The WHO on Tuesday cited adverse effects in pediatric patients receiving the drug, and said that its product alert referred to a batch of substandard Methothrex (methotrexate), which had been identified in Yemen and Lebanon.

The drug, an immunosuppressant used to treat cancer and autoimmune diseases, is on the WHO model list of essential medicines.

“It is important to detect and remove this contaminated product from circulation to prevent harm to patients,” the WHO alert said.

The statement also called for “increased surveillance and diligence within the supply chains of countries and regions likely to be affected by this product.”

Lebanon’s health ministry on Wednesday issued an order banning the drug and took steps to stop its circulation in the country.

However, the ministry said that the drug was not registered in Lebanon and had been brought into the country by illegal means.

Lebanon’s failing economy and currency crisis are fueling a market for smuggled drugs and medicines, which authorities fear is a growing threat to public health.

The health ministry warned patients against buying drugs from unknown sources, and said that people should consult a list of registered medicines published on its website in order to ensure their safety and avoid the risk of using contaminated products.

Joe Salloum, head of the Lebanese Pharmacists Syndicate, said the latest batch of contaminated drugs were most likely smuggled into the country.

He described smuggling operations as “the deliberate killing of patients.”

Salloum said that smuggled drugs that are not registered with the health ministry are now circulating widely in the country.

“These drugs do not meet international standards and those allowing this to happen are deliberately killing patients. This is why we must speed up securing safe medicines for patients, and draw up a plan to directly support the patient to be able to buy the right medicines,” he said.

Bilal Abdullah, head of the parliamentary health committee, told Arab News: “The borders and ports lack controls. Dozens of medicines that enter are either expired or contaminated, and they are detected only when patients with serious side-effects are rushed to hospital.”

Referring to the product banned by Lebanese health authorities, Abdullah said: “There is a chain that begins with the smuggler, the distributor and the pharmacist who prescribes the drug as an alternative to a drug that contains the same medicinal substance.”

He said that organized crime gangs are involved in smuggling medicines. “These people have nothing to do with religions, politics or sects. All they care about is taking advantage of crises to accumulate illegal profits.”

Abdullah called for security and oversight agencies at all borders and ports to tighten procedures as a first step to countering the problem.

Fellow health committee member Fadi Alama told Arab News that the market for pharmaceuticals in Lebanon is difficult to control despite measures taken by the health ministry.

“The problem must be addressed as soon as possible, and the health ministry has a good monitoring system that can be used to withdraw these drugs from the market,” he said.