Lecture 4.2 - Antimicrobial resistance and stewardship.pdf

How antibiotic resistance happens: Definitions: ◦MDR (multi-drug resistant) - non-susceptibility to at least one agent in three or more antimicrobial categories. ◦XDR (extensively drug resistant) - non-susceptibility to at least one agent in all but two or fewer antimicrobial categori...

How antibiotic resistance happens: Definitions: ◦MDR (multi-drug resistant) - non-susceptibility to at least one agent in three or more antimicrobial categories. ◦XDR (extensively drug resistant) - non-susceptibility to at least one agent in all but two or fewer antimicrobial categories. ◦PDR (pan-drug resistant) - non-susceptibility to all agents in all antimicrobial categories Use of antibiotics results in resistance: ◦Does this apply to prescribed antibiotics? ◦Antibiotic stewardship depends on the casual relationship: ‣ Antimicrobial use ------> resistance Evidence that antimicrobials cause resistance: ◦Laboratory evidence ‣ Provides biological plausibility ◦Ecological studies ‣ Relates levels of antibacterial use in a population with levels of resistance ◦Individual level data ‣ Relates prior antibacterial use in an individual with the subsequent presence of bacterial resistance (detected by culture or molecular means) Ecological studies: ◦Relationship between prior antimicrobial use and resistance in Streptococcus pneumoniae in Finland, 1997-2002 ‣ Regional rates of consumption of penicillins, cephalosporins and macrolides estimated from sales figures ‣ S pneumoniae penicillin and macrolide resistance data collected from 26 labs nationally ‣ Previous year antibacterial use compared with resistance rates ‣ Macrolide and azithromycin use were associated with increased macrolide resistance on a regional level. ‣ Beta-lactam and cephalosporin use associated with increased rates of low-level penicillin resistance. ‣ High-level use of penicillins was not connected to increased rates of low-level penicillin resistance Individual level data: ◦Systematic review and meta-analysis of relationship between prior antibacterial exposure and resistance in individual patients in primary care. ‣ 24 studies reviewed ‣ Antibiotics prescribed in community for urinary tract infections are linked with increased rates of carriage of resistant bacteria in recipient patients for up to 12 months ‣ Longer durations and multiple courses associated with higher resistance rates  Spread of NDM: IDSA definition of antimicrobial stewardship: ◦Coordinated interventions designed to improve and measure the appropriate use of antimicrobials by promoting the selection of the optimal antimicrobial drug regimen, dose, duration of therapy, and route of administration. Antimicrobial stewards seek to achieve optimal clinical outcomes related to antimicrobial use, minimise toxicity and other adverse events, reduce the costs of health care for infections, and limit the selection for antimicrobial resistant strains. Antimicrobial stewardship: ◦Up to half of antibiotic use in humans and much of antibiotic use in animals is unnecessary and inappropriate ◦Stopping even some of the inappropriate and unnecessary use of antibiotics in people and animals would help greatly in slowing down the spread of resistant bacteria. ◦This commitment to always use antibiotics appropriately and safely—only when they are needed to treat disease, and to choose the right antibiotics and to administer them in the right way in every case—is known as antibiotic stewardship. ◦In the UK, 80% percent of antibiotic prescribing occurs in the community. UK prescribing: ◦80% of antibiotics are prescribed in general practice. Why do GPs prescribe antimicrobials: ◦Relief of symptoms ◦Worry about complications/more serious illness ◦Patient pressure Symptom benefit from antibiotics: Elements of stewardship programme: ◦MDT ◦Surveillance ‣ Process measures Antibacterial use (quantity, type, appropriateness) Benchmarking within and between organisations  ‣ Outcome measures Patient Emergency of resistant organisms ◦Interventions: ‣ Persuasive ‣ Restrictive ‣ Structural Stewardship intervention types: Evidence of effectiveness of stewardship: Clinical scenario - acute sore throat: What is the evidence for back-up/delayed prescribing:  The patient perspective: Percentage of the public in favour of delayed antibiotic prescriptions: TARGET: ◦Treat Antibiotics Responsibly Guidance, Education and Tools booklet Discussing antibiotics with patients: ◦Patients are likely to better understand and accept a back-up/delayed antibiotic prescription if you discuss two key points: ‣ 1. Reasons for giving it: It can be helpful to: Provide reassurance that there is no need for an immediate antibiotic prescription and, if given, the patient is more likely to experience the side effects of antibiotics rather than the benefits; Although the illness is likely to be self-limiting, acknowledge that it is not possible to predict exactly how the illness will progress; And that you would like the patient to have access to antibiotics should their symptoms get worse or not improve as expected. ‣ 2. Specific number of days to wait For example: "wait another 2 days and start the antibiotic if you are not feeling any better by then". It is important to be specific as your patient may worry about waiting too long if they are not confident about when to start the antibiotics. Your advice should be tailored to the patient’s current experience of the infection, the prior duration and expected natural history, their co-morbidities, and their ability to access antibiotics in a timely manner. The TARGET patient information leaflets can help with this. These can be incorporated in the last four techniques in CHESTSSS (Timeline, Shortcomings, Self-care, Safety-netting). Five ways to issue a back-up/delayed antibiotic prescription: ◦The format you use to give a back-up/delayed antibiotic prescription to a patient makes little difference to antibiotic use - as long as you give clear advice to patients. ‣ 1. Give a prescription with advice to get it dispensed if needed ‣ 2. Ask the patient to collect prescription from an agreed location (e.g. the reception or pharmacy if using electronic prescription transfer) ‣ 3. Write a post-dated prescription ‣ 4. Ask the patient to contact the practice again to obtain a prescription ‣ 5. Ask the patient to collect the antibiotic now but only use it if needed  Remember local guidelines: ◦Guidelines reflect local resistance data: ‣ Hospitals ‣ GPs