Common Uses:Off Label Uses:Side Effects:
The common side effects of Rocaltrol are:
Since Rocaltrol is believed to be the active hormone which exerts vitamin D activity in the body, adverse effects are, in general, similar to those encountered with excessive vitamin D intake, ie, hypercalcemia syndrome or calcium intoxication (depending on the severity and duration of hypercalcemia).

Early: weakness, headache, somnolence, nausea, vomiting, dry mouth, constipation, muscle pain, bone pain, metallic taste, and anorexia, abdominal pain or stomach ache.

Late: polyuria, polydipsia, anorexia, weight loss, nocturia, conjunctivitis (calcific), pancreatitis, photophobia, rhinorrhea, pruritus, hyperthermia, decreased libido, elevated BUN, albuminuria, hypercholesterolemia, elevated SGOT (AST) and SGPT (ALT), ectopic calcification, nephrocalcinosis, hypertension, cardiac arrhythmias, dystrophy, sensory disturbances, dehydration, apathy, arrested growth, urinary tract infections, and, rarely, overt psychosis.
Teratogenic Effects
Pregnancy Category C. Rocaltrol has been found to be teratogenic in rabbits when given at doses of 0.08 and 0.3 mcg/kg (approximately 2 and 6 times the maximum recommended dose based on mg/m2). All 15 fetuses in 3 litters at these doses showed external and skeletal abnormalities. However, none of the other 23 litters (156 fetuses) showed external and skeletal abnormalities compared with controls.

Teratogenicity studies in rats at doses up to 0.45 mcg/kg (approximately 5 times maximum recommended dose based on mg/m2) showed no evidence of teratogenic potential. There are no adequate and well-controlled studies in pregnant women. Rocaltrol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Cautions / Warnings:Drug Interactions:
Some of the drug interactions that could result when used in conjuctions with other medications is as stated below:

Cholestyramine
Cholestyramine has been reported to reduce intestinal absorption of fat-soluble vitamins; as such it may impair intestinal absorption of Rocaltrol.

Phenytoin/Phenobarbital
The coadministration of phenytoin or phenobarbital will not affect plasma concentrations of calcitriol, but may reduce endogenous plasma levels of 25(OH)D3 by accelerating metabolism. Since blood level of calcitriol will be reduced, higher doses of Rocaltrol may be necessary if these drugs are administered simultaneously.

Thiazides
Thiazides are known to induce hypercalcemia by the reduction of calcium excretion in urine. Some reports have shown that the concomitant administration of thiazides with Rocaltrol causes hypercalcemia. Therefore, precaution should be taken when coadministration is necessary.

Digitalis
Calcitriol dosage must be determined with care in patients undergoing treatment with digitalis, as hypercalcemia in such patients may precipitate cardiac arrhythmias.

Ketoconazole
Ketoconazole may inhibit both synthetic and catabolic enzymes of calcitriol. Reductions in serum endogenous calcitriol concentrations have been observed following the administration of 300 mg/day to 1200 mg/day ketoconazole for a week to healthy men. However, in vivo drug interaction studies of ketoconazole with Rocaltrol have not been investigated.

Corticosteroids
A relationship of functional antagonism exists between vitamin D analogues, which promote calcium absorption, and corticosteroids, which inhibit calcium absorption.

Phosphate-Binding Agents
Since Rocaltrol also has an effect on phosphate transport in the intestine, kidneys and bones, the dosage of phosphate-binding agents must be adjusted in accordance with the serum phosphate concentration.

Vitamin D
Since calcitriol is the most potent active metabolite of vitamin D3, pharmacological doses of vitamin D and its derivatives should be withheld during treatment with Rocaltrol to avoid possible additive effects and hypercalcemia.