Calcitriol is a man-made active form of vitamin D. Most people get enough vitamin D from exposure to the sun and from fortified food products (e.g., dairy products, vitamins). Vitamin D helps control parathyroid hormone and the levels of certain minerals (e.g., calcium, phosphorus) that are needed for building and keeping strong bones.Before regular vitamin D can be used by the body, it needs to be changed to the active form by the liver and kidneys. Calcitriol is used in patients with kidney disease who can’t make enough of the active form of Vitamin D. This medication is also used to prevent and treat certain types of calcium/phosphorus/parathyroid problems that can happen with long-term kidney dialysis or hypoparathyroidism. Calcitriol is usually used along with specific diet recommendations and sometimes other medications.
How to use Calcitriol
Take this medication by mouth with or without food, usually once daily or as directed by your doctor. If you are using the liquid form, measure your dose with a special measuring spoon or device. Do not use a normal household spoon since you may not get the correct dose.
Dosage is based on your medical condition and response to therapy. Your doctor may start you on a low dose and adjust the dose slowly to find the best dose for you. Follow your doctor’s directions carefully. Use this medication regularly in order to get the most benefit from it. To help you remember, take it at the same time each day.
It is very important to follow the diet recommended by your doctor to get the most benefit from this medication and to prevent serious side effects. Do not take other supplements/vitamins (e.g., calcium, vitamin D) unless ordered by your doctor.
Certain medications (bile acid sequestrants such as cholestyramine/colestipol, mineral oil, orlistat) can decrease the absorption of vitamin D. Therefore, separate your doses of these medications as far as possible from your doses of calcitriol (at least 2 hours apart, longer if possible). It may be easiest to take calcitriol at bedtime if you are also taking these other medications. Ask your doctor or pharmacist about finding a good dosing schedule that will work with all your medications.
Calcitriol does not usually have side effects. Your doctor may check your calcium and phosphate blood levels and adjust your dose if you have side effects.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if any of these unlikely but serious side effects occur: loss of appetite, back/bone/joint/muscle pain, constipation, dry mouth, eye pain/redness/sensitivity to light, headache, fast/slow/irregular heartbeat, nausea/vomiting/diarrhea, sleepiness, stomach/abdominal pain, increased thirst, signs of kidney problems (such as change in the amount of urine), weakness.
A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.