The TGA is currently testing to see whether Australian ranitidine supplies are also contaminated with NDMA
Manufacturers of the heartburn medication ranitidine (Zantac) are pulling it from the shelves because a chemical that is known to cause cancer in laboratory rats has been discovered inside some tablets.
At least seven companies have recently decided to recall ranitidine in Australia: Aspen, Symbion, Alphapharm, Apotex, Cipla, Generic Health Pharmacy Choice and Sandoz.
N-nitrosodimethylamine (NDMA) was last month detected at low levels in ranitidine drugs overseas.
This chemical is classified by the WHO as a probable human carcinogen. In experiments with laboratory animals it can cause liver disease, liver cancer and lung cancer.
Following a public announcement by the FDA in the US about the finding, Sandoz voluntarily recalled ranitidine capsules. US retail giants Walgreens, Rite Aid and CVS have also stopped selling the drug.
The FDA’s testing found “unacceptable levels” of NDMA in samples of ranitidine.
The TGA is currently testing to see whether Australian ranitidine supplies are also contaminated with NDMA.
“It’s not clear how the ranitidine formulations have become contaminated with NDMA,” two pharmacists at The University of Sydney wrote on The Conversation website.
“A similar chemical, dimethylamine, is used in the synthesis of ranitidine, and it may be possible some NDMA is created when the drug is made,” they said.
“Alternatively, ranitidine may be broken down, producing NDMA, during storage.”
The NDMA quantity in the medication would only raise the risk of cancer if the drug was taken over many decades, the TGA said.
However, this low risk might outweigh the benefits of the drug, which is taken for heartburn symptoms.
“For this reason, doctors who are treating a patient with ranitidine should consider alternative management where clinically appropriate, which may include an alternate H2 receptor antagonist, proton pump inhibitors, and/or diet and lifestyle modification,” the TGA said.
The NDMA incident might cause a flurry of prescriptions changes, which could result in medication shortages, the TGA warned.
