Call for wider access to preferred pertussis drug

AUSTRALIAN infectious disease experts are calling for azithromycin (Zithromax) to be made more widely available for the prophylaxis and treatment of pertussis.

Writing in the MJA, experts from the Sydney Children’s Hospital and the University of NSW said the drug was better tolerated than other antibiotics such as clarithromycin, erythromycin and trimethoprim-sulfamethoxazole and had better compliance.

They are calling for approval of the drug by the TGA for pertussis treatment and PBS listing.

Currently, the 9th Immunisation Handbook recommends azithromycin as the first-line antibiotic for pertussis prophylaxis and treatment.

The experts said azithromycin had a shorter treatment course (five days compared to seven for other drugs), fewer gastrointestinal side-effects, and was the preferred agent for those younger than one month old.

The call comes as an outbreak of pertussis continues across NSW. From January to March this year, NSW Health recorded 5045 cases of reported pertussis. During the whole of 2008, 8855 cases were recorded.

Victorian GP Dr Greg Rowles, a member of the National Immunisation Committee, agreed the drug should be more accessible.

“It is not uncommon for patients to not tolerate erythromycin or clarithromycin, which are usually used first-line in general practice [due to the PBS listing], because of gastrointestinal side-effects,” he said.

A spokeswoman for Pfizer, the manufacturer of azithromycin, said the company would be looking into the issue soon.

Meanwhile, the National Prescribing Service is urging adolescents and adults to be vaccinated against pertussis, which it says is now more common in those aged 15 years or older than in children, most likely because of waned immunity.

MJA 2009;190:388-89