SINGAPORE: Three brands of high blood pressure medicine containing the ingredient losartan have been recalled after they were found to contain higher than acceptable levels of a potentially harmful impurity, said the Health Sciences Authority (HSA) on Thursday (Mar 28).
The brands involved – Losartas, Losagen and Hyperten – are used by about 137,000 patients in Singapore. The affected products are the 50mg and 100mg tablets.
WHAT IS LOSARTAN?
Losartan is an ingredient found in medicine used to treat hypertension, or high blood pressure. It is an angiotensin II receptor blocker (ARB), a class of drugs that block the action of a chemical in the body that causes the tightening and narrowing of blood vessels.
ARBs help lower blood pressure and improve blood flow, which reduces the risk of heart disease, heart attack, and stroke.
Losartan can also be used to treat diabetic nephropathy, a kidney disease caused by diabetes. Patients who have high blood pressure and left ventricular hypertrophy - a condition that causes the thickening of the heart’s left ventricle - may also take losartan to reduce their risk of getting a stroke.
The drugs often come in the form of oral tablets, which can be taken with or without food. Patients with high blood pressure usually take 50mg to 100mg once a day.
WHAT ARE THE RISKS AND SIDE EFFECTS OF TAKING THIS MEDICINE?
According to Healthline, common side effects of taking losartan include upper respiratory infections, dizziness, back pain, fatigue, diarrhoea, low blood sugar and high or low blood pressure.
In some cases, losartan may also cause high potassium levels in blood, allergic reactions, kidney disease and weight gain.
WHO SHOULD AVOID IT?
Drugs.com warns that pregnant women should not take losartan, as it can cause death or injury to the fetus.
It should also be avoided by diabetics who take medication containing aliskiren, a renin inhibitor, and children below the age of six.
Losartan can also worsen kidney disease in patients with existing problems, according to Healthline.
Patients taking a diuretic, other blood pressure medication, lithium or aspirin and other nonsteroidal anti-inflammatory drugs such as ibuprofen should also inform their doctor before taking medication containing losartan.
WHY WERE DRUGS RECALLED IN SINGAPORE?
The recalled drugs were found to contain amounts of a nitrosamine impurity above internationally accepted levels.
Exposure to nitrosamines at high quantities over a long-term period may potentially increase the risk of cancer.
HSA said the impurities are by-products produced in trace amounts during the manufacturing process. Seven other brands of losartan medicine sold in Singapore are not affected by the recall.
READ: Patients worried after recall of high blood pressure medicine, but doctors say there is no cause for alarm
WHAT SHOULD AFFECTED PATIENTS DO?
First of all, do not stop taking your medication without consulting a doctor.
According to HSA, suddenly stopping medication can post a greater and more immediate health risk to patients. Without a replacement, patients are at higher risk of poor blood pressure control.
The Ministry of Health (MOH) warns that this could lead to heart attacks and strokes.
Those who are unsure if they have been using an affected product should contact their healthcare providers, said MOH.
Patients currently prescribed the medicine may be offered alternatives by their doctor. This includes brands unaffected by the recall, as well as other ARB-class medication.
These medicines would be priced equally or lower during the interim period. Refunds will also be given to patients returning the affected medication.
Additionally, fees incurred for tests and additional consultations to assess suitability for alternative medication will be waived, said MOH.