Class action looms for these popular over-the-counter medicines

Over-the-counter medications for heartburn, reflux and morning sickness are at the centre of a class action investigation over alleged links to stomach cancer and kidney damage that could involve an estimated 100,000 Australians.

Patients who have used proton pump inhibitors (PPIs) to treat digestive issues, and subsequently developed gastric cancer or kidney damage, are eligible to join the class action investigation launched by Shine Lawyers last month.

One of those is Donna Johnstone, who claimed the heartburn medication Somac led to her developing kidney failure.

Donna Johnstone is part of the class-action investigation into alleged links between heartburn drugs and kidney damage and stomach cancer.Credit: Nick Moir

“I was taking Somac regularly. I was never informed of any ill effects or anything from it,” Johnstone said.

“One day, doctors were doing just routine blood tests when they called me. When I got there, he said my kidney function was at 19 per cent and if it got to 15 per cent, I’d have been on dialysis.

“They got me in to see a specialist, and the professor just said, straight up, this is to do with the Somac you’ve been taking.

“I then went to have a biopsy on my kidneys, and that pretty much just confirmed what he already knew, that I had kidney failure and that it was the Somac causing it.”

The inhibitors, commonly taken for digestive symptoms and disorders, work by decreasing the enzymes that line the stomach and cause stomach acid.

This process can increase gastrin levels, which is a hormone produced in the gastrointestinal, urinary tract and nervous system. An increase in gastrin has been linked to the formation of cancer cells.

The drugs involved in the investigation are Nexium or Nexium 24HR (or drugs containing esomeprazole), Losec (omeprazole), Somac (pantoprazole), Pariet (rabeprazole) and Zoton FasTabs (lansoprazole).

The drugs involved in the investigation are Nexium or Nexium 24HR, Losec, Somac, Pariet and Zoton FasTabs.Credit: Kayla Olaya and Aresna Villanueva

Zoton is prescription only, Losec and Pariet are pharmacist only and don’t require scripts, while Somac and Nexium can be found on most chemists’ shelves.

Other antacid medications such as Gaviscon use sodium alginate, sodium bicarbonate and calcium carbonate as their active ingredients, which are minerals, and are not involved in the investigation.

Director of the centre for molecular oncology at UNSW Professor David Thomas says there is a clear association of these inhibitors with gastric cancer, but conditions treated with the heartburn drugs already predispose patients to a higher risk of gastric cancer.

“So the question is whether the association is causal or indirect. Does PPI use cause cancer or contribute to it, or is the real cause the underlying gastric pathology which caused the clinician to prescribe a PPI?” Thomas said.

Pfizer (Zoton) and Takeda (Somac) declined to comment. Janssen (Pariet), AstaZeneca (Nexium and Nexium 24HR) and Pharmaco (Losec) did not respond to this masthead’s questions.

Last October, AstraZeneca paid $US425 million to settle about 11,000 lawsuits over heartburn drugs in the United States for kidney injuries.

Shine Lawyers is investigating the claim with help from US firm Milberg. Special counsel Lorne Franks said a class action could be launched within the next 12 months.

“They’ve [PPIs] come to be the most widely prescribed and some of the best-selling and most profitable drugs on the market for pharmaceutical companies,” Franks said.

“But an emerging body of research and from the outset, [have shown] concerns about their effects on potential stomach cancers and kidneys, and those concerns were pushed aside.”

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