Calcitriol

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Aug 02, 2023

Warnings


Calcitriol Risks, Warnings, and Complications


Calcitriol can cause or worsen health problems in some people. Talk to your doctor or pharmacist about other treatment options if you are at an increased risk of adverse reactions or complications from this medication. Some of the risks of taking calcitriol include:

  • OVERDOSE AND VITAMIN D TOXICITY: Calcitriol is the active form of vitamin D. Taking too much of this medication can lead to chronic hypercalcemia (dangerously high serum calcium levels that can damage the blood vessels and kidneys). Eat a consistent amount of calcium from all sources every day, including calcium-rich foods, fortified food products, and calcium supplements. Tell your doctor without delay if you notice any signs or symptoms of high calcium levels, such as headache, dry mouth, a metallic taste in your mouth, muscle pain, or bone pain. Keep all your medical and laboratory appointments. Your healthcare provider will order labs to check calcium levels and stop calcitriol if needed.


Precautions Before Starting Calcitriol

Tell your doctor if you have ever had an allergic reaction to calcitriol, any of the active or inactive ingredients in calcitriol capsules or liquid, or any other medications. Your pharmacy can give you a list of ingredients.

Give your doctor and pharmacist a complete list of your medications, including prescription medications, over-the-counter medicines, vitamins, supplements, and herbal products. This can help avoid possible drug interactions between calcitriol and your other medications.

Give your doctor a complete medical history. Calcitriol may not be right for people with certain medical conditions, such as high blood calcium levels, kidney disease, liver disease, recent surgery, or immobility for any reason. 

Ask your doctor which foods are good sources of calcium and how many servings of calcium-rich foods and fortified food products you should eat every day. Also, ask your provider if you need to take a calcium supplement.

Tell your doctor if you are pregnant, could be pregnant, plan to get pregnant, or are breast feeding. People who are breast feeding should not take calcitriol.

Precautions During Use of Calcitriol

Keep all your healthcare appointments during calcitriol treatment. Your doctor will likely start you on a low dose of calcitriol and gradually increase the dose if needed. During the dose adjustment, they will order laboratory tests to check calcium levels.

Eat a consistent amount of calcium during treatment with calcitriol, including from dietary sources and calcium supplements. If you get too much calcium from your diet, you can develop serious side effects from calcitriol. If you do not get enough calcium from your diet, calcitriol will not be able to control your condition. 

If you are undergoing chronic renal dialysis, your healthcare may also recommend a low-phosphate diet to control phosphate levels. Follow these dietary instructions carefully.

Drink plenty of fluids if you have normal renal function. However, if you have kidney disease, ask your provider about how much daily fluid intake is right for you. 

Tell your doctor if you become pregnant while on calcitriol.

Tell all your doctors you are on calcitriol, especially before undergoing any procedure, including dental procedures.

Calcitriol Drug Interactions

Other drugs can affect how calcitriol works. Possible interactions with certain medications can increase the risk of severe adverse effects. 

Tell your doctor and pharmacist if you are currently taking or have taken within the past few months a medicine called ergocalciferol (Deltalin, Drisdol). This medicine is prescribed for hypoparathyroidism, refractory rickets, and familial hypophosphatemia. If you have recently taken ergocalciferol, your provider may need to change your doses and monitor you carefully for side effects.

Some of the other medications that can have interactions with calcitriol include:

  • Calcium supplements
  • Other forms of vitamin D
  • Antacids that contain calcium or magnesium
  • Laxatives that contain magnesium
  • Cholesterol-lowering drugs like cholestyramine (Prevalite, Questran, Cholybar)
  • Diuretics or water pills
  • Heart medications such as digoxin (Lanoxin)
  • Antifungal agents like ketoconazole
  • Medications that lower phosphate levels, such as lanthanum (Fosrenol) and sevelamer (Renagel, Renvela), given to patients on chronic renal dialysis
  • Oral steroids such as methylprednisolone (Medrol), prednisone (Rayos), and dexamethasone
  • Anti-seizure medications such as phenobarbital and phenytoin (Dilantin, Phenytek)

Give your doctor or pharmacist a complete list of your medications, including prescription drugs, nonprescription drugs, dietary supplements, and herbal remedies. Also, tell your healthcare professional if you smoke, drink alcohol, or use recreational drugs because some of these substances can cause serious health complications when used with prescription medications.