What is the treatment for pertussis?

Treatment of Pertussis

Macrolide antibiotics are the preferred treatment for pertussis, with azithromycin being the first-line agent for most patients due to its effectiveness, better tolerability, and convenient dosing schedule. 1, 2

First-Line Treatment Options by Age Group

• Infants <1 month of age: Azithromycin is the preferred agent due to its effectiveness and safety profile 1

  • Erythromycin and clarithromycin are not recommended for this age group due to risk of infantile hypertrophic pyloric stenosis (IHPS) 3, 4

• Infants 1-5 months of age: Azithromycin or clarithromycin are recommended as first-line agents 1

  • Azithromycin dosing: 10 mg/kg once daily for 5 days 1
  • Clarithromycin dosing: Based on weight, typically divided into two daily doses for 7 days 1

• Children ≥6 months and adults: Any macrolide can be used, with azithromycin generally preferred 2, 1

  • Azithromycin dosing for children: 10 mg/kg (maximum: 500 mg) on day 1, followed by 5 mg/kg per day (maximum: 250 mg) on days 2-5 1
  • Azithromycin dosing for adults: 500 mg on day 1, followed by 250 mg per day on days 2-5 1
  • Erythromycin dosing: Usually administered in 4 divided daily doses for 14 days 2, 4

Alternative Treatment Options

• For patients aged >2 months with macrolide contraindications: Trimethoprim-sulfamethoxazole (TMP-SMZ) is recommended 2, 5
  • This alternative should be considered for patients with allergies or intolerance to macrolides 5

Treatment Timing and Effectiveness

• Early antibiotic treatment (during catarrhal stage) can reduce duration and severity of symptoms and decrease the period of communicability 2, 5
• Even when started during the paroxysmal phase, antibiotics can reduce disease severity and duration 6
• Antibiotics eradicate B. pertussis from the nasopharynx of infected persons, whether symptomatic or asymptomatic 2
• Without treatment, 80-90% of patients will spontaneously clear B. pertussis from the nasopharynx within 3-4 weeks from onset of cough 2
• Untreated and unvaccinated infants may remain culture-positive for >6 weeks 2

Comparative Efficacy and Tolerability

• Azithromycin and clarithromycin are as effective as erythromycin for treatment of pertussis 1, 7
• Newer macrolides (azithromycin, clarithromycin) have better tolerability and fewer side effects than erythromycin, improving treatment compliance 1, 8
• Short-course therapy with azithromycin (5 days) or clarithromycin (7 days) has shown comparable efficacy to standard 14-day erythromycin regimens 7

Important Considerations and Precautions

• Macrolides are contraindicated in patients with history of hypersensitivity to any macrolide agent 1
• Erythromycin and clarithromycin (but not azithromycin) inhibit the cytochrome P450 enzyme system (CYP3A subclass) and can interact with other drugs metabolized by this system 2, 4
• Erythromycin has been associated with infantile hypertrophic pyloric stenosis (IHPS) in neonates, with risk increasing with longer treatment duration 4
• Azithromycin should not be taken with aluminum- or magnesium-containing antacids as they reduce absorption 1
• Antibiotics should not be used prophylactically at late stages of pertussis to prevent secondary bacterial complications, as this approach may increase risk of complications 9

Postexposure Prophylaxis

• The same antimicrobial agents and dosing regimens used for treatment are recommended for postexposure prophylaxis 1
• Prophylaxis should be administered to close contacts, especially in exposure settings that include infants <12 months or women in the third trimester of pregnancy 1
• Close asymptomatic contacts can be given postexposure chemoprophylaxis to prevent secondary cases; symptomatic contacts should be treated as cases 2