What is Effexor Poisoning?
Effexor is a type of antidepressant known as a selective norepinephrine reuptake inhibitor (SNRI). This type of medication blocks the reabsorption of serotonin and norepinephrine in the brain and overdoses can lead to a disorder known as serotonin syndrome. This syndrome is characterized by altered mental status and can be a life-threatening disorder when left untreated. Antidepressants can be effective for some canines in situations such as severe anxiety or cognitive dysfunction, but even therapeutic doses can result in moderate signs of toxicity.
Effexor is an antidepressant that blocks the reabsorption of serotonin and norepinephrine in the brain. Overdoses can lead to a disorder known as serotonin syndrome.
Symptoms of Effexor Poisoning in Dogs
Signs and symptoms in dogs that have taken the extended release version of Effexor (Effexor XR) may have a delayed onset and may persist for up to 72 hours.
- Abdominal pain
- Aggression
- Agitation
- Anxiety
- Confusion
- Dilated pupils
- Diarrhea
- Drooling
- Elevated heart rate
- Elevated temperature
- Lethargy
- Panting
- Sedation
- Seizures
- Shivering
- Tremors
- Twitching
- Vocalizations
- Vomiting
Pain medications taken in conjunction with an SNRI like Effexor can cause your pet to bleed or bruise easily.
Types
SNRI medications may occasionally be prescribed for a canine with severe anxiety or compulsive type disorders, although it can be 1-4 weeks before full effects are seen.
SNRI medications and their brand names:
- Desvenlafaxine (Pristiq)
- Duloxetine (Cymbalta)
- Levomilnacipran (Fetzima)
- Milnacipran (Savella)
- Venlafaxine (Effexor)
- Venlafaxine XR (Effexor XR)
Other types of antidepressants that can cause serotonin syndrome:
- SSRI - Selective Serotonin Reuptake Inhibitor, like SNRI medications, many of these medications can be used to treat aggression and anxiety in some dogs
- Tricyclic Antidepressants - These antidepressants regulate the brain chemicals and prevent chemical imbalances and can be indicated with extreme noise or separation anxieties in canines
- Monoamine Oxidase Inhibitors (MAOIs) - This type of antidepressant represses monoamine oxidase from removing serotonin or dopamine from the brain. These may be used to treat cognitive dysfunction or adrenal gland disorders in dogs
Causes of Effexor Poisoning in Dogs
SNRI medications like Effexor are designed to change behavior by blocking the reabsorption of serotonin and norepinephrine in the brain. In some cases, this can cause an overabundance of serotonin in the brain and the resultant overstimulation of the receptors in the brain can cause a cascade of symptoms related to the disruption of the central nervous system (CNS). This is known as serotonin syndrome, and can occur either from an overdose of an antidepressant medication or a combined effect of prescribed anti-depressants and foods or supplements that can increase the levels of serotonin in the brain.
SAMe (S-adenosylmethionine), a supplement commonly used for mental, liver, and joint support, and is known to increase the levels of serotonin and should not be given in conjunction with an SNRI or SSRI antidepressant. 5HTP (5-hydroxytryptophan) is an amino acid that is used by the body to manufacture serotonin, and supplementation with 5HTP while taking antidepressants can cause a toxic increase in serotonin levels. Foods high in tryptophan and Vitamin B6, B9, and D are also known to stimulate serotonin production, as is magnesium.
Diagnosis of Effexor Poisoning in Dogs
Your veterinarian will need to get your pet’s full history from you, including any prescriptions or supplements that you give your dog. If you witnessed the ingestion of the antidepressant you should give your veterinarian as much information about amounts and dosages that you can, and bring in any packaging from the medication as well. A chemistry profile and complete blood count will be completed as well during the general physical examination. Although there is no direct test for serotonin syndrome itself, the urine, stools, and vomitus testing may expose underlying diseases or toxins as well as the venlafaxine itself. If the stomach of the canine is pumped during the visit, any gastric contents will also be thoroughly analyzed. Neurological testing may also occur during the diagnostic appointment, in order to measure your pet’s reflexes and coordination. This may also be helpful in pinpointing the specific areas of the nervous system that have been affected.
Treatment of Effexor Poisoning in Dogs
Always contact your veterinarian immediately if you catch your pet consuming anything that they are not supposed to. In the case of Effexor and other antidepressants your veterinarian may instruct you on the proper way to cause your canine to vomit before traveling to the office if it was ingested within the last thirty minutes, to avoid any further absorption of toxic amounts into the bloodstream. If it has been longer than thirty minutes, gastric irrigation under general anesthesia may be performed at the veterinary office. This is done to remove as much of the medication from the digestive system as possible before it can be absorbed into the blood. Fluids and supportive treatment will also be given, including regulation of the body temperature, IV fluids for dehydration, and serotonin antagonists. Prognosis of serotonin syndrome is dependent on the amount eaten, the speed of initial diagnosis and treatment, and the size of the dog, but in most cases that are treated promptly, recovery is seen within twelve to eighteen hours from ingestion. If the medication taken was the extended release formula, recovery is still likely but it may take 48 to 72 hours to clear the system.
Recovery of Effexor Poisoning in Dogs
Patients that are in recovery from requiring anesthesia for a gastric lavage may have coordination difficulties when they first get home and are often quite disoriented. Ensuring that the recuperating patient has a calm and quiet environment with ample access to highly nutritional food and clean water to return home to will help speed recovery, and isolation from children and other pets is generally recommended until the anesthesia and the Effexor has fully cleared your companion’s system. It is important to ensure that your pet completes the full measure of any medications that were prescribed for management of the condition, and any other supplements should be discussed with your veterinarian to avoid negative interactions.
Effexor Poisoning Questions and Advice from Veterinary Professionals
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Please help!! I believe my dog ate a 150 mg venafalaxin. What do I do, she isn't acting overly odd but she does have some over vocalization and is very thirsty. Her pupils are huge, but in the sunlight they do get small. Please tellme what to do. help..
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My dog got into my brand new 90 day supply of venlafaxine. I have no idea how much she got but my parents don't seemed worried. Will she die from this? This just happened and I have yet to see her yet to know how she is.
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my 7 lb. pomeranian ate part of a effexor 75mg, this morning, acting normal , some powder was left behind including shell of capsule. Vet said call poison control, they charge $65.00 for advice, cannot believe that. Please help.
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we found a pill casing of a 75mg effexor xr capsule that my 7 lb pom picked up on the floor that i must haved droped last night before bedtime. we found it this morning it was not wet and some of the inside of the capsule was there what should we do
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Our dog Romeo whos is a full grown male boxer and he weighs about 75-80 pounds.one of my husbands effexor xr pills fell from the dreaser and he started to lick at it. From what i can tell all the little balls are still in the capsule, he may have ingeated 1/5 of it if that. They are 37.5 mg capsules. Should i be concerned? He shows no symptoms and its been 15 min still no unusual symptoms. Should i continue to monitor him and would tou say the best course of action is to keep him hydrated??? Worried doggy mom and dad...
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my dog ate one of my effexors what should I do?
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In any case of suspected poisoning, Veterinary attention is always important to ensure that the source of the poisoning is vomited out or pumped out of the stomach to prevent the medication reaching the blood supply. Symptoms of poisoning include (even at low levels) are vomiting, diarrhoea, lethargy, rapid heart rate, tremors, seizures, abdominal pain, change in behaviour and other neurological signs; these symptoms may have a delayed onset, due to the nature of the medication. Your Veterinarian would give supportive therapy by ensuring that Lou remains hydrated and any neurological symptoms are managed. Regards Dr Callum Turner DVM
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