Rockville, Md. — Reports of precipitate forming in opened or leaky bottles has led Merial to alter its directions to use Eqvalan Liquid for Horses (ivermectin).

Veterinarians now are instructed to use the bottle’s contents within four hours of opening it or discard what remains. The same goes for diluted product, the Food and Drug Administration’s Center for Veterinary Medicine (CVM) advises in an alert issued yesterday.

According to a “Dear Veterinarian” letter dated Sept. 8, Merial says claims of precipitate findings represent approximately 0.2 percent to 0.4 percent of manufactured units of Eqvalan Liquid for Horses. While Merial reports no evidence of adverse drug reactions, company officials want to “minimize any potential impact to veterinarians and their patients.”

Veterinarians are advised to examine the product before using it. Bottles with precipitate can be returned to the company by calling Merial Veterinary Technical Solutions at (888) 637-4251, option 3.

The company also is adding disposal instructions that remind veterinarians to not to flush or pour unused medication down toilet or sink drains, but mix unused medication with cat litter or sawdust before placing it a sealed container. From there, it can be trashed in a landfill or by incineration.

CVM also advises veterinarians to exam generic equivalents before use. If a precipitate is found, the manufacturer should be contacted.

Eqvalan Liquid for Horses is formulated for equine patients only. Use in any other species can cause severe adverse reactions, including fatalities in dogs, Merial says.