A website promoting the pet parasiticide ProMeris proclaims “Party time’s over!” The message, directed at fleas and ticks, now applies to ProMeris itself.

Pfizer has announced that it plans to discontinue the manufacture and sale of the flea and tick control product for dogs and cats effective Sept. 20.

In a statement supplied by Pfizer via e-mail, Jim Brick, director and team leader of U.S. Marketing for Pfizer Animal Health said:

“After significant review and evaluation of the strategic fit into the Pfizer Animal Health portfolio, we have made the decision to discontinue the manufacture and sale of ProMeris flea and tick control for dogs and cats. We notified our current customers of this decision in early April and will continue to fill their orders until September 20, 2011, or while supplies last. We look forward to continuing to meet the needs of our customers with our evolving parasiticide portfolio.”

Pfizer acquired ProMeris among other products when it purchased Fort Dodge Animal Health as part of a $68-billion buyout of rival drug-maker Wyeth in 2009.

Wil Gwin, director of the Veterinary Teaching Hospital Pharmacy at Purdue University, said Pfizer’s decision to drop ProMeris isn’t surprising given the fact that it already has another topical parasiticide in its portfolio — Revolution, which works against heartworm as well as fleas, ticks and mites.

“There are a lot of products out there, a lot of ‘me, too’ products,” Gwin said. “Revolution is widely recognized as a proven seller. ProMeris is a (relatively) new product; it was supposed to be the newer, better ‘me, too’ product and it just never took off. At least in our experience, we never really saw a lot of demand for it.”

Pfizer’s announcement about ProMeris follows the recent publication of research that linked the development of a skin condition in dogs with use of the product. The study, “Metaflumizone-amitraz (Promeris)-associated pustular acantholytic dermatitis in 22 dogs: evidence suggests contact drug-trigger pemphigus foliaceus,” was conducted by investigators at the North Carolina State University College of Veterinary Medicine and published March 21 in the journal Veterinary Dermatology.

Joseph Donner, a contract communications specialist for Pfizer, suggested that the timing of the company’s decision to discontinue ProMeris was coincidental, not a result of the study findings. “I have not read the study; I know it exists,” he said in a telephone interview. “Definitely some DVMs are reading the report around here.”

Another possible side effect of ProMeris is potentially dangerous interaction with antidepressants such as fluoxetine (brand name Prozac) and doxepin, due to the action of amitraz — an active ingredient in ProMeris — as a monoamine oxidase (MAO) inhibitor, according to Purdue's Gwin.

MAO inhibitors suppress production of an enzyme necessary for proper metabolism of certain other drugs and foods.

Because of the potential for adverse effects, Gwin questioned the wisdom of continuing to sell ProMeris for several more months. “There’s still the potential for some harm to be done unintentionally through drug interaction,” he said.

However, some veterinarians expressed disappointment about losing the product. On a message board of the Veterinary Information Network, an online professional community, practitioners lauded ProMeris as being particularly effective against demodex, a mite that causes a type of mange.