Trazodone HCl

What is this medication for?

• Adjunctive anxiolytic (vet visits, separation anxiety, storms/noise phobia, travel); post-surgical activity restriction/calming
• Situational drowsiness (e.g., transport/handling anxiety)

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

• Faster onset than SSRIs/TCAs — useful as an as-needed/situational anxiolytic given ~1h before a known trigger event, unlike daily-dosed agents that need weeks to reach effect.
• Give with food to improve tolerability and reduce peak-level variability.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Sedation (dose-related, not always undesired) (Most common)
• Aggression, unusually fast heart rate (More likely if given into a vein — do not give into a vein to dogs)
• No significant adverse effects at 100 mg/cat in controlled study

Worth a phone call to your veterinarian

• Vomiting/gagging, ↑excitement, ↑appetite, colitis (rare) (Uncommon; ~80% of dogs in one study had no adverse effects)

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Trouble breathing, collapse, seizures, severe vomiting or diarrhea, facial swelling, or pale gums

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Hypersensitivity; concurrent MAO inhibitors
• has or has had: Severe cardiac disease, hepatic/renal impairment; do not administer into a vein to dogs

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • SSRIs (fluoxetine), TCAs (clomipramine), tramadol, MAO inhibitors (selegiline)
  • Azole antifungals (ketoconazole, fluconazole), macrolides (erythromycin)
  • Digoxin
  • NSAIDs, aspirin
  • Metoclopramide

Storage and handling

Store 20–25°C (excursions 15–30°C), airtight container, protect from light.

Good to know

• Faster onset than SSRIs/TCAs — useful as an as-needed/situational anxiolytic given ~1h before a known trigger event, unlike daily-dosed agents that need weeks to reach effect.
• Often combined with a daily serotonergic drug (SSRI/TCA) plus benzodiazepine for layered anxiety management — but stack serotonergic combinations cautiously given cumulative serotonin syndrome risk.
• Give with food to improve tolerability and reduce peak-level variability.