Calcium, Oral (-Carbonate, -Gluconate, -Lactate)

What is oral calcium?

Oral calcium (-carbonate, -gluconate, -lactate) is a calcium supplement and phosphorus binder (reduces the absorption of dietary phosphate). It is used to treat high blood phosphorus levels in cats, dogs, and other animals with chronic kidney disease, and to treat low blood calcium levels in cats, dogs, and other species. Calcium carbonate is rarely used as an antacid in veterinary medicine. Oral calcium supplements are not currently FDA-approved for use in veterinary medicine.

The U.S. Food and Drug Administration (FDA) does not review non-drug health products (e.g., herbals, nutraceuticals, shampoos, and other supplements) for safety or effectiveness before they are sold to the public. Manufacturers of non-drug health products must ensure their products are safe and labeled accurately. The FDA requires that these non-pharmaceuticals contain a disclaimer that says, “This product is not intended to diagnose, treat, cure or prevent any disease.” Health Canada licenses “veterinary health products” after reviewing safety, efficacy, and manufacturing information provided by the manufacturer. These products are not tested by Health Canada.

Your veterinarian is the best source of information about the safety of non-drug health products in pets. Just because a product is natural does not mean it is safe. All medicines and medicinal plants are potentially toxic if used inappropriately or given at high doses. Supplements can also have side effects, like pharmaceuticals. Few supplements and herbs have been subjected to rigorous scientific trials to determine their efficacy. 

Although the information in this handout may be helpful, it also may be incomplete and may not represent the full range of effects the supplement could have on your pet.

How do I give my pet oral calcium?

• Oral calcium comes in powder, tablet, liquid suspension, and capsule forms. 
• All forms are given orally (by mouth).
• Give this medication with food. 
• Give this medication to your pet for the entire time prescribed by your veterinarian, even if it appears your pet is feeling better.

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

What if I miss giving my pet the medication?

If you miss a dose, give it as soon as you remember and then wait the recommended time as prescribed by your veterinarian for the next dose. Do not give the pet two doses at once.

Are there any potential side effects from oral calcium?

Oral calcium may cause the following side effects:

• increase in blood calcium level
• nausea, constipation

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

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 short-acting, meaning that effects will last less than 24 hours, though effects may last longer in pets with kidney or liver disease.

Are there any risk factors for this medication?

Oral calcium should NOT BE USED in pets who

• Are allergic to any component of the medication:
• Have high blood calcium levels
• Are not eating

Oral calcium should be USED WITH CAUTION in pets who:

• Are taking calcitriol

Are there any drug interactions I should be aware of?

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

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

• Aspirin
• Azole antifungals (e.g., itraconazole, ketoconazole)
• Calcitriol
• Cefpodoxime, rifampin
• Corticosteroids (e.g., dexamethasone, prednisolone)
• Digoxin, sotalol
• Diuretics (e.g., furosemide, chlorothiazide)
• Famotidine, ranitidine, omeprazole
• Fluoroquinolone antibiotics (e.g. enrofloxacin)
• Levothyroxine
• Mycophenolate
• Oral bisphosphonates, phosphates
• Propranolol
• Sucralfate
• Tetracyclines

Is any monitoring needed with this medication?

• Your veterinarian may recommend bloodwork to check blood calcium and phosphorus 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 any occur, discontinue the medication and contact your veterinarian.

How do I store oral calcium?

• Store at room temperature (25°C or 77°F).
• 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.