TRENTON, N.J. (AP) — Johnson & Johnson is again recalling a prescription drug because of an odd musty odor likely caused by a chemical on shipping pallets.

J&J said Wednesday that it's recalling five lots of its HIV medicine Prezista at the wholesale and pharmacy level in five foreign countries: Austria, Canada, Germany, Ireland and the United Kingdom. Fewer than 2,000 bottles of the pills are believed to still be in the marketplace in those countries.

Patients should not stop taking the medication, according to Johnson & Johnson, which will replace any affected bottles. No cases of serious patient harm have been reported, but four consumer reports of the musty, moldy odor led to the recall.

Johnson & Johnson's Janssen-Cilag International N.V. unit will replace bottles from the affected lots, which include only the higher doses of Prezista. In the U.K., lots of the 400 milligram dose are being recalled; in the other countries, 400 and 600 milligram bottles are being recalled. Patients can call the company toll-free at 0800-032-3013.

J&J, based in New Brunswick, N.J., has announced about two dozen recalls since September 2009, involving well over 300 million bottles of nonprescription medicines, plus some prescription drugs, contact lenses and hip replacements. The reasons have ranged from nauseating odors and incorrect level of active ingredient to contaminants in medicines and uncomfortable hip replacements requiring repeat surgery.

J&J's investigation of the Prezista complaints concluded the odor probably is due to trace amounts of the chemical TBA, or tribromoanisole, on bottles that came from a common supplier. TBA is a byproduct of a chemical preservative sometimes used on wooden shipping pallets.

The chemical has been blamed for numerous recalls by Johnson & Johnson and a couple of other drugmakers over more than a year. J&J said it started taking steps in January 2010 to get suppliers to stop using pallets with chemically treated wood, and it's working with other drugmakers to determine how the chemical is getting into the supply chain.

The continuing recalls have hurt J&J's revenue, profit and stock price, as well as its once-stellar reputation. But in midday trading Wednesday, J&J shares rose 67 cents, or 1 percent, at $66.43.