Generic Name

calcitriol (cal SIT ree ol)


Trade Name



What is calcitriol?

Calcitriol is a derivative of vitamin D. This vitamin is necessary and important for the proper absorption and use of calcium in the body. Calcium, of course, is the major mineral in bones and teeth, and gives them their strength. As individuals, especially females, age and when steroid medication such as prednisone are used, the bones actually lose calcium and osteoporosis occurs. When bones are weakened like this, they are prone to fracture with serious consequences.


What is it used for?

In gastroenterology, the drug is used along with oral calcium to prevent bone loss, which can occur with steroid (prednisone) use and with certain liver conditions such as primary biliary cirrhosis and primary sclerosing cholangitis. It is also used to treat low blood calcium seen in chronic kidney dialysis patients, in parathyroid hormone problems and in a condition called psoriasis vulgaris.


How do I take it?

Follow your physician’s instructions carefully. Calcitriol may be taken with food, milk or on an empty stomach. Swallow whole, do not crush or chew the pill. Store in a tightly sealed container away from light and heat. Keep all medications away from children. Never share your medications with anyone else.


What do I do for a missed dose?

If you miss a dose of this medicine, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and return to your regular schedule. Do not double up on this medication.


Are there interactions with food or beverages?

There are no known interactions with food or beverages. Your calcium levels should be monitored while on this drug. It is usually desirable to increase your daily intake of calcium with dairy products or to take a calcium supplement. Check with your physician.


Are there interactions with other drugs?

An interaction generally means that one drug may increase or decrease the effect of another drug. Also, the more medications a person takes, the more likely there will be a drug interaction.

Interactions with this drug may occur with the following:

  • mineral oil
  • magnesium containing antacids
  • digoxin (Lanoxin)
  • verapamil (Calan)
  • cholestyramine (Questran)
  • phenytoin (Dilantin)
  • thiazide diuretics (Dyazide, hydrochlorothiazide)
  • Parbiturates (phenobarbital)


Is there a problem if I have another disorder or disease?

At times, a drug may have a different or enhanced effect when other diseases are present. At other times, the drug may worsen or effect another disease. Patients with chronic kidney disease may have significant fluctuation of their blood calcium levels. Close contact with the physician and regular blood studies are necessary.


What about allergies?

People who have known allergies or asthma may be at an increased risk for a reaction from any new medication. The physician should always know a patient’s allergy history. Signs of an allergic reaction are skin rash, hives or itching. Of course, a person should not take calcitriol if there has been a previous reaction to this or vitamin D.


What if I’m pregnant, considering pregnancy or breast-feeding?

Most females now know that, if possible, no drug, including alcohol, should be taken during pregnancy or lactation. The potential danger, of course, is an injury to the baby. However, some drugs are much safer than others in this regard. So, the FDA has a grading system for each drug which reflects what is known medically. It ranks drugs from A, where medical studies show no evidence for danger to the fetus or mother, to B, C, D and X, where the medical evidence indicates that the risk to the fetus outweighs any benefit to the mother. Calcitriol is ranked C. Always consult your physician before taking any drug during or when planning pregnancy.


What are the effects on sexual function?

With long-term use of calcitriol, there can be a decrease in sex drive.


Are there other precautions?

Take the exact dose of the drug that has been prescribed. Taking extra doses may raise the calcium blood level into a toxic range.


How long is it safe to take calcitriol?

Long-term use of this drug is necessary and safe, provided periodic physician supervision and dosage adjustments occur.


How about side effects?

Adverse reactions can occur with any drug, even over-the-counter medications. Some of these are mild such as a stomach upset, which may be avoided by taking the medication with food. Minor reactions may go away on their own but if they persist, contact the physician. For major reactions, the patient should contact the physician immediately. This drug has no side effects if taken at the proper dosage.

For calcitriol, the following are the effects of an overdose:


  • persistent headache
  • fatigue
  • weakness
  • dry mouth
  • metallic taste
  • thirst
  • nausea
  • vomiting
  • diarrhea


A physician’s comment…

As the population gets older, more and more people are confronted with the problem of bone loss. It is now well-known that osteoporosis can be prevented or delayed by not smoking, by regular exercise and avoiding excessive alcohol. A hip fracture in an elderly individual is really a disaster as up to 50% of these people will die within one year. So, prevention is the key. The above lifestyle changes and adequate amounts of oral calcium and vitamin D are necessary. When cortisone (steroids, prednisone) is used for a medical condition, the need is even greater.