Pet Medication 101: Amitriptyline

1. Drug Name:

amitriptyline hydrochloride

2. Brand Names:

Elavil, Endep, Entrip

3. How Dispensed:

Prescription only

4. Forms:

10 mg, 15 mg, 25 mg, 50 mg, 75 mg, 100 mg, 150 mg amitriptyline hydrochloride film-coated tablets

Oral dose combination products containing chlordiazepoxide or perphenazine

5. Drug Type/Class:

Tricyclic antidepressant, adrenergic uptake inhibitor, nonnarcotic analgesic

6. Uses in Dogs and Cats:

Used in dogs, cats, and birds for treatment of certain behavioral disorders such as generalized or separation anxiety and spraying. Used for treatment of neuropathic pain in dogs and cats.

7. How it Works:

Amitriptyline blocks reuptake (absorption) of the hormones norepinephrine and serotonin. This allows these hormones to be at a higher level to stabilize mood and increase feelings of well-being.

8. Side Effects and/or Signs of Overdose:

Side effects include sedation, and rarely constipation and urinary retention. Occasionally dogs may become hyperexcitable and rarely develop seizures from amitriptyline. Cats may salivate excessively and have decreased appetite.

Signs of overdose include vomiting, diarrhea, restlessness, agitation, vocalization, seizures, loss of consciousness, increase in heart rate, muscle tremors, fasciculations, and can even lead to death.

9. Drug Interactions:

• Selective-serotonin reuptake inhibitors (fluoxetine)
• Thyroid medications
• Clonidine
• Cimetidine
• Ephedrine
• Mephentermine
• Cisapride
• Diazepam
• Monoamine oxidase inhibitors (selegiline, amitraz)
• Quinidine

10. Cautionary Statements:

• Amitriptyline should not be administered to pets with any of the following conditions:
  • Hyperthyroidism
  • seizure disorders
  • cardiac dysrhythmia
  • narrow-angle glaucoma
  • patients taking thyroid medication
• Patients experiencing problems with urinary retention or urine flow, which may include those with prostatic hypertrophy, should avoid the use of amitriptyline.
• Should not be used within two weeks of administering monoamine oxidase inhibitors (MAOIs) such as amitraz or selegiline.
• It may take several weeks to see clinical effects and behavioral improvement.

Read more:

Tips for Helping Your Dog with Separation Anxiety

Separation Anxiety in Cats

Feather Picking and Self-Mutilating Behaviors

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