Primary Care Corner with Geoffrey Modest MD: Antibiotic Overprescribing and Acute Respiratory Infections
22 Jan, 16 | by EBM
By Dr. Geoffrey Modest
In my never-ending pursuit of protecting the microbiome, and also decreasing further development of antibiotic resistance, there was a helpful clinical guideline from the American College of Physicians and the CDC (see doi:10.7326/M15-1840). Nothing new here, but it really reinforces both the remarkable overuse of anti-bacterial antibiotics for nonbacterial conditions and the very common conditions when this is happening (the lowest-hanging fruits), which if implemented should decrease bacterial resistance, decrease antibiotic-associated adverse events including lots of deaths, and save lots of money (and the microbiome).
- Antibiotics are prescribed in >100M adult ambulatory care visits in the US/yr, with cost of $10.7 b(as in, billion) in 2009, with $6.5 b in the community setting
- 41% of prescriptions are for respiratory conditions
- There are >2M antibiotic-resistant illnesses and 23K deaths in US/yr, with cost of $30 b
- Higher rates of multi-drug resistant pneumococcal disease occur in places where there is more prescribing of broad-spectrum antibiotics, esp extended-spectrum cephalosporins and macrolides
- And, antibiotics as a group are responsible for the largest number of medication-related adverse events, including 20% of ER visits for adverse drug reactions
- Adverse drug reactions range from mild to serious: an estimated 5-25% of patients on antibiotics have adverse events, and 1 in 1000 have a serious one. E.g.: c difficile causes 500K infections and 29,300 deaths/year in the US, with an estimated $1 billion in extra medical costs
- An estimated 50% of outpatient antibiotics are considered unnecessary, with a direct cost of $3 b
- Although (the good news) antibiotic prescriptions have decreased 18% in people>5 yo in the past decade, (the bad news) prescriptions for broad-spectrum fluoroquinolones and macrolides have increased >4-fold
- Acute uncomplicated bronchitis (self-limited inflammation of bronchi with cough, which may or may not be productive), lasting up to 6 weeks.
- Has 100M outpatient visits/yr (10%!! of total), and >70% result in antibiotic prescription!! — the largest cause of inappropriate antibiotic prescriptions
- Need to differentiate from pneumonia (in adults <70 yo, pneumonia unlikely in absence of all of: tachycardia with HR>100, tachypnea with RR>24, fever with T>38C, and abnormal findings on chest exam (rales, egophony, or tactile fremitus)
- Meta-analysis of 15 RCTs found limited benefit of antibiotics but a trend to increased adverse events. and no clear decrease in days to cough resolution
- There may be benefit from cough suppressants (dextromethorphan or codeine), expectorants (guaifenesin), first-generation antihistamines (diphenhydramine), decongestants (phenylephrine), b-agonists (albuterol), though data to support specific therapies are limited and b-agonists don’t seem to help unless there is underlying asthma or COPD [by the way, I think there are lots of scripts for the more selective antihistamines, such as loratadine, which have limited effectiveness for viral infections]
- There are some cases of antibiotic-sensitive causes (mycoplasma, chlamydia, B pertussis), though these are uncommon and should be considered in cases where transmission in the community is reported [no comment here that it is hard to know of transmission in the community if these are not tested for….., but in broad strokes, treating people indiscriminately with antibiotics does not seem to help]
- So, do not perform testing or give antibiotics in patients with bronchitis unless pneumonia is suspected
- Pharyngitis (benign self-limited illness with sore throat, worse when swallowing, with or without constitutional symptoms
- 12M outpatient visits/yr (1-2% of total). 60% get antibiotics
- No further testing indicated if likely viral: associated symptoms of cough, nasal congestion, conjunctivitis, hoarseness, diarrhea, oropharyngeal ulcers/vesicles
- Those with symptoms suggestive of strep should get rapid strep test, throat culture or both: e.g. symptoms of persistent fever, rigors, night sweats, tender lymph nodes, tonsillopharyngeal exudates, scarlatiniform rash, palatal petechiae, and swollen tonsils.
- The Centor criteria are often used (fever, tonsillar exudates, tender anterior cervical nodes, absence of cough), BUT because the positive predictive value for group A strep is so low, the IDSA (Infectious Diseases Society of America) only suggests using these as a means to do no further testing or prescribing antibiotics if there are <3 criteria.
- Some patients present with severe signs/symptoms, such as difficulty swallowing, drooling, neck tenderness or swelling, and should be evaluated for peritonsillar abscess, parapharyngeal abscess, epiglottitis, Lemierre syndrome
- If strep found on testing, then treat with appropriate narrow-spectrum antibiotics, which decreases duration of sore throat by 1-2 days, but may also decrease risk of acute rheumatic fever (more common in kids and teens), peritonsillar abscess, and spreading the infection.
- No need to treat asymptomatic carriers of strep, since low likelihood of spreading it and low potential for complications
- Not do tonsillectomy in adults just to reduce frequency of recurrent strep infections
- Treat adults with analgesics (aspirin, acetaminophen, NSAIDs), throat lozenges. Little data on salt water, viscous lidocaine [or, I would add, tea with honey or lemon, as is preferred by many of my patients]
- So, test patients with symptoms suggestive of Group A strep pharyngitis, and treat only if confirmed strep [and use narrow-spectrum antibiotics, my addition]
- Acute rhinosinusitis (self-limited viral infection, allergy, or irritant which causes inflammation in nasal or paranasal sinus cavity. Lasts 1-33 days with most resolving in a week. Can be associated with nasal congestion, purulent discharge, maxillary tooth pain, facial pain/pressure, fever, cough, hyposmia/anosmia, ear pressure, headache, hallitosis.
- >4.3 M adults have diagnosis annually, >80% get antibiotics, mostly macrolides, and most unnecessarily so
- No role for radiologic imaging — does not reliably differentiate bacterial from viral causes
- Bacterial cause more likely if symptoms persist >10 days without improvement, symptoms are severe (fever >39C, purulent nasal discharge, or facial pain >3 days), or if new onset fever, headache, increased nasal discharge after a viral URI was improving
- If treating, preferred agent per IDSA is amoxacillin-clavulanate,with doxycycline or respiratory fluoroquinolone as alternative; the Am Acad of Otolaryngology emphasizes initial management of watchful waiting regardless of symptom severity; some medical societies recommend amoxacillin (no direct evidence that amoxacillin-clavulanate is clinically superior). In fact rhinosinusitis is usually self-limited even if caused by bacteria. A meta-analysis found that the number-needed-to-treat was 18 for 1 patient to have a more rapid cure, but the number-needed-to-harmfrom adverse antibiotic effects was 8
- Nasal saline irrigation and intranasal steroids may alleviate symptoms and decrease likelihood of antibiotic use. Other supportive therapies include analgesics for pain, systemic or topical decongestants, mucolytics, and antihistamines
- So, reserve antibiotics unless patient has persistent symptoms >10 days, onset of severe symptoms/signs of fever > 39C and purulent nasal discharge or facial pain for >3 consecutive days, or worsening of symptoms after a viral illness that lasted >5 days and was initially improving
- 37 M ambulatory care visits (3%), 30% get antibiotics
- Complications include acute bacterial sinusitis, asthma exacerbation, and otitis media. Antibiotics play NO ROLE in preventing these.
- Best means to prevent transmission: handwashing
- Symptomatic therapy, though advise patient that symptoms can last 2 weeks. antihistamine-analgesic-decongestants work. Zinc supplements help if given within 24 hours. no evidence for vitamins/herbal remedies
- So, do not prescribe antibiotics for patients with the common cold
As many of you know, I have sent out many blogs on this. In particular:
http://blogs.bmj.com/ebm/2014/07/11/primary-care-corner-with-geoffrey-modest-md-whos-remarkable-scary-report/ highlights the worldwide emergence of antibiotic-resistant bugs
http://blogs.bmj.com/ebm/category/antimicrobial-resistance/ includes a slew of blogs on antimicrobial resistance, including long-term changes in the gut microbiome after even a single dose of antibiotics, importance of antibiotic use in food industry in creating very threatening changes in microbial sensitivity, effects of international travel on changes in microbial sensitivities in the gut microbiome, and the real importance of using the narrowest-spectrum antibiotics in treating pneumonia/strep pharyngitis
So, I do realize that it can be difficult to dissuade some patients from getting antibiotics. I frequently hear “but my (cough, bronchitis, cold…) is bad and in the past whenever I get antibiotics it goes away right away”. Though, I have noted over the years that fewer patients are so insistent (perhaps relating to my sense that it is the dying breed of older patients who are more insistent than younger ones). In any event, I have had some success in stating over-enthusiastically that “the good news is that you do not have a bacterial infection, do not need antibiotics, but I can give you some medicines to help relieve the symptoms.” Or, if pushed, “antibiotics really don’t help this type of infection, which gets better on its own. And there is a very real chance you could get a very serious side-effect. So I really think it is important not to take antibiotics”. And in my experience (perhaps augmented by my gray hair), these are usually successful and lead to a satisfying encounter, without antibiotics being prescribed.