What is calcitriol?
Calcitriol (brand names: Rocaltrol®, Calcijex®) is a form of vitamin D used to treat low blood calcium associated with low parathyroid gland function. It may also be helpful in treating chronic kidney disease, certain cancers such as mast cell tumors, and certain skin diseases.
"Many drugs are commonly prescribed for off-label use in veterinary medicine."
Its use in cats and dogs to treat low blood calcium is “off label” or “extra label”. Many drugs are commonly prescribed for off-label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.
How is calcitriol given?
- Calcitriol is given by mouth, in the form of a capsule or liquid. It can also given by injection in the hospital.
- It should be given on an empty stomach, preferably at bedtime.
- If your pet vomits or acts sick after dosing on an empty stomach, give future doses with food or a treat.
- Measure liquid forms carefully.
- Do not give calcium supplements while using this medication.
This medication should take effect within 1 to 2 days, but effects may not be obvious for several weeks. Effects may not be noted outwardly, so laboratory tests may be required to evaluate this medication’s effectiveness.
What if I miss giving my pet the medication?
If you miss a dose, 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?
Side effects are uncommon if the dose is appropriate.
If the dose is too high, it may cause the following side effects:
- increased drinking and urination
- lack of appetite
If the dose is too low, it may cause the following side effects:
- muscle tremors
- twitching
- facial itching
- stiffness
- weakness
- unsteadiness
- seizures
This short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.
Are there any risk factors for this medication?
Calcitriol should NOT BE USED in pets that:
- are allergic to it
- have high blood calcium
- have vitamin D toxicity
- have malabsorption syndrome (cannot adequately absorb nutrients from the gastrointestinal tract)
Calcitriol should be USED WITH EXTREME CAUTION in pets that:
- have high blood phosphorus levels
- are pregnant or lactating
- are prone to calcium oxalate urinary stones
Are there any drug interactions I should be aware of?
The following medications should be used with caution when given with calcitriol:
- calcium-containing phosphorus binding agents
- barbiturates
- corticosteroids
- magnesium-containing antacids
- thiazide diuretics
Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.
Is any monitoring needed with this medication?
- Before your pet starts this medication, your veterinarian may check Ionized blood calcium levels, blood phosphorus levels, and kidney values. These levels and values should be monitored after one week of treatment, and then every 2 to 4 weeks.
- Blood parathyroid hormone levels should also be monitored.
- Your veterinarian may monitor your pet to be sure the medication is working.
How do I store calcitriol?
- Store at room temperature between 59°F and 86°F (15°C and 30°C).
- Protect from light.
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.
