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 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.

Your question to the PBAC

Sir, In the last month I have prescribed 56 tablets of bismuth subcitrate as part of the eradication of H. pylori , 5 oxazepam tablets for a patient distressed after an unexpected bereavement and acyclovir 200 mg x 50 for initial genital herpes. On each occasion, I have been phoned by a different pharmacist asking if I could prescribe the maximum quantity authorised in the Schedule of Pharmaceutical Benefits. In the case of the first two drugs, the reason given was that to cut packs into portions would mean that the extra portions would simply linger on the pharmacist's shelves without any hope of being sold. In the last case, the pharmacist only had packs of 90 tablets. Prescribing more than required is costly and potentially dangerous for the patient. Is there any way in which a doctor's considered prescription can be translated into action without financial loss to the pharmacist?

Max Kamien
Professor of General Practice
University of Western Australia
Perth, W.A.

PBAC response

There is no compulsion under the Pharmaceutical Benefits Scheme to prescribe the maximum quantity of a drug as a pharmaceutical benefit if the medical practitioner considers a lesser quantity is sufficient for the patient's requirements (unless the maximum quantity is marked with a double dagger in the Schedule of Pharmaceutical Benefits). In fact, the Pharmaceutical Benefits Advisory Committee would prefer practitioners to prescribe the quantity that is needed rather than the maximum allowable quantity.

If a practitioner prescribes less than the maximum quantity, where the maximum quantity coincides with the standard pack, the pharmacist is compensated for dispensing the 'broken quantity' according to the 'Wastage Factor Table' (in 'Section1-Explanatory Notes' of the Schedule of Pharmaceutical Benefits). For example, if half the listed maximum quantity is prescribed (as in the case of 56 bismuth subcitrate tablets from a pack of 112), the payment to the pharmacist is 62% rather than 50% (ignoring the dispensing fee). There is thus a wastage factor of 12% built in, in this case.

In relation to acyclovir tablets 200 mg, the maximum quantity for initial treatment of moderate to severe genital herpes is 50 tablets, not 90 tablets, which may be dispensed from a pack of 90 tablets or two packs of 25 tablets. The pharmacist's remuneration in this case is based on supply from two packs of 25 tablets, and 'broken quantity' pricing will not apply.