Indian doctors have advised patients here to avoid over-the-counter (OTC) use of popular antacid ranitidine, following concerns over its contamination by cancer-causing substances, with the Central Drugs Standard Control Organisation (CDSCO) now having started the process of “checking for any adverse reactions of the drug”.
CDSCO has written to State regulators, asking that they “communicate to the manufacturers of ranitidine active pharmaceutical ingredient (API) and formulations under your jurisdiction to verify their products and take appropriate measures to ensure patient safety”.
The drug regulator notes that it is aware of reports from other countries that some ranitidine medicines contain a nitrosamine impurity called N-nitrosodimethylamine (NDMA) at low levels.
The Drugs Controller General of India (DCGI) V.G. Somani in the letter further notes that NDMA has been classified by the International Agency for Research on Cancer as “probably carcinogenic” to humans.
“The drug ranitidine is approved for multiple indications in the country and available in various formulations including tablets, injections, etc. The drug is a prescription drug included in Schedule-H and therefore it should be sold by retail only under prescription of Registered Medical Practitioner,’’ noted the letter.
Final report awaited
Doctors, however, maintained that NDMA causes harm in large amounts. Dr. Lalit Verma, Paediatric Gastroenterologist, Surya Hospitals, Mumbai, said: “While there is no need to panic, indiscriminate use of the drug without proper assessment and prescription should be avoided. We are also waiting for the U.S. Food and Drug Administration’s (USFDA) final report.”
On September 13, the USFDA said in a release that it had learned of some ranitidine medicines, including those commonly known by the brand name Zantac, contained “low levels” of NDMA. It added it was evaluating whether these levels of the substance posed a risk to patients. Dr. Reddy’s Laboratories maintained that it was suspending supply of its ranitidine “worldwide” as a precaution.
The USFDA had noted that NDMA levels in ranitidine from preliminary tests barely exceed amounts might be expected to be found in common foods. NDMA, an environmental contaminant found in water and foods, has the same impurity that the USFDA had investigated in blood pressure drugs valsartan and losartan over the last year.