Introduction

Name

• Trazodone hydrochloride. 

Class of drug

• Phenylpiperazine antidepressant. 
• Serotonin (5-HT2A) Antagonist/Reuptake Inhibitor.

Description

Chemical name

• Trazodone hydrochloride. 

Molecular formula

• C19H22ClN5O.HCl 

Molecular weight

• 408.32 

Physical properties

• White, odorless powder. 
• Soluble in water. 

Storage requirements

• Store at room temperature (15-25°C). 
• Store away from heat, light, and moisture. 

Uses

Indications

• Used, in conjunction with behavioral management, for control of anxiety in cats: 
  • Separation anxiety. 
  • Noise phobias, eg fireworks, thunderstorms. 
  • Fear aggression Aggression: fear. 
  • Resource guarding. 
  • Generalized anxiety. 
  • Specific event anxiety, eg visiting veterinarian or traveling or boarding Reducing stress (visits to practice). 
• Post-surgery to facilitate tolerance of confinement. 

Administration

Pharmacokinetics

Precautions

Interactions

With other drugs

• MAO inhibitors, eg selegiline Selegiline or amitraz Amitraz (increase risk of serotonin syndrome). 
• Opioids, eg fentanyl and tramadol (increase risk of serotonin syndrome). 
• Increases sedative effect of hypnotics, anxiolytics, antihistamines, and sedatives. 
• Drugs that affect coagulation, eg NSAIDs, aspirin, warfarin or other anti-coagulants increase risk of bleeding). 
• Trazodone increases plasma levels of digoxin and phenytoin. 
• Increased plasma concentrations of trazadone seen with antifungals such as itraconazole and ketoconazole. 
• Cyproheptadine Cyproheptadine may reverse the effects of trazodone.

With diagnostic tests

• None noted.

Adverse Reactions

Further Reading

Publications

Refereed Papers

• Recent references from PubMed and VetMedResource.
• Erickson A, Harbin K, MacPherson J, Rundle K & Overall K L (2021) A review of pre-appointment medications to reduce fear and anxiety in dogs and cats at veterinary visits. Can Vet J 62(9),  952-960 PubMed. 
• Gilbert-Gregory S E, Stull J W, Rice M R & Meghan E. Herron M E (2016) Effects of trazodone on behavioral signs of stress in hospitalized dogs. JAVMA 249(11), 1281-1291 PubMed; vet.osu.edu/vmc/sites/default/files/images/Trazodone%20Paper%20JAVMA2016.pdf.
• Gruen M E, Roe S C, Griffith E, Hamilton A & Sherman B L (2014) The Use of Trazodone to Facilitate Post-Surgical Confinement in Dogs. J Am Vet Med Assoc 245(3), 296-30 PubMed. 

Organisation(s)

• National Office of Animal Health (NOAH) Compendium of Data Sheets for Animal Medicines. Website: www.noahcompendium.co.uk.