5 WARNINGS AND PRECAUTIONS
5.1 Hypercalcemia
Hypercalcemia may occur during Doxercalciferol Injection treatment. Acute hypercalcemia may increase the risk of cardiac arrhythmias and seizures and may potentiate the effect of digitalis on the heart [see Warnings and Precautions (5.2)]. Chronic hypercalcemia can lead to generalized vascular calcification and other soft-tissue calcification. Severe hypercalcemia may require emergency attention.
Hypercalcemia may be exacerbated by concomitant administration of high doses of calcium-containing preparations, thiazide diuretics, or other vitamin D compounds [see Drug Interactions (7)]. In addition, high intake of calcium and phosphate concomitantly with vitamin D compounds may lead to hypercalciuria and hyperphosphatemia. Patients with a history of hypercalcemia prior to initiating therapy may be at increased risk for development of hypercalcemia with Doxercalciferol Injection. In these circumstances, frequent serum calcium monitoring and Doxercalciferol Injection dose adjustments may be required.
When initiating Doxercalciferol Injection or adjusting Doxercalciferol Injection dose, measure serum calcium weekly. Once a maintenance dose has been established, measure serum calcium monthly for 3 months and then every 3 months. If hypercalcemia occurs, reduce the dose or discontinue Doxercalciferol Injection until serum calcium is normal [see Dosage and Administration (2)].
Inform patients about the symptoms of elevated calcium (feeling tired, difficulty thinking clearly, loss of appetite, nausea, vomiting, constipation, increased thirst, increased urination and weight loss) and instruct them to report new or worsening symptoms when they occur.
5.2 Digitalis Toxicity
Doxercalciferol Injection can cause hypercalcemia [see Warnings and Precautions (5.1)] which increases the risk of digitalis toxicity. In patients using Doxercalciferol Injection concomitantly with digitalis compounds, monitor both serum calcium and patients for signs and symptoms of digitalis toxicity. Increase the frequency of monitoring when initiating or adjusting the dose of Doxercalciferol Injection [see Drug Interactions (7)].
5.3 Serious Hypersensitivity Reactions
Serious hypersensitivity reactions, including fatal outcome, have been reported post marketing in patients on hemodialysis following administration of Doxercalciferol Injection. Hypersensitivity reactions include anaphylaxis with symptoms of angioedema (involving face, lips, tongue and airways), hypotension, unresponsiveness, chest discomfort, shortness of breath, and cardiopulmonary arrest. These reactions may occur separately or together.
Monitor patients receiving Doxercalciferol Injection upon initiation of treatment for hypersensitivity reactions. Should a hypersensitivity reaction occur, discontinue Doxercalciferol Injection, monitor and treat if indicated [see Contraindications (4)].
5.4 Adynamic Bone Disease
Adynamic bone disease with subsequent increased risk of fractures may develop if intact PTH levels are suppressed by Doxercalciferol Injection to abnormally low levels. Monitor intact PTH levels to avoid oversuppression and adjust the Doxercalciferol Injection dose, if needed [see Dosage and Administration (2)].