health & science

MPI ‘still considering’ drug ads amid antibiotic fears

It's easier for farm animals to be prescribed some "last resort" antibiotics than it is for people to get similar drugs. As vets try to shrink their use of these top-shelf medicines they are asking - again - for MPI to help them by banning direct advertising to farmers, reports Eloise Gibson.

The Ministry for Primary Industries is still considering pleas by vets to stop direct marketing of antibiotics to farmers, two years after Newsroom reported on vets’ worries and six years after the Ministry first said it was re-considering antibiotic advertisements.

Vets say direct marketing of animal antibiotics to farmers serves no good purpose and creates unnecessary pressure on vets to prescribe top-shelf antibiotics – medicines that are supposed to be kept in reserve because they are critical to saving people’s (and animals') lives from dangerous infections. 

New Zealand is one of only a few developed countries that allows advertising of antibiotics directly to the end user, and the ads often target dairy farmers.

Two years ago, the head of veterinary services for the New Zealand Veterinary Association, Callum Irvine, told Newsroom that vets wanted MPI to stop direct marketing as vets tried to do their part to combat rising antibiotic resistance, a threat that one British government report predicts will overtake cancer as a global killer by 2050.

Irvine said in early 2017 that direct ads by pharmaceutical companies created pressure on vets to prescribe the most precious classes of antibiotic for commercial convenience rather than animal welfare reasons: “Our concern is that this advertising may lead to pressure on vets to prescribe antibiotics on the basis of reduced withholding times (from milking) or convenience of use,” he said. Such antibiotics can clear from the animal's system quicker, meaning less wasted milk. 

As early as 2013 the ministry said it was looking at controls around antibiotic marketing to see if changes were needed. In 2017 MPI told Newsroom it “had initiated a discussion with key stakeholders regarding advertising of antibiotics,” and was “considering key stakeholder feedback” but hadn’t decided what to do.

This month, it said it hadn’t decided. “MPI is reviewing the practice of marketing antimicrobials directly to farmers, and how restrictions around marketing and advertising will change going forward. We’ll be in a position to make a decision once we’ve completed the review,” it said.

Mark Bryan, a vet and researcher who chairs the antimicrobial resistance group of the New Zealand Veterinary Association, said last week that there was no doubt that marketing to farmers created unnecessary tension, as vets move to adopt more parsimonious prescribing habits.

Faced with MPI figures showing then-rising sales of top-tier antibiotics to farmers, Bryan’s group came up with a much-publicised aspirational goal for vets to no longer use antibiotics for routine health matters by 2030. Since then, MPI figures and figures from a study of vets by Bryan show sales of those antibiotics classed as most critical for human health have generally fallen, replaced in some cases by rising use of penicillin, which is considered less critical to human medicine. But MPI has not resolved the marketing issue. 

“There’s always been a high level of unease around the veterinary profession around direct marketing …. there’s no question that vets do feel pressure from farmers if they’ve seen a drug. Companies wouldn’t spend money on marketing if they didn’t feel it made a difference. There’s not a huge amount of marketing but it does happen and I don’t think it needs to happen,” Bryan told Newsroom.

While New Zealand farms have lower-than-average antibiotic use, they do use some of the most precious classes of antibiotics – such as third and fourth generation cephalosporins and macrolides – to treat farm animals. Bryan says vets are keen to avoid being banned from using these drugs because they can be the best (or only) treatment for some difficult infections, such as a bout of lameness that hit Canterbury dairy cows during a particularly dry year a few years ago. When a hoof or other infection gets gnarly or into the bone, lower-tier antibiotics like penicillins might take a long time to clear it or not work at all, says Bryan.

As doctors and vets try to slow or prevent the rise of antibiotic-resistant superbugs, the World Health Organisation (WHO) has divided antibiotics into tiers with medicines such as third and fourth generation cephalosporins and macrolides in the top, “highest priority critically important” group, because they are one of the few options left for treating some life-threatening infections in people. Medicines in the top-tier are the ones that doctors and vets are supposed to keep in reserve for use only as a last resort, because the more often these classes of drugs are used, the higher the risk that they will foster and spread bacteria that can deactivate even the best antibiotics. That would leave doctors helpless to treat a growing number of infections. Most at risk from resistant superbugs are babies, the elderly and people in hospital, who are vulnerable to bacteria getting into parts of their bodies where they shouldn’t ordinarily be, via tubes and respirators.

While there’s no evidence yet of animals passing resistant microbes to people, microbiologists, vets and even the Prime Minister’s new Chief Science Advisor, Juliet Gerrard, say it makes sense to keep an eye on vets prescribing habits and start doing more thorough environmental monitoring to see if, for example, resistant microbes in cow poop are making their way into waterways. Hospitals and GPs are being urged to take care too, given New Zealand has high antibiotic use and high rates of infectious diseases that require antibiotics, such as rheumatic fever, respiratory infections and skin infections. 

Because vets and doctors have different professional structures, it is easier for vets to prescribe cows and pets some of the top-tier antibiotics than it is for GPs to prescribe them to people. For example, people can usually only get access to the newest generation cephalosporins – the best and fastest ones that were developed when the earlier versions became ineffective – through a hospital pharmacy, and then only if they’ve been diagnosed with a particularly gnarly infection. Vets, by contrast, can give animals similar drugs like Ceftiofur without any special dispensation, placing the pressure on individual vets to make the right decisions. With more run-of-the-mill antibiotics like penicillin, a vet may not even see the animal before it takes the medicine because farmers can get a special allowance to keep a stash on hand for treating urgent cases of mastitis, for example, says Bryan. “But there would be instructions that if it goes on too long or there are repeat infections we need to do cultures and there might be something else we can administer,” he says.

The Veterinary Association’s stewardship policy says that: “Antibiotics considered of high importance in human medicine should be avoided unless there is good reason to use them (e.g. where other available drugs are not likely to be effective).” To help, the vet industry has created a “traffic light” system to encourage individual vets to be more frugal, asking them to look at “green” light (less critically valuable) medicines before moving up to the orange and red tiers. The initiative seems to have helped – the latest MPI figures show a noticeable downward trend in cephalosporin and macrolide sales, and vet industry prescribing data tracked by Bryan also shows an improvement. Some practices have gone so far as to label all their medicines red, orange or green or to stop using Ceftiofur altogether, says Bryan. 

However, this careful stewardship system is voluntary. Juliet Gerard’s office noted in a recent information sheet that many vet practices don’t have prescribing policies. “Although acknowledged as important by veterinarians, the scale of the risk of  antimicrobial resistance is not well understood amongst farmers or veterinarians,” said the fact sheet. Gerard told Newsroom late last year that she planned to raise the issue of antibiotic resistance with Prime Minister Jacinda Ardern when they met before Christmas.

Gerard told Newsroom she’d asked vets why their prescribing practices seemed less restricted by top-down oversight than doctors', and was told vets didn’t have the same professional hierarchies. “Most hospitals have restrictions on 3rd and 4th generation cephalosporins so you wouldn’t be able to prescribe them unless it was endorsed by a specialist. But when I spoke to vets there isn't the same hierarchy of veterinary practice, so there is no equivalent," she said. "But the vets I spoke to said there was growing awareness and the MPI numbers back that up.”

According to antibiotic monitoring by ESR, GPs don’t prescribe the top-tier antibiotics in the community, and a study at Auckland DHB found prescribing rates were fairly low even inside hospitals. “Most people in hospitals wouldn’t get cephalosporins or macrolides,” Gerard said.

But one infectious disease expert says there’s no reason vets, too, couldn’t be required to get a second, specialist opinion before using the most critical antibiotic classes. Bryan, the vet, says vets would probably be comfortable with that. 

Otago University biochemistry professor Kurt Krause, an infectious disease expert, has previously voiced concerns about rising sales of the antibiotic Ceftiofur to farmers, questioning whether something simpler could be used instead. He said he was pleased to see sales of that drug falling in the latest MPI report, but he was “scared” to see another critical type of antibiotic, aminoglycocides, rising. (A separate but more recent study of vets by Bryan did not show this increase). “Aminoglycocides are extremely important to people who have resistant gram negative bacteria, and they tend to be used more in hospitalised treatments,” said Krause.

Despite his concern, Krause was not in favour of preventing vets from using these medicines. “I’m not a big ban person,” says Krause. But: “You could have a standard set of drugs available to vets and a second tier that requires a phone call to the appropriate person. Maybe they need antimicrobial specialists within veterinary science who can be that resource.”

Bryan said vets would likely be comfortable with that kind of oversight, as long as they kept access to the critical drugs. The question was whether MPI would have time to administer that kind of system, he said.

“I can see a place for it. Because some vet clinics just removed Ceftiofur from use, for example. And I’m not a huge fan of that because I think there are circumstances when it’s the best thing for animal welfare. I’d like them to have a process where if it’s the right drug they can use it and having a regional person [overseeing prescriptions] would be quite appropriate," he says.

"The question would be the framework. MPI would be the obvious people to administer it but they are a bit busy. But in the longer term I think it would be [viable] — it’s a classic situation of, you either regulate yourself, or you get regulated, or a mixture of both," says Bryan.

"We could point toward reduced use of third generation cephalosporins and that would go a long way to show we’re making a difference, and if there needs to be a regulatory process around that, that’s fine too. What we don’t want is a knee-jerk thing that compromises animal welfare in the short term.”

*The Ministry of Health doesn't know how much 3rd and 4th generation cephalosporins or other top-shelf drugs are being used in hospitals around the country. PHARMAC has promised to get the data for Newsroom but couldn't supply it before this story went to print. 

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