The antidepressant Venlafaxine(sold under the brand name Effexor) is a pharmaceutical success story; in a single year, U.S. doctors prescribed it more than 17 million times. It's not without controversy. As Medline Plus points out, it's among a group of antidepressants that were linked to suicidal behavior in children, teenagers and young adults.
But while that risk has been well reported, most people don't know that Venlafaxine is also uniquely dangerous to household pets. Especially cats. "Cats love to eat it," says Dr. Tina Wismer, medical director of the Animal Poison Control Center operated by the American Society for the Prevention of Cruelty to Animals (ASPCA). She speculates that it may be something about the way this particular antidepressant smells. "It's crazy when you think about how hard it is normally to give a cat a pill. But in this case they'll swallow multiple pills."
The subject of antidepressant loving cats - and the potentially lethal kidney damage that can result from that - came up when I was talking to Dr. Wismer about the poison control center's newly released list of the ten top ways that American pets are accidentally poisoned - at least based on calls to the Urbana, Illinois-based poison control center. The list was just released because this week (March 16-22) is National Poison Prevention Week.
As readers of this blog know, I occasionally write - or perhaps the better word is rant - about deliberate poisoning of pets. It's not a topic I love. The last one, called Your Neighborhood Pet Poisoner, was posted about a year ago. This is not a problem that has in anyway disappeared since that time. As an example, I refer you to this week's storyof the deliberate poisoning of more than 15 dogs in Topeka, Kansas or last month's taleof poisoned meatballs being placed on San Francisco sidewalks for the second time in eight months.
These are stories of awful people, at least to me, and they always lead me to dwell retribution. But, it's worth remembering that careless people poison a lot more pets. The animal poison control center recorded received almost 4,000 calls related to cats and dogs who'd swallowed antidepressants by accident. And if that doesn't sound like many to you - the calculation is that poison control centers respond to about 1-2 percent of all poisonings (both animal and human) as many people go directly to doctor, hospital or vet with their crisis. The total number of emergency calls was nearly 30,000.
Dr. Wismer says that prescription medicines are the top cause of household animal poisonings; they account for almost 20 percent of all calls. And as it turns out, antidepressants aren't the worst offender. That honor belongs to cardiac-related drugs, such as blood pressure medications. Last year they added up to more than 4,000 calls for help. This seems to be a trend: an older American population, more use of such medications, and more people standing close by their companion animals. Often the APCC has found, the dogs and cats swallow these pills when people accidentally drop them while taking their medication. "Especially dogs," says Dr. Wismer. "Dogs are gulpers." Her organization recommends that people with pets take their medicines over a sink so that if it a pill drops it doesn't fall on the floor. And it strongly recommends not leaving pills or small containers of that day's pills on a table or counter. Not only are cats attracted to Vinlafaxine but it appears that dogs are drawn to Vivance, a time-release stimulant used to treat Attention Deficit Hyperactivity Disorder ADHD).
"It causes dogs to become very, very agitated," she says. So does the prescription sleep-aid Ambien.
If you follow the animal poison control center list, the other top risks include over-the-counter painkillers like acetaminophen; pesticides (especially rodent poisons) used around the home and garden, fertilizers (which often include such attractive ingredients as bone meal, cocoa shells, and even dried blood), cleaning supplies, poisonous plants like lilies, which can cause kidney failure in cats, and foods, including onions, garlic, grapes, raisins, the substitute sugar xylitol, and chocolate. Chocolate contains a plant alkaloid called theobromine which is mildly stimulating to humans and dangerously overstimulating to dogs. As I've written before, it's a great example of species' differences in chemical response. On a similar note, Dr. Wismer notes also that opioid pharmaceuticals are often tolerated far better by dogs and cats than they are by humans.
That doesn't mean she advocates relaxing. "The most important thing is to try to keep medications away from pets and in the original bottle if possible," she says. The latter allows people at the poison control center or a local vet to know the specific dose and therefore its risks. "And know your vet's emergency number. Just in case."
Photo: Deborah Blum
