Anapen and Anapen Junior are drugs that are injected to provide adrenaline to counteract allergic reactions, such as those that can occur from eating nuts or a wasp sting.
However, AllergyCare, the British manufacturer of the products, said some of the “auto-injectors” used to administer the product could be defective.
As a result, they could fail to release the active pharmaceutical ingredient into the body or only partly because of a possible blockage in the needles.
Swissmedic, the Swiss agency for therapeutic products, issued a warning on Friday for users of Anapen to contact a doctor immediately.
Physicians can prescribe another product aimed at counteracting allergic reactions or determine whether the patient can wait until new versions of Anapen become available, the agency said.
AllergyCare said new versions of both Anapen and Anapen Junior will be on sale in early July.