Objective To characterise failure of antibiotic treatment in primary care in the United Kingdom in four common infection classes from 1991 to 2012.Design Longitudinal analysis of failure rates for first line antibiotic monotherapies associated with diagnoses for upper and lower respiratory tract infections, skin and soft tissue infections, and acute otitis media. Setting Routine primary care data from the UK Clinical Practice Research Datalink (CPRD).Main outcome measures Adjusted rates of treatment failure defined by standardised criteria and indexed to year 1 (1991=100).Results From 58 million antibiotic prescriptions in CPRD, we analysed 10 967 607 monotherapy episodes for the four indications: 4 236 574 (38.6%) for upper respiratory tract infections; 3 148 947 (28.7%) for lower respiratory tract infections; 2 568 230 (23.4%) for skin and soft tissue infections; and 1 013 856 (9.2%) for acute otitis media. In 1991, the overall failure rate was 13.9% (12.0% for upper respiratory tract infections; 16.9% for lower respiratory tract infections; 12.8% for skin and soft tissue infections; and 13.9% for acute otitis media). By 2012, the overall failure rate was 15.4%, representing an increase of 12% compared with 1991 (adjusted value indexed to first year (1991) 112, 95% confidence interval 112 to 113). The highest rate was seen in lower respiratory tract infections (135, 134 to 136). While failure rates were below 20% for most commonly prescribed antibiotics (amoxicillin, phenoxymethylpenicillin (penicillin-V), and flucloxacillin), notable increases were seen for trimethoprim in the treatment of upper respiratory tract infections (from 29.2% in 1991-95 to 70.1% in 2008-12) and for ciprofloxacin (from 22.3% in 1991-95 to 30.8% in 2008-12) and cefalexin (from 22.0% in 1991-95 to 30.8% in 2008-12) in the treatment of lower respiratory tract infections. Failure rates for broad spectrum penicillins, macrolides, and flucloxacillin remained largely stable.Conclusions From 1991 to 2012, more than one in 10 first line antibiotic monotherapies for the selected infections were associated with treatment failure. Overall failure rates increased by 12% over this period, with most of the increase occurring in more recent years, when antibiotic prescribing in primary care plateaued and then increased.

Background-Blocking the tubuloglomerular feedback mechanism with adenosine A1 receptor antagonists seems to improve diuresis and sodium excretion without compromising the glomerular filtration rate in patients with heart failure. However, the direct cardiac effects of this compound class have not been investigated to date. Methods and Results-In total, 111 patients (109 men and 2 women) received a 1-hour infusion of 5, 10, and 15 mg SLV320, an adenosine A1 receptor antagonist, placebo, or 40 mg furosemide. Mean age was 57.9 years, mean ejection fraction was 28.1%, 82 patients were of New York Heart Association class II, and 29 patients were of New York Heart Association class III. Hemodynamic parameters (heart rate, blood pressure, pulmonary capillary wedge pressure, mean pulmonary arterial pressure, systemic vascular resistance, right atrial pressure, and cardiac output) were determined. Kidney function was assessed by cystatin C measurements and by analysis of urine output and urine electrolytes. In addition, pharmacokinetics of SLV320 and ex vivo inhibition of adenosine A1 receptor activity were performed. SLV320 was well tolerated, and no serious adverse events were observed. Heart rate, blood pressure, pulmonary capillary wedge pressure, mean pulmonary arterial pressure, right atrial pressure, and cardiac output were not altered by any dose of SLV320. Pulmonary capillary wedge pressure was significantly (Pϭ0.04) decreased by furosemide (Ϫ6.2Ϯ5.9 mm Hg). Systemic vascular resistance was significantly (Pϭ0.04) increased in the furosemide group (ϩ166.70Ϯ261.87 dynes ⅐ s Ϫ1 ⅐ cm

ObjectiveTo determine whether treatment with clarithromycin for respiratory tract infections was associated with an increased risk of cardiovascular (CV) events, arrhythmias or all-cause mortality compared with other antibiotics.DesignRetrospective cohort design comparing clarithromycin monotherapy for lower (LRTI) or upper respiratory tract infection (URTI) with other antibiotic monotherapies for the same indication.SettingRoutine primary care data from the UK Clinical Practice Research Datalink and inpatient data from the Hospital Episode Statistics (HES).ParticipantsPatients aged ≥35 years prescribed antibiotic monotherapy for LRTI or URTI 1998–2012 and eligible for data linkage to HES.Main outcome measuresThe main outcome measures were: adjusted risk of first-ever CV event, within 37 days of initiation, in commonly prescribed antibiotics compared with clarithromycin. Secondarily, adjusted 37-day risks of first-ever arrhythmia and all-cause mortality.ResultsOf 700 689 treatments for LRTI and eligible for the CV analysis, there were 2071 CV events (unadjusted event rate: 29.6 per 10 000 treatments). Of 691 998 eligible treatments for URTI, there were 688 CV events (9.9 per 10 000 treatments). In LRTI and URTI, there were no significant differences in CV risk between clarithromycin and all other antibiotics combined: OR=1.00 (95% CI 0.82 to 1.22) and 0.82 (0.54 to 1.25), respectively. Adjusted CV risk in LRTI versus clarithromycin ranged from OR=1.42 (cefalexin; 95% CI 1.08 to 1.86) to 0.92 (doxycycline; 0.64 to 1.32); in URTI, from 1.17 (co-amoxiclav; 0.68 to 2.01) to 0.67 (erythromycin; 0.40 to 1.11). Adjusted mortality risk versus clarithromycin in LRTI ranged from 0.42 to 1.32; in URTI, from 0.75 to 1.43. For arrhythmia, adjusted risks in LRTI ranged from 0.68 to 1.05; in URTI, from 0.70 to 1.22.ConclusionsCV events were more likely after LRTI than after URTI. When analysed by specific indication, CV risk associated with clarithromycin was no different to other antibiotics.

Purpose The purpose of this study was to evaluate the effectiveness of the risk minimisation measures (RMMs) implemented in Europe in 2014 for valproate‐containing products to mitigate their risk during pregnancy and to characterise valproate prescribing patterns in women of childbearing potential (WCBP) before and after implementation of RMMs. Methods A multinational cohort study based on existing data sources using a pre‐/post‐ design was performed in five European countries (France, Germany, Spain, Sweden, UK) in an outpatient setting. Effectiveness of RMMs was assessed by comparing the proportion of valproate initiations as second (or subsequent) line therapy before and after implementation of RMMs (primary outcome) with an increase in this proportion indicating success of RMMs. Overall use of valproate and incidence of pregnancies in WCBP were also examined. Results The proportion of valproate initiations as second line therapy increased after implementation of RMMs in incident female users in Sweden (from 81.1%, 95% CI 79.9%‐82.3% to 84.5%, 95% CI 83.5%‐85.5%) and the UK (from 66.4%, 95% CI 64.5%‐68.3% to 72.4%, 95% CI 70.0%‐74.9%), it remained the same in Germany and Spain and decreased in France from 48.7% (95% CI 45.6%‐51.9%) to 40.6% (95% CI 37.6%‐43.7%). In Sweden and the UK, the incidence of pregnancies exposed to valproate decreased in the post‐implementation period: 8.0 vs 9.5 and 10.9 vs 16.9 per 1000 person‐years, respectively. Conclusion The results on primary outcome of this study suggest limited effectiveness of the RMMs. Additional RMMs were implemented in 2018.