An impending ban on over-the-counter codeine products has sparked an increase in consumer complaints and fears patients are stockpiling it.

The Therapeutic Goods Administration has decided to follow the lead of the United States and many European nations and require a prescription for codeine products. The changes sparked objections in the Coalition party room in October but is set to apply from 1 February.

The Consumer Health Forum supports the change to tackle dependence on opioids and the risk of overdose.

But the forum’s policy manager, Jo Root, said it had received anecdotal reports that people were stockpiling codeine products such as Nurofen Plus ahead of the ban.

“There is some evidence they are buying as many packets as they can get their hands on,” she said. “It’s not the outcome we wanted but it’s what happens when you give people notice of an impending ban.”

Pain Australia is running a campaign, Real Relief, that argues alternatives are more effective and prepares consumers for the impending ban.

The chief executive of Pain Australia, Carol Bennett, said the campaign’s message was that “codeine is not particularly effective for long-term chronic pain” .

“If you’re using codeine for longer than three days, that should be a wake-up call: what else do I need to be doing to manage my pain?” she said. “One of the [issues] around codeine use is it does create a dependence ... It’s very difficult if you’re reliant on codeine for pain relief. It’s scary to look for an alternative [patients] think won’t be effective.

Bennett is less concerned about stockpiling, because some drug companies have stopped supplying over-the-counter variants and pharmacies have stopped ordering them, so they are already unavailable in many chemists.

A spokesman for the Pharmacy Guild of Australia, Greg Turnbull, said “a lot of consumers are not happy about it at all”, with big spikes in complaints after media reports on the ban.

“Lots of people use codeine safely and appropriately to deal with migraines, toothache and period pain,” he said. “A bureaucracy telling them ‘No, you can’t have that’ won’t be well received.”

Turnbull said TGA statistics showed about 80% of codeine consumers bought only 20% of the volume, meaning the majority were using it safely, but the figures suggested possible inappropriate use among the other 20% of consumers.

“The people who say they use it every week are exactly those who shouldn’t be, but the majority using it safely are not being taken into consideration.”

Turnbull said codeine should not be sold in dangerous amounts and 70% of pharmacies used a system of real-time recording to prevent patients buying too much.

That safeguard would be lost when the ban came into place, he said, because there was no real-time recording for prescription medicines, raising the risk of “doctor-shopping”.

“No doctor knows if you have gone to a different doctor the day before to get a script for the same medicine.”

But Turnbull said the Pharmacy Guild had accepted they were a fait accompli and would work to implement the changes.

Root said CHF had received a handful of complaints from patients worried about pain relief after February because they “need” codeine but said they should be directed to a medical professional.

Of the group of Liberal MPs who raised concerns in the party room, Jason Falinski and Tim Wilson said they would wait to see how consumers responded to the ban.

“They’ll go through the process and be told you need a prescription – then I expect a pushback,” Wilson said.

The Liberal MP Craig Kelly said several chemists in his electorate had run out of codeine and faced “very upset” consumers who were told to get a prescription.

Kelly is concerned by doctor shopping, arguing “demand finds another way around the barrier” and wants a review of the ban’s effectiveness after it is in place.