Veterinarians have been unable to order the heartworm preventatives Interceptor or Sentinel because of the facility shutdown.

Other affected drugs include Milbemite and Deramaxx. Atopica, Capstar and Adequan are not made at the facility and are therefore not an issue.

Novartis, however, has not released any official news releases or statements regarding the veterinary drug shortage, leaving veterinarians wondering when the drugs will make it back on the market again.

Veterinarians are saying they did not receive a letter or even a phone call from their Novartis representatives.

It is unclear whether Novartis sent a Dear Doctor letter to its veterinary consumers; when Trends Today asked for a copy of a Dear Doctor letter, a Novartis spokesman replied that he did not have any additional information to share at this time.

In a related event, the Novartis Consumer Health division announced Jan. 8, 2012 that it was voluntarily recalling all lots of select bottles of Excedrin and NoDoz products with expiration dates of Dec. 20, 2014 or earlier, as well as Bufferin and Gas-X Prevention products with expiration dates of Dec. 20, 2013 or earlier. Novartis says the products may contain stray tablets, capsules or caplets from other Novartis drugs.

U.S. Food and Drug Administration (FDA) officials warned that some of Novartis’ over-the-counter pills may have been packaged with powerful prescription painkillers manufactured at the same facility. The painkillers, sold by Endo Pharmaceuticals, may include Percocet, Endocet, Opana and Zydone.

According to Novartis, the Consumer Health recall came following consumer complaints of chipped and broken pills and inconsistent bottle packaging, though Novartis says no adverse events have been reported. Consumers who purchased the recalled products are advised to discontinue use and return them to Novartis Consumer Health for a full refund.

The FDA has not issued a recall of the Novartis consumer drugs.

Novartis has announced it will gradually resume operations at the Nebraska site following implementation of planned improvements and in agreement with the FDA, but gave no date for operation to resume.

Though the Veterinary Information Network (VIN) reported in December that Novartis would resume production of Interceptor in January, a Novartis spokesman says the situation had not changed, and that they did not have additional information to share at this time.

Novartis has been in hot water with the FDA the last few months for several uncorrected violations at its Sandoz plants.

Sandoz is the generic pharmaceuticals division of Novartis.

Novartis received a warning letter from the FDA dated Nov. 18, 2011, warning Novartis CEO Joseph Jimenez of violations at its Sandoz manufacturing facilities in Broomfield, Colo., Wilson, North Carolina and in Boucherville, Quebec, Canada.

Many of the violations the FDA cited were repeat offenses from as far back as 2008 that Novartis had failed to properly correct. Citations included inadequate cleaning of equipment, failure to follow procedures designed to prevent microbiological contamination of drugs, and lack of investigation of failed products.

Interceptor is an orally administered tablet intended to control worms; Sentinel is also an oral flavored tablet designed to help control fleas.

Veterinarians attempting to order non-Novartis heartworm preventatives as recently as Jan. 10, 2012 are finding that many non-Novartis drugs are backordered as a result of the Novartis shortage. Ordering representatives are blaming backorders for non-Novartis heartworm preventatives on the Novartis issue, saying that the shortage is increasing demand for other products.

Merial is responding to the Interceptor shortage with assurances that its product, Heartgard Plus, continues to be available to veterinarians.

"In light of recent news that Novartis has temporarily suspended production of Interceptor, Merial is reassuring its veterinary customers of the continued availability of Heartgard Plus (ivermectin/pyrantel)," Merial said in a news release.

"Heartworm products are important preventives that must be given year-around to prevent heartworm disease in dogs and cats," Vangie Williams, marketing director for Heartgard in the United States said in the release. "So we want to let veterinarians know that this event has nothing to do with Heartgard Plus, which remains in good supply."

Trends Today will continue to update this story as more information becomes available.