Let me clear my throat: empiric antibiotics in respiratory tract infections

Alexander John Langley, MD MS MPH

Goals of this talk

Overuse of antibiotics is a major issue, as a result many specialist medical groups have developed guidelines over the past 20 years to curb unnecessary empiric antibiotics

Many talks focus on when not to prescribe antibiotics, particularly in the outpatient setting

This talk is aimed at helping providers feel more comfortable in choosing antibiotics in the outpatient setting when data collection and follow up are more difficult than the inpatient setting, but where appropriate treatment may help to avoid expensive ED and inpatient care

Outline

There are many potential topics, we shall cover three outpatient topics

Cough – and the clinical diagnosis of pneumonia

Nasal congestion – and the clinical diagnosis of bacterial sinusitis

Sore throat – and the clinical diagnosis of strept throat

What we will not cover

Special populations – kids, pregnant women, diabetics, immunocompromised, geriatric

Other settings – ED, inpatient, ICU, nursing home

Cough and Pneumonia

Why do we want to treat: dual goals of symptom relief, and preventing serious invasive disease including possible death

Why is it hard to treat: most where a pathogen can be isolated are viral, most commonly rhinovirus. Followed by influenza (not topic of today’s topic), and third is Strep Pneumo – representing 5% of cases (and 37% of bacterial cases)

Making the diagnosis

There are two roles for the MD – does someone have pneumonia and need antibiotics, does someone need hospitalization Diagnosis – Heckerling decision tool on the previous page can help, IDSA

guidelines say diagnosis should include CXR (2 view) as part of standard part of assessment

CURB 65 and CRB 65 – used for triaging – 0 or 1 can be safely managed outpatient, >=3 should be hospitalized

Treatment

Mild with no recent antibiotics – choose a macrolide or doxycycline. 5 day treatment is as effective as longer courses

If recent antibiotics or comorbidities – use a different class than previously used, preferred for either is respiratory fluoroquinolone – either levofloxacin or moxifloxacin

Resistance to azithromycin in mycoplasma varies from 7% in Seattle to 50% in New Jersey

Resistance to azithromycin in Strep Pneumoniae can reach 60% (currently 9% in all Swedish inpatients)

Nasal Congestion and bacterial sinusitis

Why do we treat – mostly symptom relief, although invasive disease can occur

Why is it hard to treat – Cannot initially differentiate from viral processFortunately can usually delay treatment without significant risk of

severe complications

Making the diagnosis

After 10 days of symptoms without improvement the probability of bacterial infection rises to 60%

There is also the concept of double sickening – primary viral infection starts getting better, than a secondary bacterial infection causes distinct worsening of symptoms after this improvement

Diagnosis –IDSA 2 major, or 1 major and 2 minor with symptoms Major - purulent nasal discharge, nasal congestion or obstruction, facial congestion or fullness,

facial pain or pressure, decreased sense of smell, fever

Minor - headache, ear pain, pressure, fullness; halitosis, dental pain; cough, fatigue

Treatment

70% of patients with bacterial rhinosinusitis resolved their infection within 2 weeks without antibiotics. Antibiotics do shorten symptoms – but main benefit is only seen in patients with symptoms persisting beyond 15 days

As a result watchful waiting is recommended for those presenting within 7 days regardless of severity (according to the 2015 AAO-HNS)

Antibiotic choice is amoxicillin or amoxicillin-clavunate (if risk of resistance) for 5-10 days

Intranasal steroids provide modest benefit in combination with antibiotics

Sore throat – group A strep

Why do we treat: primarily to prevent rheumatic heart disease, some mild relief of symptoms

Does not prevent PANDAs or post streptococcal glomerulonephritis

Why its hard to diagnosis– even at it’s most prevalent (in November) it only represents 5-15% of pharyngitis, with mononucleosis a common culprit

Diagnosis

Modified Centor score1 Point for each of the following- Age (ranges from +1 to -1)- tender anterior cervical lymphadenopathy- Tonsillar exudates- Fever- No cough

Get a rapid strep for scores of 3-4Culture no longer recommended routinely in adults,Unless patient is re-presenting after an initial evaluation

Treatment

Penicillin or amoxicillin

If penicillin allergic -> cephalosporins, clindamycin, macrolide

Only 66% of group A strep is sensitive to clindamycin at uw

If there is a recurrence broaden amoxicillin to augmentin, Keflex to Cefdinir. If due to non-compliance than give penicillin G benzathine

Take home points

Antibiotic usage is difficult to determine because of symptomatic overlap with viral infections

Using constellations of symptoms can help you determine patients with reasonably high likelihood of bacterial infections – but getting this likelihood to 100% is difficult or even impossible with even the most robust work up

Delayed treatment in selected patients is an effective way to safely manage a variety of infections while reducing antibiotic use

Thank you

Y’all the best