Calcitriol is used to treat and prevent low levels of calcium and bone disease in patients whose kidneys or parathyroid glands (glands in the neck that release natural substances to control the amount of calcium in the blood) are not working normally. It is also used to treat secondary hyperparathyroidism (a condition in which the body produces too much parathyroid hormone [PTH; a natural substance needed to control the amount of calcium in the blood]) and metabolic bone disease in people with kidney disease. Calcitriol is in a class of medications called vitamin D analogs. It works by helping the body to use more of the calcium found in foods or supplements and regulating the body's production of parathyroid hormone.
Calcitriol comes as a capsule and a solution (liquid) to take by mouth. It usually is taken once a day or once every other day in the morning with or without food. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take calcitriol exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Your doctor will probably start you on a low dose of calcitriol and may gradually increase your dose depending on your body's response to calcitriol.
Calcitriol is also sometimes used to treat rickets (softening and weakening of bones in children caused by lack of vitamin D), osteomalacia (softening and weakening of bones in adults caused by lack of vitamin D), and familial hypophosphatemia (rickets or osteomalacia caused by decreased ability to break down vitamin D in the body). Calcitriol is also sometimes used to increase the amount of calcium in the blood of premature babies. Talk to your doctor about the risks of using this medication for your condition.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
Calcitriol will work only if you get the right amount of calcium from the foods you eat. If you get too much calcium from foods, you may experience serious side effects of calcitriol, and if you do not get enough calcium from foods, calcitriol will not control your condition. Your doctor will tell you which foods are good sources of these nutrients and how many servings you need each day. If you find it difficult to eat enough of these foods, tell your doctor. In that case, your doctor can prescribe or recommend a supplement.
If you are being treated with dialysis (process of cleaning the blood by passing it through a machine), your doctor may also prescribe a low-phosphate diet. Follow these directions carefully.
If you do not have kidney disease, you should drink plenty of fluids while taking calcitriol. If you have kidney disease, talk to your doctor about how much fluid you should drink each day.
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.