2 DOSAGE AND ADMINISTRATION
2.1 Prior to Initiation of Doxercalciferol Injection
- Ensure serum calcium is not above the upper limit of normal before initiating treatment with Doxercalciferol Injection [see Warnings and Precautions (5.1)].
2.2 Important Administration Instructions for Doxercalciferol Injection
- Administer Doxercalciferol Injection intravenously as a bolus dose at the end of dialysis.
- Inspect Doxercalciferol Injection visually prior to administration; the solution should appear clear and colorless. Do not use if the solution is not clear or particles are present.
- After initial vial use, store opened multiple-dose vial for up to 14 days at room temperature. Discard unused portion of multiple-dose vial after 14 days [see How Supplied/Storage and Handling (16)].
2.3 Dosage Recommendations for Doxercalciferol Injection
- Initiate Doxercalciferol Injection at a dose of 4 mcg given by bolus intravenous administration three times weekly at the end of dialysis (no more frequently than every other day).
- Target the maintenance dose of Doxercalciferol Injection to intact parathyroid hormone (PTH) levels within the desired therapeutic range and serum calcium within normal limits.
- Monitor serum calcium, phosphorus, and intact PTH levels weekly after initiation of therapy or dose adjustment.
- Titrate the dose of Doxercalciferol Injection based on intact PTH. The dose may be increased at 8-week intervals by 1 mcg to 2 mcg if intact PTH is not lowered by 50% and fails to reach the target range. The maximum dose is 18 mcg weekly. Prior to raising the dose, ensure serum calcium is within normal limits.
- Suspend or decrease the dose if intact PTH is persistently and abnormally low to reduce the risk of adynamic bone disease [see Warnings and Precautions (5.4)] or if serum calcium is consistently above the normal range to reduce the risk of hypercalcemia [see Warnings and Precautions (5.1)]. If suspended, the drug should be restarted one week later at a dose that is at least 1 mcg lower.
2.4 Drug Interactions that May Require Dosage Adjustments of Doxercalciferol Injection
- Increased monitoring of serum calcium and dose adjustment of Doxercalciferol Injection may be necessary when given concomitantly with drugs that may increase the risk of hypercalcemia [see Drug Interactions (7)].
- Increased monitoring of both serum calcium and intact PTH as well as dose adjustment of Doxercalciferol Injection may be necessary when given concomitantly with cytochrome P450 inhibitors or enzyme inducers [see Drug Interactions (7)].