Carcinogen in ranitidine (Zantac and generic)?

We were notified recently (by Health Canada) that ranitidine, which is both Zantac, and generic ranitidine produced by several different companies, may contain a small dose of a carcinogen NDMA.  See https://healthycanadians.gc.ca/recall-alert-rappel-avis/hc-sc/2019/70989a-eng.php

and https://www.newswire.ca/news-releases/information-update-health-canada-requests-that-companies-stop-distributing-ranitidine-drugs-in-canada-while-it-assesses-ndma-some-products-being-recalled-821911993.html

NDMA is classified as a probable human carcinogen, which means long-term exposure to levels above what is considered safe could increase the risk of cancer. We are all exposed to low levels of NDMA in some foods (such as meats, dairy products and vegetables) and in drinking water. NDMA is not expected to cause harm when ingested at very low levels.

Sandoz has issued a recall, after identifying levels of NDMA that are considered higher than would be acceptable if the drug was taken on a lifelong basis.

The other companies have not yet issued recalls.

If you are taking ranitidine, it would be advisable to reduce the dose, either from 600 mg a day to 300 mg a day, or from 300 mg a day to 150 mg a day, or stop it completely if possible.  a second choice would be to switch over to famotidine, tradename Pepcid, and 20 mg of famotidine is approximately equivalent to 150 mg of ranitidine. 

At this time, it would appear safer, and more effective, to take a PPI once a day, or twice a day if necessary, than taking ranitidine long-term.