sites in the National Institutes of Health-funded Drug-Induced Liver Injury Network.

CONCLUSIONS

Drug-induced liver injury due to prescription, over-the-counter, and herbal products is a major cause of liver disease in the United States and around the world. Diagnosis of DILI is challenging because there is no single clinical, laboratory, or histologic feature specific to DILI. Accurate diagnosis requires establishing a causal relationship with the suspected agent and excluding competing causes of liver injury. The liver biopsy is an essential component in the management of DILI by offering clues to the underlying pathogenesis, providing prognostic information, and guiding therapy.

A study of cutaneous adverse drug reactions at a tertiary center in Jammu, India

Aim:

The aim was to study various morphological patterns of cutaneous adverse drug reactions (CADRs) and identify the culprit drug or drugs by establishing a causal link using Naranjo adverse drug reaction probability scale.

Materials and Methods:

The study was carried out between November 2010 and November 2011 at the Department of Dermatology, Government Medical College, Jammu. A total of 150 patients with CADR reporting to the dermatology department or referred from other departments were evaluated. Detailed history, clinical examination, hematological, and biochemical investigations were recorded. The venereal disease research laboratory test, HIV (ELISA), and histopathological examination were done wherever indicated.

Results:

A total of 150 patients were evaluated after applying the inclusion and exclusion criteria. The mean age of the patients with CADRs was 33.26 years. A majority of patients (30.6%) were in the age group of 21–30 years. The male to female ratio was 1.7:1.2. The most common CADRs were fixed drug eruption in 33.3% of patients followed by urticaria in 17.3%, and maculopapular rash in 13.3%. The most common classes of drugs implicated were antimicrobials in 40% of patients followed by nonsteroidal antiinflammatory drugs in 35.3%. The Naranjo adverse drug reaction probability scale indicated probable association of 77.3%, highly probable association of 12.6%, and 1% possible association with the implicated drugs.

Conclusion:

The pattern of CADRs and the drugs causing them is remarkably different in our population. Knowledge of these drug reactions, their causative drugs, and prognostic indicators is essential for the clinician.

Comparative trial between the use of amoxicillin and amoxicillin clavulanate in the removal of third molars

Objectives: The purpose of this study was to compare the use of amoxicillin (1g) vs amoxicillin and clavulanate (875/125mg) after extraction of retained third molars for prevention of infectious complications. Study Design: The study involved 546 patients attending for removal a retained third molar and divided in to two groups: Group 1 - amoxicillin and clavunate (875/125mg) group (n=257) and Group 2 - amoxicillin (1g) group (n=289). All patients were recalled for investigating the possibility of infection, presence of diarrhea and further analgesic intake. Results: From a total of 546 patients, the frequency of infection was 1.4%, without no statistically differences between the two groups. Group 1 showed statistically higher presence of patients with gastrointestinal complications (p>0.05). In 546 patients, 2.7% of patients reported severe pain that would not relieve with medication. Conclusions: The results of our study show that the use of amoxicillin (1g) and amoxicillin and clavunate (875/125mg) is similar efficacious in preventing infection after retained third molar extraction but amoxicillin and clavunate (875/125mg) produces more gastrointestinal discomfort.

Key words:Amoxicillin, clavulanate, third molars, complications.

No evident association between efavirenz use and suicidality was identified from a disproportionality analysis using the FAERS database

OBJECTIVE

To assess the potential association of selected antiretrovirals (ARVs), including efavirenz, with suicidality.

DESIGN

Retrospective analysis of the Food and Drug Administration Adverse Event Reporting System (FAERS), by performing a Multi-Item Gamma Poisson Shrinker (MGPS) disproportionality analysis.

METHODS

MGPS disproportionality analysis, a technique to identify associations between drugs and adverse events, was performed using cumulative data from the FAERS database collected up to August 2012. This method yields an Empirical Bayesian Geometric Mean score and corresponding 90% confidence interval (EB05, EB95). EB05 scores ≥ 2 were pre-defined as a signal for a potential drug-event association. The FAERS database includes spontaneous adverse-event reports from consumers and healthcare professionals. All FAERS reports of suicidality (including suicidal ideation, suicide attempt and completed suicide or a composite of these) in patients taking efavirenz (as single agent or in fixed-dose combination), atazanavir, darunavir, etravirine, nevirapine and raltegravir were identified. A number of parallel analyses were performed to assess the validity of the methodology: fluoxetine and sertraline, antidepressants with a known association with suicidality, and raltegravir, an ARV with rhabdomyolysis and myopathy listed as "uncommon" events in the US-prescribing information.

RESULTS

A total of 29,856 adverse event reports were identified among patients receiving efavirenz, atazanavir, darunavir, etravirine, nevirapine and raltegravir, of which 457 were reports of suicidality events. EB05 scores observed for the composite suicidality term for efavirenz (EB05=0.796), and other ARVs (EB05=0.279-0.368), were below the pre-defined threshold. Fluoxetine and sertraline gave EB05 scores for suicidality >2. Raltegravir gave EB05 scores >2 for myopathy and rhabdomyolysis.

CONCLUSIONS

The pre-determined threshold for signals for suicidality, including suicidal ideation, suicide attempt, completed suicide and a composite suicidality endpoint, was not exceeded for efavirenz and other ARVs in this analysis. Efavirenz has been associated with suicidality in clinical trials. Further studies that adjust for confounding factors are needed to better understand any potential association with ARVs and suicidality.

Is the standard dose of amoxicillin-clavulanic acid sufficient?

Background

The pharmacodynamic (PD) efficacy target of amoxicillin is 40% time above the minimal inhibition concentration (40%T > MIC). Recent studies of other antibiotics have shown that PD-efficacy targets are not always reached. The aim of this study was to evaluate the percentage of hospitalised patients, using amoxicillin/clavulanic acid intravenously (iv), that reach the pharmacodynamic efficacy target 40%T > MIC. Additionally, the association of demographic anthropomorphic and clinical parameters with the pharmacokinetics and pharmacodynamics of amoxicillin were determined.

Methods

In serum of 57 hospitalised patients amoxicillin concentrations were measured using high performance liquid chromatography. Patients were older than 18 years and most patients had an abdominal infection. The standard amoxicillin/clavulanic acid dose was 4 times a day 1000/200 mg iv. Pharmacokinetic parameters were calculated with maximum a posteriori Bayesian estimation (MW\Pharm 3.60). A one-compartment open model was used. Individual dosing simulations were performed with MW\Pharm.

Results

In our study population, the mean (±SD) age was 67 (±16) years and the mean clearance corrected for bodyweight was 0.17 (±0.07) L/h/kg. Only, 65% of the patients reached the proposed amoxicillin 40%T > MIC with amoxicillin/clavulanic acid for bacterial MICs of 8 mg/L. A computer simulated increase of the standard dose to 6 times daily, increased this percentage to 95%. In this small study group 40%T > MIC was not associated with clinical or microbiological cure.

Conclusion

A substantial proportion of the hospitalised patients did not reach the 40%T > MIC with the standard dose amoxicillin/clavulanic acid for a bacterial MIC of 8 mg/L. Therefore, we suggest increasing the standard dose of amoxicillin/clavulanic acid to 6 times a day in patients with severe Enterobacteriaceae infections.

Trial registration

Trial registration number: NTR1725 16^th march 2009.

Idiopathic acute liver injury in paediatric outpatients: incidence and signal detection in two European countries

BACKGROUND

Acute liver failure is idiopathic and drug-related in, respectively, around 50 and 15 % of children. Population-based, epidemiologic data about the pattern of disease manifestation and incidence of less severe acute liver injury, either idiopathic or potentially drug-attributed are limited in children and adolescents.

OBJECTIVES

(i) To assess the incidence of idiopathic acute liver injury (ALI) and its clinical features in children and adolescent outpatients; and (ii) to investigate the role of the drug as a potential cause of ALI which is considered idiopathic.

METHODS

A retrospective cohort study was performed during the years 2000-2008. Data were retrieved from three longitudinal electronic healthcare databases in two European countries: Pedianet and Health Search/CSD Longitudinal Patient Database from Italy and the Integrated Primary Care Information database from The Netherlands. Cases of idiopathic acute liver injury in population aged <18 years were identified by exclusion of all competing causes of liver injury (e.g. viral, autoimmune hepatitis), according to CIOMS criteria. The potential role of drug exposure as actual underlying cause of idiopathic ALI was detected through signal detection mining techniques. Both pooled and country-specific incidence rates [IR/100,000 person-years (PYs)] of idiopathic ALI and pooled adjusted rate ratios (RR) of drugs identified as a potential cause of idiopathic ALI, plus 95 % confidence intervals (CI) were estimated using the custom-built software Jerboa.

RESULTS

Among 785 definite cases of idiopathic ALI, the pooled IR was 62.4/100,000 PYs (95 % CI 58.1-66.8). The country-specific IR was higher in Italy (73.0/100,000 PYs, 95 % CI 67.8-78.4) than in The Netherlands (21.0/100,000 PYs, 95 % CI 16.0-27.2) and increased with age in both countries. Isolated elevations of liver enzymes were reported in around two-thirds of cases in Italy, while in The Netherlands the cases were more often identified by a combination of signs/symptoms. Among drugs detected as potential underlying cause of idiopathic ALI, clarithromycin (RR 25.9, 95 % CI 13.4-50), amoxicillin/clavulanic acid (RR 18.6, 95 % CI 11.3-30.6), and amoxicillin (RR 7.5, 95 % CI 3.4-16.8) were associated with the highest risk compared to non-use.

CONCLUSION

The incidence of idiopathic ALI in paediatrics is relatively low and comparable with adults. Clinical presentations differ between the two European countries. Signal detection in healthcare databases allowed identifying antibiotics as the drugs mostly associated with ALI with apparently unknown aetiology.

Acute cholestatic hepatitis caused by amoxicillin/clavulanate

Amoxicillin/clavulanate is a synthetic penicillin that is currently commonly used, especially for the treatment of respiratory and cutaneous infections. In general, it is a well-tolerated oral antibiotic. However, amoxicillin/clavulanate can cause adverse effects, mainly cutaneous, gastrointestinal, hepatic and hematologic, in some cases. Presented here is a case report of a 63-year-old male patient who developed cholestatic hepatitis after recent use of amoxicillin/clavulanate. After 6 wk of prolonged use of the drug, he began to show signs of cholestatic icterus and developed severe hyperbilirubinemia (total bilirubin > 300 mg/L). Diagnostic investigation was conducted by ultrasonography of the upper abdomen, serum tests for infection history, laboratory screening of autoimmune diseases, nuclear magnetic resonance (NMR) of the abdomen with bile duct-NMR and transcutaneous liver biopsy guided by ultrasound. The duration of disease was approximately 4 mo, with complete resolution of symptoms and laboratory changes at the end of that time period. Specific treatment was not instituted, only a combination of anti-emetic (metoclopramide) and cholestyramine for pruritus.

Postmarketing safety surveillance : where does signal detection using electronic healthcare records fit into the big picture?

The safety profile of a drug evolves over its lifetime on the market; there are bound to be changes in the circumstances of a drug's clinical use which may give rise to previously unobserved adverse effects, hence necessitating surveillance postmarketing. Postmarketing surveillance has traditionally been carried out by systematic manual review of spontaneous reports of adverse drug reactions. Vast improvements in computing capabilities have provided opportunities to automate signal detection, and several worldwide initiatives are exploring new approaches to facilitate earlier detection, primarily through mining of routinely-collected data from electronic healthcare records (EHR). This paper provides an overview of ongoing initiatives exploring data from EHR for signal detection vis-à-vis established spontaneous reporting systems (SRS). We describe the role SRS has played in regulatory decision making with respect to safety issues, and evaluate the potential added value of EHR-based signal detection systems to the current practice of drug surveillance. Safety signal detection is both an iterative and dynamic process. It is in the best interest of public health to integrate and understand evidence from all possibly relevant information sources on drug safety. Proper evaluation and communication of potential signals identified remains an imperative and should accompany any signal detection activity.