Gemfibrozil

What is gemfibrozil?

Gemfibrozil is a medication prescribed off-label by veterinarians for use in dogs and cats to treat high levels of fat (lipids) within the blood that have not been controlled by dietary modifications. Gemfibrozil may also be used occasionally in birds for the treatment of high blood lipid levels.

Information on gemfibrozil's benefits and adverse effects in animals is still being determined.

Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.

How do I give my pet gemfibrozil?

Gemfibrozil comes as oral tablets or capsules that are given by mouth.

• Gemfibrozil should be given on an empty stomach or about 30 minutes before a meal.
• If vomiting occurs when dosed on an empty stomach, give future doses with food or a treat.
• If you have difficulty getting your animal to take the medicine, contact your veterinarian or pharmacist for tips to help with dosing and to reduce the stress of medication time for both you and your animal.
• For this medication to work, it is important to follow your veterinarian’s instructions for diet modification. 

This medication will take several doses before you see any effect. The medication’s full effects may not be evident until your animal has taken it consistently for several weeks. However, effects may not be noted outwardly, and laboratory tests may need to be done to evaluate this medication’s effectiveness. 

What if I miss giving my pet the medication?

If you miss a dose of gemfibrozil, give it as soon as you remember, and then continue with the regular dosing schedule. However, if it is almost time for the next dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once. 

Are there any potential side effects from gemfibrozil?

Gemfibrozil may cause the following side effects:

• vomiting
• diarrhea

Serious adverse reactions associated with this drug may occur without warning and could, in rare cases, lead to death. If any of the following signs develop, stop giving gemfibrozil and contact your veterinarian immediately:

• abdominal pain
• yellowing of the skin, gums, or eyes (jaundice)
• low energy, loss of appetite
• Drug sensitivities can develop over time with repeated exposure. Your pet may have no reaction after the first few doses but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment.
• Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. 

This short-acting medication should stop working within 24 hours, although effects may be longer in pets with liver or kidney disease. 

Are there any risk factors for this medication?

This medication should NOT BE USED in animals that:

• are allergic to it or have had poor reactions to it previously 
• have advanced liver or kidney disease
• have pre-existing liver (biliary) disease

Are there any drug interactions I should be aware of?

Certain medications may interact with gemfibrozil and so it is important to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your dog is taking before starting any new treatment.

Several medications should be used with caution when given with gemfibrozil, including:

• amiodarone
• beta-adrenergic receptor antagonists (e.g., atenolol, propranolol)
• colchicine
• estrogens
• glipizide, glyburide, and glimeperide
• insulin
• loperamide
• statins (e.g., atorvastatin, simvastatin)
• thiazide diuretics
• ursodiol
• warfarin

Is any monitoring needed with this medication?

• A complete blood count (CBC) should be monitored periodically for the first 12 months of treatment.
• Liver function blood tests should be monitored regularly for pets treated with gemfibrozil long-term.
• Blood lipid levels should be measured periodically to assess whether this drug is working.
• Your veterinarian will let you know when they want to reassess your pet to ensure the medication is working and not causing side effects. 
• At home, monitor for any side effects such as those noted above. If any side effects occur, discontinue use of the medication and contact your veterinarian. 

How do I store gemfibrozil?

• Tablets should be stored at 20°C–25°C (68°F–77°F).
• Protect from light and humidity.
• Keep this and all medication out of reach of children and pets.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.