Poisonous Human Medications for Cats and Dogs


Your medicine cabinet is likely full of pills, capsules, and syrups that could be extremely harmful to your pets. One of the main causes of poisoning of small animals like cats and dogs is exposure to drugs intended for human use.

While some human medications might be safe for cats and dogs, many are not and it’s crucial that human medications are only administered to cats and dogs under veterinary direction to ensure the medication and dosage is pet friendly.

Keep reading to find out what medications are toxic to pets, some common symptoms of drug poisoning and what to do if you suspect accidental ingestion.

1. NSAIDs (e.g. Advil, Aleve, Motrin, Aspirin, and more)

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are the most commonly ingested medications, likely due to how often we humans use these pain relievers. A mere one or two pills can cause serious harm to a cat or dog. Depending on the size of the pet and how much medication is ingested, it could result in stomach and intestinal ulcers, neurological changes, or even kidney failure.

2. Acetaminophen (e.g. Tylenol)

Acetaminophen is another common medication in many households. These pain meds are especially harmful to cats, resulting in red blood cell damage. Ingestion of Tylenol by dogs can lead to liver failure and red blood cell damage even when moderate doses are ingested.

3. Antidepressants (e.g. Effexor, Cymbalta, Prozac, Lexapro)

Human antidepressants are used occasionally in pets, but should only be given under strict veterinary supervision. Overdoses of these medications can lead to serious neurological problems, an elevated heart rate, blood pressure and body temperature. Cats appear particularly drawn to Effexor and often eat the entire pill due to its palatable taste. Just one of these pills can cause serious poisoning.

4. ADD/ADHD medications (e.g. Concerta, Adderall, Ritalin)

The potent stimulants in attention deficit disorder and attention deficit hyperactivity disorder medications can cause life-threatening tremors, seizures, elevated body temperatures and heart issues. A small dosage can do big damage.

5. Benzodiazepines and sleep aids (e.g. Xanax, Klonopin, Ambien, Lunesta)

While humans generally experience reduced anxiety and improved sleep while on benzodiazepines, they may have the opposite effect on pets. Dogs may experience agitation, severe lethargy, incoordination and slowed breathing. Some benzodiazepines can cause liver damage if ingested by cats.

6. Birth control (e.g. estrogen, estradiol, progesterone)

When a pet gets into your medication, it can be hard to determine how much they ingested. Large doses of estrogen and estradiol can cause bone marrow suppression. Female pets that are intact are also at increased risk of side effects from estrogen poisoning.

7. ACE Inhibitors (e.g. Zestril, Altace)

Ingestion of ACE Inhibitors can cause low blood pressure, dizziness and weakness. The risk of illness depends on the size of the pet, and the dose ingested.

8. Beta-blockers (e.g. Tenormin, Toprol, Coreg)

Small doses of beta-blockers can lead to life-threateningly low blood pressure and a very slow heart rate.

9. Thyroid hormones (e.g. Armour desiccated thyroid, Synthroid)

Many pets, especially dogs are regularly treated for an underactive thyroid. Similar drugs are used in both humans and dogs. While small doses may not be harmful, overdoses in cats and dogs can cause hypertension, muscle tremors, nervousness, panting, a rapid heart rate and aggression.

10. Cholesterol lowering agents (e.g. Lipitor, Zocor, Crestor)

Ingestion of these medications by pets may cause vomiting or diarrhea acutely, and serious side effects can result from long-term exposure.

11. Medicinal Cannabis

Not many people know that the THC in cannabis is toxic to dogs and cats. If your suspect your pet ingested a small amount of THC the symptoms include sedation, low heart rate, urine dribbling and difficulty standing or walking. If your pet ate a high concentration of THC, serious symptoms could occur, such as vomiting, exaggerated response to stimuli (such as noise or light), and in rare cases, seizures and coma.

12. Allergy Pills (Benadryl, Claritin, Zyrtec)

Allergy pills can be safe for cats and dogs depending on the dosage. Your vet can give you the best prescription to fight your pet’s allergies as there are medications made for their immune and digestive systems. Large doses of allergy pills may cause your pet to be agitated and restless, they may have an abnormal heart rate or blood pressure and they may experience vomiting, seizures and sometimes death.

Learn more about the signs of pet poisoning and how to pet-proof your medicine cabinet

A pile of pill as a pomeranian dog sits in the background

What To Do If Your Pet Licked a Pill

Licking a pill could be as bad as swallowing it depending on what it is. The best bet is to find out what pill your pet licked and either call your veterinarian or the Pet Poison Helpline for advice.

What To Do If Your Pet Ingested a Human Medication

Depending on the drug and the dose, symptoms might start minutes or hours after ingestion. If you suspect your pet ingested a human medication, please call your veterinarian or the Pet Poison Helpline as soon as possible.

If you have coverage with Pets Plus Us, your call is free as part of your Blue Ribbon Benefits*. Refer to the user guide for the phone number or call us at 1-800-364-8422. 

If you don’t have Pets Plus Us pet insurance coverage, you can contact the Pet Poison Helpline at 1-800-213-6680 with any questions or concerns. Please be aware there is a $85.00USD/per case fee but it may save your pet’s life!  

Interested in Blue Ribbon Benefits? Get a free quote for Pets Plus Us pet insurance today!


Pet Poison Helpline, an animal poison control center based out of Minneapolis, is available 24 hours, seven days a week for pet owners and veterinary professionals that require assistance treating a potentially poisoned pet. The staff provides treatment advice for poisoning cases of all species, including dogs, cats, birds, small mammals, large animals and exotic species. As the most cost-effective option for animal poison control care, Pet Poison Helpline’s fee of $85.00 USD** per incident includes follow-up consultations for the duration of the poison case. Pet Poison Helpline is available in North America by calling 800-213-6680. Additional information can be found online at www.petpoisonhelpline.com

*Blue Ribbon Benefits is not available in Quebec
**Price is subject to change