Janssen-Cilag International, part of Johnson & Johnson (J&J) is working with regulatory authorities in five countries to address the trace amounts of 2,4,6-tribromoanisole (TBA) that were identified in five batches of the HIV–AIDS medicine Prezista (darunavir). The countries affected include the United Kingdom, Ireland, Germany, Austria, and Canada.

Janssen initiated discussions with regulatory authorities after receiving four consumer reports of an uncharacteristic musty or moldy odor. The company’s investigation determined that the odor was likely caused by trace amounts of TBA found in bottles sourced from a common supplier.

As discussions with regulatory authorities in each of the five countries continue, the company “is committed to recalling and replacing any affected bottles of product remaining in the marketplace,” according to a J&J press release. Janssen estimates that fewer than 2000 bottles have been affected in countries where recalls have been initiated. The action applies to 400- and 600-mg tablets of Prezista. In the UK, only 400-mg tablets of Prezista are affected.

The company and the European Medicines Agency agreed on a Class II recall at the wholesale and retail (i.e., pharmacy) level. Discussions with regulatory authorities in Canada are underway to determine the appropriate course of action. Janssen-Cilag said it does not expect a product shortage to result from the company’s actions to recall and replace affected product.

TBA is a byproduct of a chemical preservative sometimes applied to wood. The chemical is often used in the construction of pallets on which products are transported and stored. While not considered to be toxic, TBA can generate an offensive odor, and patients have reported temporary gastrointestinal symptoms, according to the J&J press release. TBA has caused no reported serious adverse events, according to the company.

In January 2010, Janssen instituted several actions to reduce the potential of TBA contamination, including requiring suppliers to verify that they do not use pallets made from chemically treated wood. An internal investigation is underway with suppliers to evaluate all potential sources of TBA. In addition, Janssen is working with peer companies to better understand how and where TBA is entering and affecting the supply chain.