What  is calcitriol? 

Calcitriol is vitamin D3. Vitamin  D is important for the absorption of calcium from the stomach  and for the functioning of calcium in the body. 

Calcitriol is used to treat calcium deficiency with hypoparathyroidism (decreased functioning  of the  parathyroid glands) and metabolic bone disease  in people with chronic kidney failure. 

Calcitriol may also be used for other purposes not listed in this medication guide. 

What is  the most important information I should know about calcitriol? 

Do not use this medication if you have ever had an allergic reaction  to vitamin D, or if you have high levels  of calcium or vitamin D  in your blood. Drink plenty of fluids unless your doctor has told you to restrict your fluid intake. Call your doctor if you have ongoing vomiting or diarrhea or if you  are sweating more than usual. Becoming dehydrated while taking calcitriol can lead to an electrolyte imbalance. Do  not take other vitamin or mineral supplements unless your doctor has told you to. 

Avoid using antacids without your doctor's advice. Use only the specific type  of antacid your doctor recommends. Antacids contain different minerals and some types can  cause serious side effects if you take them together with calcitriol. 

To be sure this medication is helping your condition; your blood will need to be tested on a regular basis. Do not miss any scheduled appointments. 

Calcitriol is only part of  a complete program  of treatment that may also include a special diet.  It is very important to follow the diet plan created for you  by your doctor or nutrition counselor. You should become very familiar with  the list  of foods you must eat  or avoid to help control your condition. 

What  should I discuss with my healthcare provider before taking calcitriol? 

Do not use this medication if you have ever had an allergic reaction to vitamin D, or if you have: 

• high levels of calcium in your blood (hypercalcemia); or 
• High levels of vitamin D in your body (hypervitaminosis D). 

Before taking calcitriol, tell your doctor about all of your medical conditions. You may not be able  to take calcitriol, or you may need  a dose adjustment  or special tests to safely take this medication. 

FDA pregnancy category C. This medication may be harmful to an unborn baby. Tell  your doctor if you are pregnant  or plan to become pregnant during treatment. Calcitriol can pass into breast milk and may harm a nursing baby. Do  not use this medication without telling your doctor if you are breast-feeding a baby. 

How should I take calcitriol? 

Take this medication  exactly as prescribed by your doctor.  Do not take it in larger amounts  or for longer  than recommended. Follow the directions on  your prescription label. 

Your doctor may occasionally change your dose to make sure  you get the best results from this medication. 

Measure liquid medicine with  a special dose-measuring spoon or cup, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one. 

Drink plenty  of fluids unless  your doctor has told you to restrict your fluid intake. Call your doctor if you have ongoing vomiting or diarrhea or if you are sweating  more than usual. Becoming dehydrated while taking calcitriol can lead to an electrolyte imbalance. 

To be sure this medication is helping  your condition; your blood  will need  to be tested on a regular basis. You may need blood tests as often as twice a week when  you first start taking calcitriol.  Do not miss any scheduled appointments. 

Calcitriol is only part  of a complete program  of treatment that may also include a special diet. It  is very important  to follow the diet plan created for you by  your doctor or nutrition counselor. You should become very familiar with  the list of foods you must eat or avoid to help control  your condition.

If you need to  be on bed-rest or have any type of surgery,  your dose or testing needs may change. Follow your doctor's instructions. Store  this medication at room temperature away from moisture, light, and heat. 

What happens if I miss a dose? 

Take  the missed dose as soon as you remember. If it  is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do  not take extra medicine to make up the missed dose. 

What happens if I overdose? 

Seek emergency medical attention if you think you have used too much of this medicine. 

Overdose symptoms may include increased thirst or urination, uneven heart rate, weakness, behavior changes,  bone pain, nausea, weight loss, decreased appetite, constipation, or a  metallic taste in the mouth. 

What should I avoid while taking calcitriol? 

Do not take other vitamin or mineral supplements unless your doctor has told you to. 

Avoid using antacids without your doctor's advice. Use only the specific type of antacid your doctor recommends. Antacids contain different minerals and some types can cause serious side effects if you take them together with calcitriol. 

Calcitriol side effects 

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop taking calcitriol and call your doctor at once if you have any of these serious side effects: 

• increased thirst, 
• urinating more than usual; 
• pain in your lower back; 
• fast, slow,  or uneven heart rate; 
• weakness, drowsiness,  changes in behavior;
• bone pain, muscle weakness, loss of height; 
• nausea, constipation, loss  of appetite, weight loss; 
• slow growth (in a child taking calcitriol); or 
• Dry mouth  or a metallic taste. 

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual  or bothersome side effect. 

What other drugs will affect calcitriol?

Before taking calcitriol, tell your doctor if you are taking any  of the following medicines: 

• digoxin (digitalis, Lanoxin, Lanoxicaps); 
• cholestyramine (Questran, Prevalite); 
• sevelamer (Renagel);
• ketoconazole (Nizoral); 
• lanthanum (Fosrenol); 
• seizure medication such as phenytoin (Dilantin) or phenobarbital (Solfoton); 
• steroids such as prednisone, fluticasone (Advair), mometasone (Asmanex, Nasonex), dexamethasone (Decadron, Hexadrol) and others; or 
• a (water pill) diuretic such as hydrochlorothiazide (HCTZ, Esidrix, Hydrodiuril, Microzide,Oretic), chlorothiazide (Diuril), chlorthalidone (Hygroton, Thalitone), indapamide (Lozol), metolazone (Mykrox, Zaroxolyn), and others. 

This list is not complete and there may be other drugs that can interact with calcitriol. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor. 

Where can I get more information? 

• Your pharmacist can provide more  information about calcitriol. 
• Remember, keep this and  all other medicines out of the reach of children, never share  your medicines with others,  and use this medication only for  the indication prescribed
• The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If  you have questions about the drugs you are taking, check with  your doctor, nurse or pharmacist.