Alendronate

What is alendronate?

Alendronate is a bone resorption inhibitor used to treat high levels of calcium in the blood in cats and dogs. It may also be used as part of the treatment plan for some types of bone cancer. It has been used to treat feline odontoclastic resorptive lesions (FORLs or tooth resorption) in cats.

It is used off label (extra label) in veterinary medicine. 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 alendronate?

• Alendronate comes in tablet and liquid suspension forms. 
• All forms are given orally (by mouth).
• Give your pet this medication without food, on an empty stomach. 
• Do not offer food for at least 30 minutes after dosing. Small amounts of water after giving the medication are fine.
• Measure liquid forms carefully.
• Give this medication to your pet for the entire time prescribed by your veterinarian, even if it appears that your pet is feeling better.

This medication should take effect within a few days, though effects may not be noticeable.

What if I miss giving my pet the medication?

Give the missed dose as soon as you remember and then wait the recommended time between doses, as prescribed by your veterinarian. Do not give the pet two doses at once.

Are there any potential side effects from alendronate?

Alendronate may cause the following side effects:

• Vomiting
• Lack of appetite

The following reactions are rare, but if they occur, contact your veterinarian immediately:

• An allergic reaction such as irregular breathing, rash, fever, puffiness and swelling around the face
• Sores or ulcers in the mouth or throat, pain (particularly bone and jaw pain), excessive drooling 

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 medication is long-acting, meaning that effects will last several weeks, though effects may last longer in pets with kidney or liver disease.

Are there any risk factors for this medication?

Alendronate should NOT BE USED in pets who:

• Are allergic to any component of the medication
• Have severe kidney disease

Alendronate should be USED WITH CAUTION in pets who:

• Have trouble swallowing or problems with their esophagus or throat

Are there any drug interactions I should be aware of?

Certain medications should be USED WITH CAUTION when given with alendronate, including: 

• Aspirin
• Aminoglycosides
• Oral calcium, magnesium, aluminum
• Estrogens (e.g., diethylstilbestrol) 
• NSAIDs (e.g., carprofen, meloxicam)
• Omeprazole and other proton-pump inhibitors
• Diuretics (e.g. furosemide)
• Famotidine, ranitidine

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.

Is any monitoring needed with this medication?

• Your veterinarian may recommend blood work to check blood calcium levels.
• Your veterinarian may schedule follow-up visits for monitoring. In this case, follow your veterinarian’s directions.
• At home, monitor for any abnormal changes. If these occur, discontinue the medication and contact your veterinarian.

How do I store alendronate?

• Store at room temperature of 20°C-25°C (68°F-77°F).
• Do not freeze.
• Keep 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. Adverse effects should be reported to the FDA or Health Canada.