Procaine with Epinephrine
Also known as: Willcain
Your pet has received a local anesthetic to numb a specific area for a procedure. > **Important:** The area may remain numb for a few hours. Prevent your pet from chewing, scratching, or rubbing the numb area, as they could cause severe self-injury without feeling it. Monitor the injection site for any signs of excessive swelling, redness, or skin discoloration, and contact your veterinarian if you notice any unusual behavior.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
How it is given
Possible side effects
- Local tissue irritation
- Ischemia or tissue necrosis (due to epinephrine)
- CNS excitation followed by depression (at toxic doses)
- Cardiovascular depression, hypotension, or arrhythmias (at toxic doses)
- Allergic reactions (ester anesthetics are metabolized to PABA, a known allergen)
Cautions & contraindications
- Intravenous administration
- Use in areas supplied by end-arteries (e.g., tail, ears, digits) due to risk of ischemic necrosis
- Known hypersensitivity to ester-type local anesthetics or PABA
- Epidural use (depending on specific formulation preservatives)
- > **WARNING:** Do not use epinephrine-containing solutions in extremities or areas with collateral-poor circulation (e.g., tail, ears, digits) due to the risk of severe ischemia and tissue sloughing. Always aspirate the syringe before injecting to ensure the needle is not in a blood vessel, as accidental intravenous injection can cause severe cardiovascular and CNS toxicity.
Drug interactions
- Sulfonamide antibiotics: Procaine is metabolized to PABA, which competitively antagonizes the antibacterial effect of sulfonamides.
- Alpha-adrenergic blockers: May antagonize the vasoconstrictive effects of epinephrine.
- Halothane: Sensitizes the myocardium to catecholamines; increased risk of arrhythmias with epinephrine.
Frequently asked questions
What is Procaine with Epinephrine used for in pets?
Your pet has received a local anesthetic to numb a specific area for a procedure. > **Important:** The area may remain numb for a few hours. Prevent your pet from chewing, scratching, or rubbing the numb area, as they could cause severe self-injury without feeling it. Monitor the injection site for any signs of excessive swelling, redness, or skin discoloration, and contact your veterinarian if you notice any unusual behavior.
Is Procaine with Epinephrine safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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