What is the recommended treatment for pertussis?

Treatment of Pertussis

The preferred treatment for pertussis is macrolide antibiotics, with azithromycin being the first-line agent due to its effectiveness, better tolerability, and convenient dosing schedule compared to other macrolides. 1

First-Line Treatment Options by Age Group

Infants < 1 month of age

• Azithromycin is the preferred macrolide for treatment and postexposure prophylaxis due to fewer adverse events compared to erythromycin 1, 2
• Dosing: 10 mg/kg per day for 5 days as a single daily dose 1, 2
• Erythromycin is not recommended due to risk of infantile hypertrophic pyloric stenosis (IHPS) 1, 2
• Infants should be monitored for IHPS and other serious adverse events 1, 2

Infants 1-5 months of age

• Azithromycin and clarithromycin are first-line agents based on in vitro effectiveness, safety, and convenient dosing 1
• Azithromycin: 10 mg/kg per day for 5 days 1
• Clarithromycin: Specific dosing not provided in evidence, but is an acceptable alternative 1

Infants ≥ 6 months and children

• Azithromycin: 10 mg/kg (maximum: 500 mg) on day 1, followed by 5 mg/kg per day (maximum: 250 mg) on days 2-5 1
• Clarithromycin: Alternative option with similar efficacy 1, 3
• Erythromycin: 40-50 mg/kg per day (maximum: 2 g per day) in 4 divided doses for 14 days 1

Adults

• Azithromycin: 500 mg on day 1, followed by 250 mg per day on days 2-5 1
• Erythromycin: 2 g per day in 4 divided doses for 14 days 1

Comparative Efficacy and Tolerability

• Azithromycin and clarithromycin are as effective as erythromycin for treatment of pertussis 1, 4
• Azithromycin and clarithromycin are better tolerated with fewer and milder side effects than erythromycin 1, 4
• Gastrointestinal adverse events occur significantly less frequently with azithromycin (18.8%) compared to erythromycin (41.2%) 4
• Patient compliance is markedly better with azithromycin (90%) than with erythromycin (55%) 4

Alternative Treatment Option

• For patients aged >2 months with macrolide contraindications, trimethoprim-sulfamethoxazole (TMP-SMZ) is an alternative agent 1

Treatment Timing and Effectiveness

• Antibiotics administered early in the course of illness can reduce duration and severity of symptoms and lessen the period of communicability 1
• Treatment is most effective during the catarrhal phase but has limited effect on established paroxysms, emesis, or apnea if given during the paroxysmal or convalescent phases 4, 5
• Approximately 80-90% of patients with untreated pertussis will spontaneously clear B. pertussis from the nasopharynx within 3-4 weeks from onset of cough 1

Important Considerations and Precautions

• Macrolides are contraindicated in patients with history of hypersensitivity to any macrolide agent 1
• Azithromycin should not be taken with aluminum- or magnesium-containing antacids as they reduce absorption 1, 2
• Erythromycin and clarithromycin (but not azithromycin) are inhibitors of the cytochrome P450 enzyme system (CYP3A) and can interact with drugs metabolized by this system 1
• Monitor patients when azithromycin is used with agents metabolized by cytochrome P450 or drugs with changing pharmacokinetics (e.g., digoxin, triazolam, ergot alkaloids) 1
• The most common side effects of macrolides are gastrointestinal (nausea, vomiting, abdominal pain, diarrhea) and rashes 1

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
• Administration of postexposure prophylaxis to asymptomatic household contacts within 21 days of onset of cough in the index patient can prevent symptomatic infection 1