Treatment of Respiratory Infections

Treatment of Respiratory Infections

• Respiratory infections are frequently treated with antibiotics.
• Antibiotics are categorized as typical or atypical.
• Understanding antibiotic pharmacokinetics and mechanisms of action is crucial.
• Common adverse effects vary by antibiotic class.
• Precautions, contraindications, and potential drug interactions of antibiotics need careful consideration.
• Alternative antibiotics are often considered if patients experience resistance or allergies.

Upper Respiratory Tract Infections (URTI)

• URTIs are typically caused by viruses, with bacterial causes less common (~2%).
• Common bacterial URTIs include sinusitis, pharyngitis, tonsillitis, epiglottitis, laryngitis, and acute otitis media.
• The most common bacterial causes of URTIs generally include Streptococcus pyogenes (Group A strep), Streptococcus pneumoniae, Haemophilus influenzae, viridans streptococci, and Moraxella catarrhalis.
• Streptococcus pyogenes can lead to rheumatic fever.

Acute Sinusitis/Otitis Media Treatment

• High-dose amoxicillin (oral, 8-12 hourly, 5-10 days), co-amoxiclav (oral, 8-12 hourly, 5-10 days) are common initial treatments.
• Macrolide/azalide antibiotics (such as erythromycin or azithromycin) may be used if there's a penicillin allergy.

Chronic Sinusitis Treatment

• Antibiotic treatment for chronic sinusitis isn't always successful.
• Group A β-hemolytic streptococci (e.g., S. pyogenes) may require IM benzathine benzylpenicillin or oral phenoxymethylpenicillin (10-12 days).
• Oral amoxicillin or co-amoxiclav (10 days) is also an option, however, avoid if Epstein Barr virus infection is suspected.
• Macrolides/azalides like clarithromycin or azithromycin (oral, 3 days) are alternatives in case of penicillin allergy.

Epiglottitis Treatment

• Haemophilus influenzae is commonly associated with this condition.
• Three generations of cephalosporin (ceftriaxone by IM injection, cefotaxime)are typically followed by co-amoxiclav (10 days).
• Azithromycin/Erythromycin (3 days) is considered in case of penicillin allergy

Conjunctivitis Treatment

• Purulent conjunctivitis can be treated with topical chloramphenicol ointment (5–7 days).
• Other topical treatments that may be used include tobramycin, ciprofloxacin, fusidic acid, or bacitracin/polymyxin B ointment.
• Neonatal conjunctivitis (caused by N. gonorrhoeae) requires saline irrigation of the eyes and 3rd-generation cephalosporin ceftriaxone (IM, single dose) and if symptoms develop 24 hours after birth, IM ceftriaxone + oral azithromycin (single dose)
• Inclusion conjunctivitis/trachoma (C. trachomatis) is treated using macrolide/doxycycline

Lower Respiratory Tract Infections

• Types include acute bacterial bronchitis and bacterial pneumonia.
• Acute bacterial bronchitis is an inflammation of the airways frequently following a viral infection.
• It usually resolves without medical intervention.
• Bacterial pneumonia involves infection in the lungs (filling alveoli with pus and fluid).
• It requires treatment with antibiotics.

Acute Bacterial Bronchitis Treatment

• Antibiotics are not typically necessary unless underlying COPD is present.
• In cases of COPD exacerbation with S. pneumoniae or H. influenzae, amoxicillin (oral, 8 hourly, 5 days), doxycycline (oral, 12 hourly, 5 days), or newer fluoroquinolones (e.g., moxifloxacin/levofloxacin) may be prescribed.

Bacterial Pneumonia Treatment (Community Acquired)

• General: Rest, fluids and oral antibiotics
• Specific treatment:
• Patients under 65 with no co-morbidities: Amoxicillin (high dose) for 5 days, if ineffective a macrolide/azalide may be added .
• Patients aged 65 or over or with co-morbidities: Co-amoxiclav (oral 12 hourly 5 days), 2nd/3rd Cefuroxime or Ceftriaxone or Cefotaxime .
• Penicillin allergy: Gemifloxacin or moxifloxacin (oral, 5 days)
• Atypical pneumonia: Macrolide (azithromycin), or gemifloxacin, moxifloxacin.
• P. jirovecii : Oral co-trimoxazole for 3 weeks.

Bacterial Pneumonia Treatment (Hospital Acquired)

• Empiric treatment (10 days): IV ceftriaxone and amikacin are common.
• No prior IV antibiotics in the last 90 days.
• For allergy to penicillin: Oral/IV moxifloxacin and IV amikacin
• Prior IV antibiotic treatment is considered when choosing treatment.

Lung Abscess/Aspiration Pneumonia Treatment

• (Adults): IV co-amoxiclav (8 hourly) initially, and then oral afterward for 4-6 weeks.
• (Children): IV co-amoxiclav (8 hourly) for 14 days.
• Local pathogens should be considered if there's a poor clinical response and no culture results.
• Good clinical response allows a quicker switch to oral co-amoxiclav.

Bronchiectasis Treatment (Adults)

• Symptoms of sepsis or significant sputum purulence/volume: Co-amoxiclav (oral, 12 hourly) 10 days or longer
• Penicillin allergy: Macrolide (azithromycin)
• Severely ill: Ceftriaxone (IV daily) until apyrexial for 24 hours.
• Follow with Co-amoxiclav (oral, 12 hourly)
• Pseudomonas: Ciprofloxacin is added if confirmed (oral, 12 hourly, 7 days).
• Severe penicillin allergy: Moxifloxacin (oral, 7 days or IV).

Bronchiectasis Treatment (Children)

• Worsening cough with dyspnea/tachypnea and possible sepsis: Empiric treatment- IV ampicillin (6 hourly) + IV gentamicin (once daily).
• Good clinical response: Change to oral co-amoxiclav (45 mg/kg/dose amoxicillin component, 12 hourly).
• Total treatment duration is 14 days.

Respiratory Distress Treatment (Neonates)

• Hospital admission: Ampicillin (IV 5-7 days).
• Gentamicin (IV 5-7 days) in the first week.
• Treatment review 72 hours after initiation. Adjust gentamicin levels accordingly.
• Continue treatment for 10 days.

Pleural Disease Treatment (Children)

• Purulent effusion: co-amoxiclav (IV, 8 hourly, 10 days), followed by cefazolin (IV, 8 hourly) or cefalexin (oral, 6 hourly)/ co-amoxiclav (oral, 12 hourly), based on positive response
• When penicillin allergy is present: macrolide (azithromycin oral, 3 days)
• severe mycoplasma infection: IV azithromycin for 2 days and then followed by oral treatment for 3-5 days