From the Guidelines
The recommended treatment for pertussis using macrolide antibiotics is azithromycin, given as 10 mg/kg (maximum 500 mg) on day 1, followed by 5 mg/kg (maximum 250 mg) daily for days 2-5, due to its shorter course and better tolerability 1.
Key Considerations
- Azithromycin is the preferred macrolide for postexposure prophylaxis and treatment of infants aged <1 month, as it has fewer adverse events compared to erythromycin and is not associated with infantile hypertrophic pyloric stenosis (IHPS) 1.
- For infants aged <6 months, azithromycin is administered as 10 mg/kg per day for 5 days, while for infants and children aged >6 months, it is given as 10 mg/kg (maximum 500 mg) on day 1, followed by 5 mg/kg per day (maximum 250 mg) on days 2-5 1.
- Close contacts of pertussis patients should also receive prophylactic antibiotics, such as macrolides, regardless of vaccination status to prevent further spread of the infection 1.
Treatment Regimens
- Azithromycin: 10 mg/kg (maximum 500 mg) on day 1, followed by 5 mg/kg (maximum 250 mg) daily for days 2-5 1.
- Clarithromycin: 15 mg/kg/day divided into two doses (maximum 1 g/day) for 7 days 1.
- Erythromycin: 40-50 mg/kg/day divided into four doses (maximum 2 g/day) for 14 days, although it is less commonly used now due to its longer course and more frequent side effects 1.
Monitoring and Precautions
- Infants aged <1 month who receive macrolides should be monitored for IHPS and other serious adverse events 1.
- Patients should be cautioned not to take azithromycin and aluminum- or magnesium-containing antacids simultaneously, as the latter reduces the rate of absorption of azithromycin 1.
From the FDA Drug Label
Erythromycin tablets are indicated in the treatment of infections caused by susceptible strains of the designated microorganisms in the diseases listed below: ... Pertussis (whooping cough) caused by Bordetella pertussis. Erythromycin is effective in eliminating the organism from the nasopharynx of infected individuals, rendering them noninfectious Some clinical studies suggest that erythromycin may be helpful in the prophylaxis of pertussis in exposed susceptible individuals.
The recommended treatment for pertussis using macrolides is erythromycin, which is effective in eliminating the organism from the nasopharynx of infected individuals, rendering them noninfectious 2.
- Key points:
- Erythromycin is indicated for the treatment of pertussis caused by Bordetella pertussis.
- It is effective in eliminating the organism from the nasopharynx of infected individuals.
From the Research
Macrolides in Pertussis Infection
- Macrolide antibiotics, such as erythromycin, clarithromycin, and azithromycin, are effective in treating pertussis infection 3, 4.
- The recommended treatment for pertussis is erythromycin, 40 to 50 mg/kg per day for 2 weeks, but newer macrolides like clarithromycin and azithromycin have improved absorption and a longer half-life, making them superior alternatives 3.
- Short-term treatment with clarithromycin or azithromycin is expected to be equal or superior to the standard long-term erythromycin regimen for pertussis 3, 4.
- Effective regimens for pertussis treatment include:
- Three days of azithromycin
- Seven days of clarithromycin
- Seven or 14 days of erythromycin estolate
- 14 days of erythromycin ethylsuccinate 4
- Azithromycin is recommended as the first-line antibiotic for the prophylaxis and treatment of pertussis due to its better tolerance compared to other macrolide antibiotics 5.
- The minimum inhibitory concentrations (MICs) of erythromycin, clarithromycin, azithromycin, ciprofloxacin, and trimethoprim/sulfamethoxazole for strains of Bordetella pertussis have remained stable over the years, with no significant development of resistance mechanisms 6.
- Azithromycin and clarithromycin offer distinct advantages over erythromycin, including improved pharmacokinetics and antimicrobial activity 7.