You are assessing a toddler who has presented with paroxysmal cough with a whoop and post-tussive vomiting. A clinical diagnosis of “whooping cough” is made and this is duly confirmed on pernasal swab cultures that reveal the growth of Bordetella pertussis.

From history, you note that he is allergic to penicillin and has been given erythromycin for a previous episode of tonsillo-pharyngitis. His mother recalls that he suffered severe abdominal pain when taking it and did not complete the course. You wonder whether newer macrolides such as azithromycin or clarithromycin could be effective alternatives to erythromycin for the treatment of pertussis.

Structured clinical question

In a child diagnosed with whooping cough [patient] are azithromycin or clarithromycin [intervention] compared …