By Neve Brissenden in Sydney

Sick customers who bought some cold and flu medications have been falsely assured their nasal congestion would be relieved, an Australian law firm alleges.

Lawyers at JGA Saddler have filed a class action on behalf of millions of customers, alleging they were misled by pharmaceutical giant Johnson & Johnson’s over-the-counter medications including Codral Day and Night, Sudafed PE and Benadryl PE.

The class action concerns tablets containing phenylephrine, a substance the US Food and Drug Administration (FDA) has declared ineffective as a nasal decongestant when taken in tablet form.

Johnson & Johnson replaced pseudoephedrine with phenylephrine when the former was taken off shelves over drug abuse concerns in 2006.

Brisbane ear, nose and throat specialist Jo-Lyn McKenzie said phenylephrine was not a decongestant.

“It’s unconscionable and deeply unethical for corporations to sell health-care products while knowing they don’t work,” Dr McKenzie said.

JGA Saddler director Rebecca Jancauskas said Johnson & Johnson must be held accountable.

“(It has) manufactured and marketed a medication that decades of evidence have shown doesn’t work as claimed, relying on outdated, fallible studies to sell the Australian public products that don’t do what they claim on the packet,” she said

“Australians have trusted these products to work as advertised and wouldn’t have bought them if they realised they were ineffective at treating congestion.”

The law firm is urging other affected customers to get in touch and become part of the class action.

Johnson & Johnson has been contacted for comment.