Postexposure antibiotic prophylaxis for pertussis

If indicated, start postexposure antibiotic prophylaxis for pertussis as soon as possible. The benefit of postexposure prophylaxis outweighs the harms of antibiotic use if prophylaxis is started within 14 days after first contact with the patient with pertussis. Incubation periods of up to 21 days can occur so consider treating high-risk patients within 21 days of first contact with the patient with pertussis.

If postexposure antibiotic prophylaxis is indicated for children with pertussis, useCDC, 2005Communicable Diseases Network Australia (CDNA), 2024:

1azithromycin azithromycin

term neonate and child younger than 6 months: 10 mg/kg orally, daily for 5 days

child 6 months or older: 10 mg/kg up to 500 mg orally, on day 1, then 5 mg/kg up to 250 mg daily for a further 4 days. Total duration of therapy is 5 days

OR

2clarithromycin (child 1 month or older) 7.5 mg/kg up to 500 mg orally, 12-hourly for 7 days clarithromycin

OR

2trimethoprim+sulfamethoxazole (child 1 month or older) 4+20 mg/kg up to 160+800 mg orally, 12-hourly for 7 days. trimethoprim + sulfamethoxazole

Administration of the oral formulation of clarithromycin to children may be difficult because the product is often unpalatableElgammal, 2023Matsui, 1997; consider using azithromycin if possible.

If postexposure antibiotic prophylaxis is indicated for adults with pertussis, useAltunaiji, 2007:

1azithromycin 500 mg orally, on day 1, then 250 mg orally, daily for a further 4 days. Total duration of therapy is 5 days azithromycin azithromycin azithromycin

OR

1clarithromycin 500 mg orally, 12-hourly for 7 days clarithromycin clarithromycin clarithromycin

OR

2trimethoprim+sulfamethoxazole 160+800 mg orally, 12-hourly for 7 days. trimethoprim + sulfamethoxazole trimethoprim+sulfamethoxazole trimethoprim+sulfamethoxazole

Azithromycin and clarithromycin are the preferred macrolides for postexposure antibiotic prophylaxis for pertussis; there is no evidence to support the use of roxithromycin and although erythromycin is active against B. pertussis, it is poorly tolerated and requires more frequent dosingLangley, 2004.