Readers are invited to write in with their questions about decisions of the Pharmaceutical Benefits Advisory Committee (PBAC). Australian Prescriber publishes selected questions from readers, together with answers from the PBAC. Questions may address issues such as regulatory decisions, pharmaceutical benefits listings and withdrawals.
This exclusive arrangement helps Australian Prescriber readers understand how the contents of the Pharmaceutical Benefits Scheme (PBS, see www.pbs.gov.au) are determined.
Letters and responses are reviewed by the Editorial Executive Committee and may be edited before publication. It may not be possible to reply to all individual questions.
Sir, - In consultation with an orthopaedic surgeon and infectious diseases expert, I have recently treated a patient for chronic osteomyelitis. After one month of intravenous antibiotics, the infectious diseases consultant advised a prolonged course of oral rifampicin and fusidic acid. This is an accepted indication for rifampicin according to the current Antibiotic Guidelines. However, according to the current Schedule of Pharmaceutical Benefits, rifampicin is only available as a pharmaceutical benefit for tuberculosis, leprosy and for the prophylaxis of haemophilus and meningococcal disease.
Could you please explain why these restrictions are at odds with current expert recommendations?
Geoffrey L. Campbell
When considering the availability of a drug as a pharmaceutical benefit, and any restriction that would apply to its prescribing, the PBAC takes into consideration the indications for which the drug is registered in Australia. In the case of rifampicin, the approved indications are those recommended by the Australian Drug Evaluation Committee (ADEC).
The indications for which a drug is approved are listed in the approved product information. Those for rifampicin are tuberculosis, leprosy, meningococcal disease and Haemophilus influenzae type b.
Since rifampicin is not registered for the treatment of chronic osteomyelitis, the PBAC is not in a position to recommend its listing for the treatment of this condition.
The inclusion of rifampicin and fusidic acid in the Antibiotic Guidelines for treatment of osteomyelitis, and not in the product information, is one of those instances outlined by Dr M.L. Mashford in his article 'Product information: what does it define?' (Aust Prescr 1994;17:39-41) where current clinical practice and the recommendations in the Guidelines deviate from the product information.
I understand that the ADEC has indicated that there may be a place for rifampicin in the treatment of severe MRSA infections, such as osteomyelitis, and that any application to extend the approved indications for rifampicin to include such use would be likely to be considered favourably. However, presumably, such an application from a pharmaceutical company, which would be in the best position to compile the necessary documentation, has not been forthcoming.