What is the recommended treatment for pertussis (whooping cough)?

Treatment of Pertussis (Whooping Cough)

Azithromycin is the first-line treatment for pertussis due to its once-daily dosing, excellent tolerability, and shorter treatment duration compared to other antibiotics. 1

Antimicrobial Treatment Options

First-Line Treatment: Azithromycin

• Adults: 500 mg on day 1, then 250 mg daily for 4 days (5 days total) 1
• Children: 10 mg/kg on day 1, then 5 mg/kg daily for 4 days (5 days total) 1
• Benefits: Once-daily dosing, excellent tolerability, shorter treatment duration 1, 2

Alternative Options:

Erythromycin

• Adults: 500 mg every 12 hours or 250 mg four times daily for 14 days 3
• Children: 40-50 mg/kg/day in divided doses for 14 days 3
• Limitations:
  • Associated with gastrointestinal side effects (epigastric distress, abdominal cramps, nausea, vomiting) 1
  • Risk of infantile hypertrophic pyloric stenosis in infants <1 month 4, 1
  • Multiple drug interactions due to CYP3A inhibition 4

Clarithromycin

• Adults: 1 g per day in two divided doses for 7 days 4
• Children >1 month: 15 mg/kg per day (maximum: 1 g per day) in 2 divided doses for 7 days 4
• Not recommended for infants <1 month due to potential association with IHPS 4

Trimethoprim-Sulfamethoxazole (TMP-SMZ)

• Used as an alternative when macrolides are contraindicated 1
• Contraindicated in:
  • Infants under 2 months
  • Pregnant women
  • Nursing mothers 1

Treatment Timing and Duration

• Early treatment (within first few weeks of illness) is crucial to:
  • Diminish coughing paroxysms
  • Prevent disease spread 1
• Standard treatment duration:
  • Azithromycin: 5 days
  • Erythromycin: 14 days
  • Clarithromycin: 7 days 4, 1, 3

Special Considerations

Age-Specific Concerns

• Infants <1 month: Avoid erythromycin if possible due to risk of infantile hypertrophic pyloric stenosis; azithromycin preferred 4, 1
• Infants <2 months: TMP-SMZ contraindicated 1

Treatment Failures

• Some young infants may have persistently positive B. pertussis PCR despite 7 days of clarithromycin treatment 5
• Consider extending treatment or switching antibiotics if symptoms persist

Infection Control Measures

• Isolate patients for 5 days from the start of antimicrobial therapy 1
• Healthcare workers should be excluded from work until 5 days after starting appropriate therapy 1
• Employ droplet precautions for hospitalized patients 1

What NOT to Offer

The following treatments show no evidence of benefit in pertussis and should not be used 1:

• Long-acting β-agonists
• Antihistamines
• Corticosteroids
• Pertussis immunoglobulin

Prevention Strategies

• Post-exposure prophylaxis with the same antimicrobial regimens as for treatment for all close contacts 1
• Vaccination remains the most effective prevention strategy:
  • 5-dose series of DTaP for children
  • Tdap for adolescents and adults
  • Pregnant women should receive Tdap between 27-36 weeks' gestation with each pregnancy 1, 6, 7

Remember that early treatment is essential for reducing symptom severity and preventing transmission, but antimicrobial therapy may have limited effect on the course of illness if started late in the disease.