From the Guidelines
The recommended antibiotic prophylaxis for pertussis (whooping cough) is azithromycin, with a typical adult regimen of 500 mg on day 1, followed by 250 mg daily for days 2-5, as supported by the CDC guidelines 1.
Key Considerations
- For children, the dosage is weight-based: 10 mg/kg (maximum 500 mg) on day 1, then 5 mg/kg (maximum 250 mg) daily for days 2-5.
- Alternative options include clarithromycin 500 mg twice daily for 7 days for adults (15 mg/kg/day divided twice daily for children), or trimethoprim-sulfamethoxazole (TMP-SMX) twice daily for 14 days (8 mg/kg/day TMP, 40 mg/kg/day SMX) when macrolides are contraindicated.
- Prophylaxis should be given to all household contacts and other close contacts of confirmed pertussis cases, regardless of age or vaccination status, ideally within 21 days of exposure.
Rationale
- Pertussis is highly contagious, with secondary attack rates of 80% among susceptible household contacts.
- Antibiotics work by eliminating Bordetella pertussis from the respiratory tract, preventing transmission even in asymptomatic carriers.
- Prophylaxis is particularly important for protecting vulnerable individuals such as infants, pregnant women, and those with underlying health conditions who face higher risks of severe complications from pertussis infection.
Important Notes
- Azithromycin is the preferred macrolide for postexposure prophylaxis and treatment of infants aged <1 month, due to the lower risk of infantile hypertrophic pyloric stenosis (IHPS) compared to erythromycin 1.
- TMP-SMX should not be administered to pregnant women, nursing mothers, or infants aged <2 months, due to the potential risk of kernicterus 1.
From the Research
Recommended Prophylaxis Antibiotic for Pertussis
The recommended prophylaxis antibiotic for Pertussis (Whooping Cough) is erythromycin, however, other alternatives such as azithromycin and clarithromycin are also effective and have fewer side effects 2, 3, 4, 5.
Alternative Antibiotics
- Azithromycin: a 3-day or 5-day course is equally effective as a 14-day course of erythromycin 3, 6
- Clarithromycin: a 7-day course is equally effective as a 14-day course of erythromycin 3, 4, 6
- Trimethoprim/sulfamethoxazole: a 7-day course may serve as an alternative antibiotic treatment for patients who cannot tolerate a macrolide 6
Effectiveness of Prophylaxis
The effectiveness of prophylactic treatment of pertussis contacts is uncertain, and there is insufficient evidence to determine its benefit 6. However, erythromycin prophylaxis is still recommended for close household contacts of patients with pertussis 5.
Side Effects and Compliance
Short-term treatment regimens, such as azithromycin and clarithromycin, have fewer side effects and better compliance compared to long-term erythromycin treatment 4, 6.