Calcitriol Capsules

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking calcitriol it is important that your doctor knows:

• If you are pregnant or breast-feeding.
• If you know you have too much calcium in your blood or urine. This can happen with some cancers.
• If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
• If you have ever had an allergic reaction to a medicine.

• Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress. Your doctor will want you to have regular blood tests to check on the amount of calcium in your blood and also on how well your kidneys are working.
• Your doctor or dietician will discuss with you how to maintain a well-balanced and healthy diet. Please follow any advice you are given about what to eat and drink. It is important that you have plenty to drink so that you don't become dehydrated and that you don't eat foods that have been fortified with vitamin D.
• Treatment with calcitriol is often long-term. Continue to take the capsules regularly unless you are told otherwise by your doctor.

• If you have an allergy to calcitriol or any other part of this medicine (calcitriol capsules).
• If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
• If you have any of these health problems: High calcium levels or too much vitamin D in the body.
• If you are breast-feeding. Do not breast-feed while you take this medicine.

This is not a list of all drugs or health problems that interact with this medicine (calcitriol capsules).

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

• Tell all of your health care providers that you take this medicine (calcitriol capsules). This includes your doctors, nurses, pharmacists, and dentists.
• Have blood work checked as you have been told by the doctor. Talk with the doctor.
• Talk with your doctor about whether you may need to take calcium while taking this medicine.
• If you are taking other sources of vitamin D, talk with your doctor.
• Do not take products that have magnesium with this medicine (calcitriol capsules). This includes some types of antacids. Talk with your doctor.
• Drink lots of noncaffeine liquids unless told to drink less liquid by your doctor.
• Follow the diet plan that your doctor told you about.
• If you take cholestyramine, talk with your pharmacist about how to take with this medicine.
• Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using this medicine (calcitriol capsules) while you are pregnant.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if you have any side effects that bother you or do not go away.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

Calcitriol is a synthetic vitamin D analog which is active in the regulation of the absorption of calcium from the gastrointestinal tract and its utilization in the body. Calcitriol Capsules are available as containing either 0.25 mcg or 0.5 mcg calcitriol, USP. Calcitriol Capsules contain butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as antioxidants. The capsules also contain medium chain triglycerides. Gelatin capsule shells contain FD&C Yellow No. 6, gelatin, glycerin, methyl paraben sodium, propyl paraben sodium, purified water, and titanium dioxide. The 0.5 mcg capsules also contain FD&C Red No. 40.

Calcitriol, USP is a white, crystalline compound which occurs naturally in humans. It has a calculated molecular weight of 416.65 and is soluble in organic solvents but relatively insoluble in water. Chemically, calcitriol, USP is 9,10- seco(5Z,7E)-5,7,10(19)-cholestatriene-1α, 3β, 25-triol and has the following structural formula:

The other names frequently used for calcitriol, USP are 1α,25-dihydroxycholecalciferol, 1,25-dihydroxyvitamin D3, 1,25-DHCC, 1,25(OH)2D3 and 1,25-diOHC.

Calcitriol, USP should not be given to patients with hypercalcemia or evidence of vitamin D toxicity. Use of Calcitriol Capsules in patients with known hypersensitivity to calcitriol, USP (or drugs of the same class) or any of the inactive ingredients is contraindicated.

Overdosage of any form of vitamin D is dangerous (see OVERDOSAGE). Progressive hypercalcemia due to overdosage of vitamin D and its metabolites may be so severe as to require emergency attention. Chronic hypercalcemia can lead to generalized vascular calcification, nephrocalcinosis and other soft-tissue calcification. The serum calcium times phosphate (Ca x P) product should not be allowed to exceed 70 mg2/dL2. Radiographic evaluation of suspect anatomical regions may be useful in the early detection of this condition.

Calcitriol is the most potent metabolite of vitamin D available. The administration of calcitriol to patients in excess of their daily requirements can cause hypercalcemia, hypercalciuria, and hyperphosphatemia. Therefore, pharmacologic doses of vitamin D and its derivatives should be withheld during calcitriol treatment to avoid possible additive effects and hypercalcemia. If treatment is switched from ergocalciferol (vitamin D2) to calcitriol, it may take several months for the ergocalciferol level in the blood to return to the baseline value (see OVERDOSAGE).

Calcitriol increases inorganic phosphate levels in serum. While this is desirable in patients with hypophosphatemia, caution is called for in patients with renal failure because of the danger of ectopic calcification. A nonaluminum phosphate-binding compound and a low-phosphate diet should be used to control serum phosphorus levels in patients undergoing dialysis.

Magnesium-containing preparations (eg, antacids) and calcitriol should not be used concomitantly in patients on chronic renal dialysis because such use may lead to the development of hypermagnesemia.

Studies in dogs and rats given calcitriol for up to 26 weeks have shown that small increases of calcitriol above endogenous levels can lead to abnormalities of calcium metabolism with the potential for calcification of many tissues in the body.