Swiss pharmaceutical company Novartis issued a recall of Excedrin, Bufferin, NoDoz and Gas-X on Sunday, citing concerns that some bottles of the over-the-counter medications contain tablets of other Novartis products — perhaps including the powerful prescription painkillers Percocet, Endocet, Opana and Zydone — or contain tablets that are broken or chipped.

The recalled lots include select bottle sizes of Excedrin and NoDoz with expiration dates of Dec. 20, 2014, or earlier and some bottle sizes of Bufferin and Gas-X with expiration dates of Dec. 20, 2013, or earlier. Complete information about the recalled lots is available on the Novartis website.

"Mixing of different products in the same bottle could result in consumers taking the incorrect product and receiving a higher or lower strength than intended or receiving an unintended ingredient. This could potentially result in overdose, interaction with other medications a consumer may be taking, or an allergic reaction if the consumer is allergic to the unintended ingredient," Novartis reported in a statement posted on the U.S. Food and Drug Administration website.

As of Sunday, the company did not know of any adverse effects associated with taking incorrect or broken pills. Novartis halted operations at and shipments from the Lincoln, Neb., facility where the mixup apparently occured and is working with distributors to help customers return the products.

According to the Associated Press, the Nebraska plant was cited for "dozens of quality control problems" last summer.

Endo Pharmaceuticals, which sells the prescription painkillers involved, warned Monday that some of the drugs might be in short supply for some time because of the plant closure. Chief Operating Officer Julie McHugh said that Endo would ask doctors not to start new patients on one of the drugs, Opana ER, so that patients who were already taking the drug could continue to get the medication they need.