Numnuts founder Robin Smith holds a Numnuts applicator.

AUSTRALIA’S veterinary medicines regulator has approved the injectable livestock pain relief Numnuts formulation NumOcaine for over the counter sales to sheep producers, but it will only be available through veterinarians this year.

Despite the Australian Pesticides and Veterinary Medicines Authority’s decision on 15 June to reschedule NumOcaine from S4 to S5 on the Poisons Standard, Numnuts founder Robin Smith said the product would remain only available through veterinarians in 2022 and possibly into 2023.

The APVMA yesterday gazetted the rescheduling of NumOcaine – with the active ingredient lignocaine (lidocaine) — “when packaged in a container with a tamper-resistant cartridge which can only be dispensed through a rubber ring applicator for tail docking and castration of lambs.” It can also only be administered in a 1.5ml dose.

TGA uncertainty overshadows APVMA decision

However, Mr Smith said the “bitter-sweet” decision by the APVMA is still overshadowed by the Australian Veterinary Association’s attempt to overrule the Therapeutic Goods Administration’s decision in October 2021 approving NumOcaine’s rescheduling from S4 to S5. This uncertainty prompted Numnuts manufacturer Senesino to put S4 labels on about 35,000 NumOcaine bottles or 2.2million doses for 2022 use.

Mr Smith said reseller or online sales of NumOcaine would not happen until 2023 because his business needed to exhaust its supplies of S4-labelled product before manufacturing and selling any new S5-labelled stock, due to labelling laws and the company’s delicate supply/sales balance. All current NumOcaine stocks are labelled S4 and it is illegal to sell an S4-labelled drug through an S5 supply chain, he said.

The TGA’s interim decision on the AVA appeal has been delayed until the end of July and if the vets win their appeal “then everything is back to square one as far as I can gather”, Mr Smith said.

“I think essentially the TGA overtrumps the APVMA.”

“This is an unprecedented case; I don’t think it has ever happened before that a product has been approved for sale, but yet hasn’t had the chance to be sold (as S5) before it could potentially be reversed (to S4),” he said.

“In practical terms, nothing changes in 2022, the (S4-labelled NumOcaine) stock has been made and is currently flooding out of the warehouse through the vets as it has done for the past two years.”

Potential for confusion among Numnuts users

Although welcome, Mr Smith said the APVMA decision had the potential to create confusion at a critical time, with 60 percent of the company’s income coming in the next three months.

“There is a danger that producers will go to rural merchants and want to buy NumOcaine from them, but they can’t.”

Mr Smith said although the lambing and lamb marking season is about to start, he wanted to reinforce that NumOcaine will only be sold through vets in 2022.

“We communicated and promised this to all vets registered with us earlier in the year and continuously say this to farmers.

“When looking for NumOcaine pain relief, get it from your vet,” he said.

He said APVMA approved NumOcaine as an S5 under a highly restrictive use pattern.

“It can only be sold with our tamper-resistant collar on the bottle and can only be dispensed through the Numnuts device.”

He said the APVMA label requirements were legally binding and heavy fines could be applied if they were contravened.

Mr Smith said the APVMA did not rule on NumOcaine’s suitability as an S5 drug for cattle, as the company has not yet done the research trials required by the APVMA.

“We were never able to raise the R&D funds to do an efficacy trial on calves.

“The APVMA will not approve a drug for that species if you don’t have data to support it.”

NumOcaine will still be available as an S4 drug for use for marking calves, but only through veterinarians and until the S4-labelled product runs out. If Senesino wants to continue to sell an S4 NumOcaine product for cattle it will need to register a second brand with a similar label to the approved S4 label, but without inclusion of sheep. The S5 scheduled and labelled NumOcaine product for sheep will not be able to be legally used on calves, he said.

“We hope to provide an S4 preparation for cattle in future if we can find funding for calf efficacy studies,” Mr Smith said.