Phenylbutazone (for horses)
Equi-Phar™ Phenylbutazone Injection 20%
Phenylbutazone 20% Injection
Phenylbutazone Tablets (1 g)
Phenylbute® Boluses 1 gram
Phenylbute® Injection 20%
Phenylbutazone is a nonsteroidal anti-inflammatory drug (NSAID) used in horses to control pain and inflammation in the muscles and bones, and to reduce fever. The oral medication should be given with food. The injectable form should only be given I.V. as it will cause pain and/or tissue damage otherwise. Other NSAIDs should be used in dogs and cats as they have fewer toxic side effects than Phenylbutazone.
What is this drug?
• Phenylbutazone is an NSAID (non-steroidal anti-inflammatory); non-narcotic
• Oral Phenylbutazone (powder, paste or tablet) is given by mouth with food and the injectable form should ONLY be given intravenously (I.V.)
Reasons for prescribing:
To treat pain and inflammation in horses, especially good for osteoarthritis
What horses should not take this medication?
• Horses with anemia, bleeding problems, liver, kidney or heart disease
• Horses who are dehydrated or have gastric ulcers
• Foals and ponies as they are more sensitive to the side effects
• Pregnant or nursing animals
• Do not use in animals intended for use in food
• For ethical reasons, do not use in animals prior to a soundness exam as it may mask lameness
• Horses with known hypersensitivity to NSAIDs
Give the exact amount prescribed and only as often as directed. Missed doses reduce the effectiveness of therapy.
If you have difficulty giving Phenylbutazone as prescribed, consult your veterinarian. The dosage form may be able to be changed or another administration technique could be used that is more acceptable to both you and your horse.
Do not mix any other drugs in the same syringe as Phenylbutazone injection.
Do not allow your horse to become dehydrated while on Phenylbutazone. Ensure your horse has adequate access to clean drinking water.
Ideally, give the medication at the same time daily.
What if dose is missed?
If a dose is missed, give it as soon as you can. If it is time already for the next dose, skip the missed dose and go back to the normal schedule. Do not give two doses at the same time.
What to tell/ask veterinarian before giving medication?
Talk to your veterinarian about:
• When will your horse need to be rechecked
• What tests may need to be performed prior to and during treatment with this drug
• Risks and benefits of using this drug
Tell your veterinarian about:
• If your horse has experienced side-effects on other drugs/products
• If your horse has experienced digestive upset now or ever
• If your horse has experienced liver or kidney disease now or ever
• If your horse has experienced any other medical problems or allergies now or ever
• All medicines and supplements that you are giving your horse or plan to give your horse, including those you can get without a prescription. Your veterinarian may want to check that all of your horse's medicines can be given together.
• If your horse is pregnant or nursing or if you plan to breed your horse
Storage and Warnings:
Oral Phenylbutazone should be stored in a tight, light resistant, childproof container in a cool, dry place at room temperature away from heat and direct sunlight. Injectable Phenylbutazone should be refrigerated.
Keep this and all medication out of reach of children and pets.
Call your physician immediately if you accidentally take this product.
Potential side effects:
• Stomach irritation and vomiting
• May cause mouth or stomach ulcers
• Contact your veterinarian if your horse won’t eat, is depressed, has diarrhea, changes drinking or urination habits, is painful or grinds his teeth
• May cause bone marrow suppression and anemia (pale gums, weakness) and/or low white blood cell numbers which can make your horse more susceptible to infections
• May be detectable in the urine for at least 7 days following administration
• May alter laboratory test results. Inform your veterinarian of drug usage prior to any laboratory testing.
• Allergy symptoms to this medication include: scratching, facial swelling, hives, sudden diarrhea, vomiting, shock, seizures, pale gums, cold limbs, or coma
• It is important to stop therapy and contact your veterinarian immediately if you think your horse has a medical problem or side effect from this product's therapy
Can this drug be given with other drugs?
• Yes, but possible interactions may occur with aspirin, barbiturates, chlorpheniramine, corticosteroids, digoxin, diphenhydramine, diuretics, glipizide, penicillin, phenytoin, other NSAIDs or ulcer-causing medications, rifampin, sulfonamides, valproic acid, warfarin or drugs that may cause liver damage.
• Misoprostol may be useful to prevent stomach ulcers due to Phenylbutazone usage
• If your horse experiences any unusual reactions when taking multiple medications, contact your veterinarian
If you see decreased urine production and/or bloody urine, depression, jaundice, fever, anemia (pale gums and weakness), ulcers and/or colic, or if your horse receives more than the prescribed amount of drug, contact your veterinarian immediately.
What else should I know?
Notify your veterinarian if your animal's condition does not improve or worsens despite this treatment.
As with all prescribed medicines, Phenylbutazone should only be given to the horse for which it was prescribed. It should be given only for the condition for which it was prescribed.
This is just a summary of information about Phenylbutazone. If you have any questions or concerns about Phenylbutazone or for the condition it was prescribed, contact your veterinarian.