Cat Aggression Medication: Dosage and Side Effects – Relievet

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Cat Aggression Medication: Dosage and Side Effects

Jason Jones, MBA - June 21st, 2022

Cat Aggression Medication: Dosage and Side Effects

If you are considering medication for your cat, the aggression is most likely out of control. You have probably tried everything from behavior training to pheromones. You will do anything to bring back balance to your home and do not even want to consider giving up your furry friend.

But is cat aggression medication the answer?

This blog discusses medicines for aggressive cats. Of course, answering the crucial questions like what it does, how to use them, and their side effects.

Table Of Contents

  • Benzodiazepines for Cats 
  • Benzodiazepine Side Effects in Cats 
  • Benzodiazepine Toxicity in Cats
  • Lethal Dose of Benzodiazepine 
  • Monoamine Oxidase Inhibitors (MAOI) for Cats 
  • Monoamine Oxidase Inhibitors Side Effects in Cats 
  • Monoamine Oxidase Inhibitors Toxicity 
  • Lethal Dose of MAOI
  • Tricyclic Antidepressants (TCAs) for Cats 
  • Tricyclic Antidepressants Side Effects in Cats 
  • Tricyclic Antidepressants Toxicity
  • Lethal Dose of TCAs
  • Selective Serotonin Reuptake Inhibitors (SSRIs) for Cats   
  • Selective Serotonin Reuptake Inhibitors Side Effects for Cats  
  • Selective Serotonin Reuptake Inhibitors Toxicity 
  • Lethal Dose of SSRIs
  • Natural Aggression Remedies Cats
  • Conclusion 

Benzodiazepines for Cats 

Benzodiazepines (BZs) are the last resort for your cat because they have very powerful effects. They can help slow your cat's brain and central nervous system activity. They start working right away, so they can help with fear or aggression in a few hours. Benzodiazepine works by increasing chemicals in the brain, which block specific unwanted brain and body signals. The most popular Benzodiazepine for cats is Diazepam. Vets write Diazepam prescriptions for cats, dogs, goats, horses, and reptiles. 

Benzodiazepine Side Effects in Cats 

The most common side effect of Benzodiazepines may be in uncontrolled movement. Drowsiness, clumsiness, confusion, increased appetite, sleepiness, and weakness, are also included, with severe side effects being cardiovascular and respiratory depression.

Below is an in-depth table of Benzodiazepines, dosages, and side effects.

MedicineDosageCommon Side EffectsSevere Side Effects
Alprazolam (Xanax)0.125-0.25 mg per cat, every 8 to 24 hoursClumsiness, Diarrhea, Gas, Increased Appetite, Sedation, VomitingBreathing Problems, Facial Swelling, Hives, Seizure, Sudden Diarrhea
Clonazepam (Klonopin, Rivotril)0.05–0.2 mg/kg, one to three times/dayDrooling, Incoordination, Excitement, Sleepiness Sudden Liver Damage (may appear as diarrhea, yellowing of the skin, eyes, or gums, lack of appetite)
Diazepam (Valium, Ducene, Antenex)0.2–1 mg/kg, three times a day or as neededAggression, Agitation, Drooling, Increased Appetite, Incoordination, Weakness, Sleepiness hepatic necrosis, Lack of Appetite, Severe Lethargy, Steady Vomiting, Yellowing of the Skin Gums, and Eyes
Lorazepam (Ativan)0.025–0.08 mg/kg, one to two times/dayAggressive Behavior, Anxiety, Drooling, Increased Appetite, Increased Activity, SleepinessDepression, Lack of Appetite, Yellowing of the Skin, Gums, or Eyes

Benzodiazepine Toxicity in Cats

These are the overdose signs to watch for if your cat consumes a toxic amount of benzodiazepines; it may experience aggression, agitation, incoordination, nausea, severe sedation, and vomiting. 

Lethal Dose of Benzodiazepine 

A study found common signs of benzodiazepine poisoning in cats: agitation, Ataxia (nervous system issues), coma, muscle tremors, vomiting, and weakness. Cats that take a lethal dose of Benzodiazepines may suffer from airway collapse and need intubation. 

Monoamine Oxidase Inhibitors (MAOI) for Cats 

MAOIs may become dangerous because of the many drug and food interactions the drug carries. Foods with high levels of tyramine, an amino acid for blood pressure regulation, are very toxic when mixed with MAOIs. MAOIs are drugs that affect the chemical messages made from dopamine. Dopamine is involved in the brain's reward center and several body functions. MAOIs treat cognitive dysfunction in older cats, and studies have shown they can slow down brain aging. 

Monoamine Oxidase Inhibitors Side Effects in Cats 

Common side effects of MAOIs are associated with stomach issues like diarrhea, lack of appetite, and vomiting. However, sedation can also be a side effect. Severe side effects of MAOI for cats are deafness and high serotonin levels if taken in combination with certain foods and medications. Here is a deeper dive into Selegiline, including dosage and side effects.

MedicineDosageCommon Side EffectsSever Side Effects
Selegiline (Anipryl, Eldepryl, l-deprenyl, Selgian, Zelapar)0.5–1 mg/kg/day (in morning)Aggression, Confusion, Diarrhea, Drooling, Itching, TirednessDeafness, Panting

Monoamine Oxidase Inhibitors (MAOI) Toxicity 

The overdose signs from MAOIs include Ataxia, disorientation, hyperventilation, seizures, tremors, and unease. You must be aware of interactions between foods and drugs with MAOIs. Combining MAOIs and SSRIs can cause serotonin levels to become too high, which can be dangerous.

Lethal Dose of MAOI

The lethal dose of MAOIs for dogs and cats is not published, but the toxic human amount is reported to be 4-6 mg/kg. So, be very careful when giving your cat MAOIs. 

Tricyclic Antidepressants (TCAs) for Cats 

Tricyclic antidepressants (TCAs) treat compulsive behavior problems in cats. These can include excessive grooming, reacting negatively to other cats in the household, and anxiety problems. TCAs work by increasing the neurotransmitters norepinephrine and serotonin: both are involved in emotional reactions. 

Tricyclic Antidepressants Side Effects in Cats 

Tricyclic Antidepressants for cats' side effects include blurred vision, dry mouth, constipation, elevated liver enzymes, hives, low blood pressure, and weight gain or loss. Severe side effects are abnormal bleeding, coma, fever, irregular heartbeat (fast), and seizures.

Below are some TCAs, dosages, and common and severe side effects.

MedicinesDosageCommon Side EffectsSevere Side Effects
Amitriptylinoxide (Amioxid, Ambivalon, Equilibrin)0.5–2 mg/kg/dayConstipation, Drowsiness, Dry Mouth, Sedation, Urinary RetentionDecreased Blood Cell Counts, Diarrhea, Vomiting
Clomipramine (Anafranil/Clomicalm)0.25–1 mg/kg/dayConfusion, Diarrhea, Increased Thirst VomitingConvulsions, Elevated Liver Enzymes, Increased Heart Rate 
Doxepin (Silenor)0.5–1 mg/kg, one to two times/dayConstipation Decreased Appetite, Diarrhea, Dry Mouth, Straining to Urinate, VomitingAbnormal Bleeding, Abnormal Heartbeat, Collapse, Coma, Fever, Seizures 
Imipramine (Tofranil)0.5–1 mg/kg, one to two times/dayConstipation, Diarrhea, Dry Mouth, SleepinessBleeding, Collapse, Fast Heartbeat, Fever, Shaking, Seizures

Tricyclic Antidepressants Toxicity

Many pets have accidentally ingested TCAs. In four years, in the early '90s, over 450 cases of this happening were reported to the IAPIC. At least 7% of the animals that displayed toxicosis eventually died. Overdoses of TCAs negatively affect the cardiovascular, parasympathetic, and central nervous systems.

Lethal Dose of TCAs  

Animals that eat a lot of this drug (more than 15 mg/kg) may die within 1 or 2 hours if they do not get the proper treatment.

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Selective Serotonin Reuptake Inhibitors (SSRIs) for Cats 

SSRIs are drugs that are used to treat depression in people and pets. They work by increasing the level of serotonin in the brain. Side effects are generally mild.

Selective Serotonin Reuptake Inhibitors Side Effects for Cats 

SSRI side effects in cats may show in changes in behavior. Signs include anxiety, diarrhea, irritability, lack of appetite, and changes in sleep. Severe side effects of SSRIs are seizures, serotonin syndrome, and excessive vomiting.

Below is a deeper view of a few different types of SSRI medicines.

MedicinesDosageCommon Side EffectsSevere Side Effects
Prozac (Fluoxetine)0.5–1.5 mg/kg/dayDiarrhea, Hypersalivation, Incoordination, Panting, Shaking, VomitingAggression, Behavior Changes, Excessive Vomiting, Seizures
Paroxetine (Paxil, Brisdelle)0.25–1 mg/kg/dayConstipation, Diarrhea, Difficulty Urinating, Muscle Twitches, PantingAggressive Behavior, Over Excitement, Persistent Lack of Appetite
Sertraline (Zoloft)0.5–1.5 mg/kg/dayAgitation, Diarrhea, Dry Skin, Itchiness, VomitingAbnormal Blood Pressure, Aggression, Coma, High Body Temperature, Seizures

Selective Serotonin Reuptake Inhibitors Toxicity 

Some common symptoms of SSRI toxicity are intestinal problems like diarrhea, excessive drooling, and vomiting. There can also be problems with the Central Nervous System like tremors, seizures, and a high body temperature.

Lethal Dose of SSRIs

If your cat takes a lethal dose of SSRIs, the effects may be Ataxia, high blood pressure, seizures, serotonin syndrome, and death. The lethal dose of Fluoxetine is 50mg/kg. A cat would have to take a ridiculous amount of SSRIs to have a lethal reaction. 

Natural Aggression Remedies Cats

You are probably looking at all the side effects and wondering if there are natural alternatives. Fortunately, there are options you can choose that have fewer and milder side effects.  

  • Herbs – There are many different types of herbs. Some common forms are tinctures, dried flowers or leaves, essential oils, and teas. However, it is important to note that you should never use essential oils on cats because they can harm their liver. Some cat calming herbs are Catnip, Chamomile, Hops, and Valerian. 
  • Stop aggression at the Source – Through observation, patience, and practice, you now have a good idea of what is causing your cat's aggression. If your cat plays aggressively, you can redirect their attention to stuffed animals or toys. If your cats are not getting along, you can separate them. If fear aggression kicks in when noises or actions around the house startle or scare a cat, you can try to stop or lessen the impact those activities have on the cat. 
  • CBD for Cats - CBD may be helpful for cats because it can calm them down, relieve stress and anxiety, and reduce pain and inflammation. Veterinarians and pet owners often consider CBD for cats because of its relative harmlessness. CBD may be the solution your cat needs to chill out.


There are many different types of antidepressants. They can all be dangerous or even deadly to your cat if too much is ingested. If you are looking for an alternative, it offers hope to you and your pet.

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