Oxymorphone

What is this medication for?

• Sedative/restraining agent, analgesic (moderate-severe pain), preanesthetic — the cardiovascularly stable opioid choice

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.

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

• Constipation (↓stomach/intestinal motility) (Class)
• Dysphoria/excitement without a tranquilizer on board (Feline pattern)
• Panting (dogs) (Common)

Worth a phone call to your veterinarian

• Any new symptom that worries you.

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

• Respiratory depression, unusually slow heart rate (Class effects (usually acceptable ranges))

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

• has or has had: Hypersensitivity; toxin-diarrhea; extreme caution: respiratory disease
• has or has had: Hypothyroidism, acute uremia, Addison's, geriatric/debilitated, head trauma/↑ICP, acute abdomen

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Acepromazine/tranquilizers
  • Other CNS depressants
  • Naloxone/naltrexone
  • MAOIs

Storage and handling

C-II controlled; availability + expense are the practical limits.

Good to know

• The hemodynamically fragile patient's opioid: minimal histamine + minimal CV impact — where morphine's histamine would be unwelcome (shock, cardiac disease).
• Cats: pair with a sedative (acepromazine/midazolam/dexmedetomidine) — solo oxymorphone invites dysphoria.
• Availability/expense (C-II, marketing-era quirks) more than pharmacology limits its use — know it as the "clean" alternative when hydromorphone is unavailable.