Progress on improving software used by doctors to compile prescriptions has been "glacial", New Zealand Pharmacy Guild chief executive Annabel Young says.
Ms Young was commenting on the results of a 2008 survey of 20 Dunedin pharmacies which showed about half of the instances in which prescriptions had to be sorted out involved doctors inadvertently seeking brands not funded by Pharmac.
The situation was not likely to have improved since then, Ms Young said.
People often imagined that difficulties for pharmacists were caused by handwriting, but it was a long time since that had been a problem because most prescriptions were computer-generated.
Among the problems with the system used by prescribers was that it allowed doctors to have a "favourites list" which was not updated when the brand of a subsidised medicine changed.
If prescribers made errors they also sometimes corrected them by hand on the printed copy, but did not correct the original listing in the computer, which meant there was opportunity to repeat the error.
Lead author of the 2008 study and School of Pharmacy senior lecturer Dr Rhiannon Braund said in almost half of the interventions required by pharmacists, prescribers had given a brand name for a medicine when they actually wanted another one funded by Pharmac.
Over the week in 2008 when full data was gathered from the pharmacies, pharmacists said they spent a total of 28 hours and four minutes on 1551 interventions needed when dispensing a total of 24,059 prescription items.
The amount of time was likely to be higher because not all their time was recorded.
Dr Braund said while interventions were required in about 5% of the prescriptions, there was supposed to be zero tolerance of errors by prescribers, with prescriptions "squeaky clean when they leave the doctor's surgery".
Hospital-generated prescriptions needing intervention by the pharmacist were among those which took the longest time to sort out because often the prescribing doctor's working hours were varied.
Some district health boards recognised this and would pay for the extra time taken by pharmacists.
Dr Braund would like to see more research done comparing the situation in different parts of the country, regular updating of software used by prescribers to reflect changes in the funded brands, greater awareness among all prescribers about the need for generic names where possible, and double-checking of prescriptions.
