Three companies that sell herbal products with names similar to Prozac have been sued by Eli Lilly and Company in the last year for trademark infringement. The most recent suit was filed in U.S. District Court in Indianapolis against Natural Answers, the maker of Herbrozac.

The court granted Lilly’s motion for a preliminary injunction in January prohibiting Natural Answers and its founder, Brian Feinstein of Naples, Fla., from using the name "Herbrozac" on its herbal products, according to a statement from Eli Lilly. The defendants have appealed the injunction to the Seventh Circuit Court of Appeals.

The District Court agreed with Lilly that Herbrozac, a blend of St. John’s wort and several other herbs, sounded very similar to Prozac. The Court stated in its decision to grant a preliminary injunction that the "defendant intentionally selected the name Herbrozac. . .for the purpose of suggesting an association or affiliation between the products."

The court also stated, "Natural Answers chose a name similar to Prozac rather than other antidepressant drugs because Prozac is the most famous and best-selling antidepressant drug." Since 1988, doctors have prescribed the drug at least 240 million times for more than 17 million Americans. Its sales have exceeded more than $12 billion since 1988, according to the court opinion.

Herbrozac is part of a line of products called HERBSCRIPTIONS marketed by Natural Answers on its Web site <www.naturalanswers.com>. Other products include Herbalium, Vita-Agra, Climagra, Herbaspirin, and HerbenolPM.

"The chosen product names suggest the intended functions or benefits of brand-name drugs precisely because consumers are familiar with them," the court said.

Lilly filed a notice of opposition last year in response to Natural Answers’ application to register a trademark for Herbrozac, which is still pending. The maker of Tylenol PM, McNeil Pharmaceuticals, filed a notice of opposition to Natural Answer’s application to register HerbenolPM, according to the court’s opinion.

Lilly has sued two other herbal companies for trademark infringement. Christopher Enterprises agreed to settle in January and stop using the name ProTrac or any other name similar to Prozac. Lilly’s case against Streamline International, the maker of NuZac, is pending.