Antidepressant Poisoning in Cats

Cats are notoriously curious, and they’re known to get into things you may have thought were secure, like pill organizers, bottles, and even medicine cabinets. While they can be resistant to taking their own medications, felines seem to have an affinity for ingesting human antidepressants. 

The SSRI antidepressant venlafaxine, also known as Effexor, is especially appealing to cats, but other SSRIs can be poisonous as well. Tricyclic antidepressants, which comprise another class of these toxic medications, include amitriptyline, clomipramine, and nortriptyline with brand names like Elavil and Levate. Several other types of dangerous antidepressants such as norepinephrine inhibitors may be toxic as well.

Any accidental ingestion of an antidepressant is an emergency, and a veterinarian visit as soon as the poisoning is suspected or known is essential to the cat's treatment and recovery. 

In cats, signs of antidepressant poisoning appear primarily in the central nervous, cardiovascular, and gastrointestinal systems. Symptoms may appear from one to two hours, or as many as six to eight hours after ingestion, and may last 24 to 48 hours or longer. 

There are many potential symptoms of antidepressant poisoning, which can include:

• Dilated pupils
• Rapid abnormal eye movement
• Agitation and vocalization
• Rapid breathing
• Increased salivation
• Decreased urination
• Bluish skin and mucous membranes
• Loss of appetite
• Constipation
• Vomiting
• Lethargy 
• Loss of balance or coordination
• Racing heart or irregular heartbeat
• High blood pressure 
• Fever
• Tremors
• Seizures
• Shock 
• Coma
• A rapid decline that may end in death

Poisoning occurs in cats that have ingested antidepressant medication made for human consumption. It will most often occur as a result of:

• Antidepressant tablets being dropped, left out unattended or within reach of cats
• Bottles of antidepressants being left open
• Administered by pet parents to their cat when mistaking them for the cat's medicine

Identifying antidepressant poisoning can be tricky if pet parents don't actually see their cat eating the medication. If you witness your cat ingesting these drugs, or if you notice symptoms of a potential poisoning, the first and most urgent step is to get your cat to a veterinary clinic as soon as possible. If it's after regular clinic hours, find an emergency clinic ASAP. 

If you suspect your cat ate your medication, take along the labeled container the medication was in if possible, and be prepared to tell the vet how long ago the incident may have happened, and any symptoms you’ve observed. Also be sure to report any medical conditions your cat has, or any other medications they may be currently taking.

If you know what caused the poisoning, the vet may decide to initiate treatment right away. If the symptoms are a mystery, the vet will do a physical exam, noting the signs they can see and feel. They will likely draw some blood for analysis, but they may not wait for results before initiating treatment, as a few minutes’ delay can change the outcome of this emergent condition.

Treatment of antidepressant poisoning in cats aims to rid the feline of the toxins inside their body and to support the patient until symptoms abate and the cat recovers. In some cases, this may take 24 to 48 hours or longer, during which the cat will be kept at the hospital.

Ridding the body of the toxin

Decontamination consists of gastric lavage in which the stomach contents are flushed, followed by the administration of activated charcoal every three hours until symptoms have abated. Both treatments are only mildly invasive and carry little risk. The activated charcoal “soaks up” any circulating toxins remaining in the blood.

Supportive medical care

Supportive medical care will include intravenous fluid solutions to flush out toxins and to ensure the cat is well hydrated. In addition, maintaining an airway with an endotracheal tube, along with oxygen treatment, may be needed. The heart’s rate and rhythm will be monitored with an EKG, and measures to cool the cat’s body temperature, like cool compresses placed on the cat’s pulse points, may be initiated.  Blood pressure will be watched closely as well.

Medications

Medications to control symptoms like seizures and vomiting will be given as needed. In addition, an antihistamine will work as a mild sedative for the reduction of agitation.

In the case of tricyclic antidepressant poisoning, sodium bicarbonate may be given to lower the high acidity of the blood caused by kidney damage and dehydration. Other medications may include acepromazine (for agitation and tremors), cyproheptadine (an antihistamine), beta-blockers (given to reduce blood pressure), and methocarbamol (for muscle relaxation). 

The risk of these treatments largely centers on their timeliness, as a delay can significantly and negatively impact the outcome.

Recovery is dependent on the effectiveness of the treatment and the amount of time between ingestion and treatment. If accidental ingestion is caught quickly, cats often make a full recovery. Underlying kidney, liver, or cardiac disease, however, may lengthen recovery time. Cats who have been treated for antidepressant poisoning should have follow-up visits with their vet, who will monitor them for any long-term problems. 

The most important step to prevent accidental poisoning by antidepressants is to safeguard them, and all medications, so your cat can’t access them. Felines are very creative when it comes to satisfying their curiosity, and their humans must be at least one step ahead of them. Closed and locked cabinets and drawers are the most secure places to keep dangerous meds out of your feline’s paws.

Antidepressant poisoning in cats can be expensive to treat. If you suspect your cat is at risk of developing antidepressant poisoning, start searching for pet insurance today. Wag! Wellness lets pet parents compare insurance plans from leading companies like PetPlan and Embrace. Find the “paw-fect” plan for your pet in just a few clicks!

Average cost of treatment: $200 - $15,000