Singapore — The Health Sciences Authority (HSA) has recalled three brands of high blood pressure medicines that contain the ingredient losartan as the drugs contain higher than acceptable levels of a potentially harmful impurity, said the authority on Thursday (March 28).

The affected products are the 50mg and 100mg variants of Hyperten, Losagen and Losartas, which are distributed by local suppliers Goldplus Universal, Medicell Pharmaceutical and Apotheca Marketing, respectively.

The ingredient losartan potassium is manufactured by Indian pharmaceutical firm Hetero Labs Limited.

According to the Ministry of Health (MOH), there are about 137,000 patients in Singapore using the brands of losartan medicine that have been recalled and about 130,000 of these patients were prescribed with Losartas at public healthcare institutions.

Professor Ding Zee Pin, a cardiologist at the National Heart Centre Singapore, said: “There is no immediate health risk associated with taking the affected medicines and patients are advised not to stop or change treatment on their own.”

“As Losartan is used to treat high blood pressure, stopping the medicine without replacement of other equivalent medication can increase the risk of poor control of blood pressure,” added Prof Ding, who is a member of the HSA’s Expert Panel on Nitrosamines.

INCREASED RISK OF CANCER

The recalled products were found to contain trace amounts of a nitrosamine impurity which is above internationally accepted levels, said the HSA.

Nitrosamines are environmental contaminants found in food or in the environment in very minute amounts.

HSA said that “exposure to nitrosamines at high quantities over a long-term period may potentially increase the risk of cancer”.

PUBLIC HEALTHCARE INSTITUTIONS AFFECTED

The MOH said in a statement that there is a “sufficient supply of high blood pressure medication” and public healthcare institutions will be reaching out to their patients.

Patients whose medical appointments are scheduled before July 1 should proceed with their appointments and will be advised by their doctors on suitable alternative medicines.

Patients whose medical appointments are scheduled on or after July 1 will be contacted for an earlier consultation and/or medication review.

There are still seven other Losartan products available in Singapore.

The public healthcare sector has made additional orders of these unaffected brands of Losartan and additional supply will arrive progressively from a few weeks’ time, the MOH said.

The MOH added that importers of these unaffected brands will also be setting aside additional supplies for private healthcare providers.

Medical practitioners are advised to initially prescribe medication for high blood pressure on a one-month basis, to ensure that all patients are able to promptly receive the medication they need, said the MOH. The ministry added that this may be the practice for the next six months.

At public healthcare institutions, patients currently on Losartan will pay the same price or lower if they switch to replacement medications in the interim period, the MOH said.

The MOH added that charges incurred for services such as additional consultations will be waived and patients who return the affected brands of medicine at their public healthcare institutions will be refunded.

CHANGES TO MANUFACTURING PROCESS

The HSA noted that since end-February 2019, several losartan medicines were recalled overseas due to the presence of the said nitrosamine impurity and the agency tested all locally marketed losartan products for the impurity by March 21.

The authority is working with companies and international regulatory agencies to verify the cause of the contamination and formulate measures to address the issue.

Companies will be required to make necessary changes to their manufacturing process to ensure that the medicines do not contain these impurities in the future, added the HSA.