Rationalising antibiotic use
To mark this week’s EU Antibiotic Awareness Day, Dr Alastair Hay offers GPs practical pointers on how to safely and effectively minimise antibiotic prescribing
To mark this week's EU Antibiotic Awareness Day, Dr Alastair Hay offers GPs practical pointers on how to safely and effectively minimise antibiotic prescribing
There are lots of reasons why we prescribe antibiotics. We don't want our patients to experience complications and are uncertain which patients will benefit. In the face of rising patient expectations, we don't like to dissatisfy them and there is the constant pressure of time. Many of us want to minimise our antibiotic prescribing, but how?
When antibiotics were first developed at the end of the Second World War, they were literally life-saving. It is not surprising that they developed a mythical status in the mind of the public. Since then they have been used for decreasingly severe infections. Demand for treatment is especially high when patients are stressed and wanting to sleep or perform well during the day.
Necessary versus discretionary
For a number of acute and chronic conditions managed in primary care, antibiotics are usually regarded as necessary. These include pneumonia, pyelonephritis, acute UTI, STIs, cellulitis and post-splenectomy.
But for other infections – including acute otitis media, sore throat, the common cold, acute sinusitis and acute bronchitis – the risks and benefits are much more open to interpretation as illustrated by the twofold to threefold variation in the use of antibiotics for these conditions between clinicians1, practices2 and countries3.
For all these respiratory tract infections (RTIs), the benefit of antibiotics for the average patient is minimal in terms of symptom relief and reducing illness duration4, 5, 6, 7, 8.
The variations in antibiotic use are also associated with variations in antimicrobial resistance rates between and within countries. Bacteria are becoming resistant to antibiotics faster than the pharmaceutical industry is developing new ones. So every time we use an antibiotic, we ‘use up' a little of its future value for the wider population9.
The means by which antibiotics promote resistance are complex, but include two important mechanisms.
First, they kill susceptible commensal bacteria which, through competition, usually prevent the overgrowth of the small number of endogenous resistant bacteria we all host. These resistant bacteria are also often commensal and may appear harmless. But two problems arise. These bacteria may be passed to other people in close contact, who are particularly vulnerable if they too have received an antibiotic which has killed their susceptible bacteria.
Of more concern is the fact that commensal bacteria can become pathogenic and cause symptomatic infection. So a single course of antibiotics may lead to the presence of resistant bacteria in two groups, our index patient and their wider contacts. Even when a patient has no resistant endogenous bacteria, eradicating the susceptible bacteria can leave them vulnerable to the subsequent colonisation of resistant bacteria from other people.
The second mechanism by which bacteria become resistant is by passing resistance between each other in the form of genes and plasmids (extra-chromosomal DNA molecules). There are repeated opportunities for commensal organisms to acquire these since they are present in the body for prolonged periods.
Minimising antibiotic use
These tips aim to help cut the use of antibiotics for situations in which their use is usually regarded as discretionary.
• Ask patients if they are expecting an antibiotic. Studies have repeatedly shown that for adults10, 11 and children12, patients who state prior to the consultation that they expect an antibiotic are more likely to receive a prescription, even when the clinician does not think it is warranted. Studies have also shown that clinicians do not accurately guess which patients expect an antibiotic. Clarifying expectations will allow you to discuss the advantages and disadvantages of antibiotic use and is likely to improve doctor and patient satisfaction.
• Reassure the patient that RTIs are a normal part of life. The average person experiences four to six infections a year. This is higher (six to eight) in children.
• Tell the patient about the natural history of their condition. Setting realistic expectations is likely to reduce subsequent unnecessary consultations. Recent NICE guidelines for prescribing antibiotics for self-limiting RTIs in adults and children in primary care13 suggest patients should be advised that on average acute otitis media lasts four days, sore throat seven days, common cold 10 days, sinusitis 18 days and acute bronchitis 21 days.
• Many patients simply want to know if there is anything more they can do to relieve symptoms. Advise them to rest, take plenty of fluids and to use paracetamol and/or ibuprofen for their antipyretic analgesic properties. Explaining that they are ‘doing all the right things', especially if parents, can be very reassuring. You may need to challenge misconceptions that antibiotics were responsible for the relief experienced in previous infections.
• Give the patient a leaflet. Leaflets that explain the natural history and protective role of symptoms – for example cough in clearing unwanted phlegm – have been shown to reduce antibiotic consumption. Go to www.patient.co.uk for patient information.
• Discuss the advantages of prescribing. For most patients with RTIs, there are few, if any, clinically meaningful advantages to prescribing. For example, symptom duration is rarely reduced by more than a few hours.
The recent NICE guidance identifies a number of important exceptions. It advises we give an immediate prescription to:
– patients who are systemically very unwell
– children under two with bilateral acute otitis media
– children with acute otitis media and otorrhoea
– patients with sore throat with three or more Centor criteria (a history of fever, tonsillar exudate, tender anterior cervical lymphadenopathy and the absence of cough)
– patients with symptoms or signs suggestive of serious illness or complications
– patients at high risk of complications because of pre-existing heart, lung, liver or neuromuscular disease, immunosuppression or cystic fibrosis
– young children who were born prematurely.
We should also treat patients over 65 with acute cough with two or more of the following: hospitalisation in the past 12 months, diabetes, congestive cardiac failure or current use of steroids. Patients over 80 with acute cough should be treated if they have one or more of these criteria.
• Discuss the disadvantages of prescribing. These are:
– side-effects, such as diarrhoea, vomiting, rash
– serious adverse effects, which are rare but can be fatal and include anaphylaxis, Clostridium difficile infection, Stevens Johnson syndrome and hepatitis
– combined oral contraceptive pill failure
– encouraging the patient to believe antibiotics are necessary for similar symptoms in the future (this has been shown to increase future workload)
– antibiotic resistance.
Increasing numbers of studies are demonstrating direct links between antibiotics prescribed in primary care
and the subsequent development of bacterial resistance in patients in primary care14, 15, 16, 17.
• Consider a delayed prescription. This is a good ‘get out of jail free' card if you feel a battle coming on. Delayed antibiotic prescribing has been shown to be safe and as effective – or ineffective – as an immediate prescription in a range of conditions including acute otitis media, sore throat, acute bronchitis and conjunctivitis. Advise the patient to take an antibiotic only if their condition is worsening and be careful not to advise use ‘in a couple of days if no better' as most patients will not be better within this time. Patients are less likely to cash the prescription if they are given written information about their symptoms; especially their natural history and protective roles, for example cough. Compared with an immediate prescription, delayed prescribing can reduce antibiotic consumption by two-thirds and does not reduce patient satisfaction compared with not prescribing.
• If prescribing, offer the shortest course possible and use a narrow spectrum antibiotic. Evidence shows that the degree of antibiotic resistance increases with every milligram of antibiotic taken15 so courses should be the minimum necessary to treat the infection. Broad-spectrum antibiotics such as cephalosporins and quinolones are active against a broad range of gram-positive and negative bacteria. They will therefore kill a broad range of ‘healthy' bacteria, leaving space for resistant bacteria to colonise or cause infection. The vast majority of RTIs can be managed with narrow-spectrum antibiotics such as penicillin, amoxicillin or erythromycin.
• Offer a review if the underlying condition is worsening. This will reassure many patients that you are taking their symptoms seriously. Advice should include the conditions under which patients should reconsult, for example increasing breathlessness in a child with cough.
• A two- to four-day course of oral antibiotics appears to be as effective as seven to 14 days in eradicating lower UTI in children18. Short courses are as effective as longer courses for women with uncomplicated UTI19, 20.
• Avoid talking about ‘bacteria and viruses'. Research has shown that for many patients, these discussions are confusing and counterproductive, leaving them feeling less reassured. It's better to focus on agreeing that the patient has an infection but that research indicates they rarely respond to antibiotic treatment and it is better to focus on other symptomatic measures. Many patients simply want more information abut their illness and its natural history.
• Avoid talking about antibiotic resistance unless you have time to explain it. Research shows that patients do not understand the concept of resistance and generally do not feel they can influence the problem. They think the solution is for scientists to develop new antibiotics and hospitals to clean up .
• Children are an important potential target group for delayed prescribing as they are frequent attenders. Parents may be more concerned to avoid antibiotics in children than themselves. But clinical uncertainty is greater in the very young (and old).
• Patients at risk of endocarditis should receive prompt treatment for infections. But NICE does not recommend prophylaxis for patients undergoing dental or other procedures of the upper and lower GI tract, GU tract, upper and lower respiratory tract or ear, nose and throat21.
Dr Alastair Hay is a GP in Bristol and consultant senior lecturer in the academic unit of primary care at the University of Bristol. He runs a programme of research in the management of common infections and antibiotic resistance in primary care
Competing interests: None declaredMost RTIs can managed using a narrow-spectrum antibiotic like amoxicillin Most RTIs can managed using a narrow-spectrum antibiotic like amoxicillin