University of Otago pharmacologist Associate Prof David Reith is one of several researchers calling for an urgent change in drug labelling in Australia and New Zealand to ensure the active ingredient of medicines is displayed more prominently than the brand name.
Prof Reith and nine other researchers co-authored a paper published in this month's Medical Journal of Australia on the issue.
It stated increasing brand substitution due to the proliferation of generic medicines added to the potential for confusion and the likelihood of "medication misadventure".
As 40% of patients older than 70 years took more than five medicines, they were increasingly vulnerable to medication errors.
In an interview, Prof Reith used the example of two liquid medicines containing paracetamol on which the brand names were clear but the fact the active ingredient was paracetamol was displayed in small type on only one panel of the packet.
Exceeding the recommended dose of paracetamol over a prolonged time could result in liver damage.
Paracetamol poisoning was responsible for about half the cases of liver failure in the United States, he said.
The risk was that patients might not be aware two medications with differing names had paracetamol as the active ingredient and could exceed safe doses by using both medicines at the same time.
In the article, the authors said although Australian labelling guidelines called for active ingredients to be prominently and equally displayed, these were voluntary and industry compliance was low.
While there might be marketing sense behind the choice of a catchy name for a new product, generic brands were rarely marketed to prescribers, and pharmacists' decisions were more likely to be based on cost rather than persuasive advertising.
"Consequently, as a first step companies that use the active ingredient name within their brand name should be supported," the article said.
Prof Reith said there should be some way a manufacturer could display its brand on the product, but suggested this could concentrate on the drug company's logo rather than a particular name for the medication.
Another possibility would be using the active ingredient name and then the brand as in "Paracetamol by Pamol".
Prof Reith would like to see the change in labelling in two years' time which would allow time for manufacturers to alter packaging.
"It is not possible to make a change overnight."
He considered the change would not necessarily have to be the result of a law change - "manufacturers can come to an agreement or just do it".
In the meantime, he urged patients to always read the ingredients on their medications and to be aware if they were taking more than one medication with the same active ingredient.
