地拉罗司推荐使用量是多少呢？

It is the only oral iron ion chelator developed by Novartis and was approved by the FDA in November 2005. So, what is the recommended dosage of deferasirox?

The recommended dose of deferasirox is 20 mg/kg.

For patients who receive monthly transfusions of more than 14 mL/kg of packed red blood cells (ie, more than 4 units/month in adults) and who need to reduce excess iron exposure, a starting dose of 30 mg/kg/day may be considered.

For patients who receive monthly transfusions of less than 7 mL/kg of packed red blood cells (i.e., less than 2 units/month in adults) and who need to maintain body iron balance, a starting dose of 10 mg/kg/day may be considered.

In patients who have responded well to deferoxamine therapy, an initial dose of deferasirox equal to one-half the deferoxamine dose may be considered. (For example, a patient receiving deferoxamine 40 mg/kg/day 5 days per week or equivalent may start at 20 mg/kg if switched to deferasirox.)

Drug metabolism of deferasirox:

1. Absorption: After oral administration of deferasirox, the time to reach peak (Tmax) is approximately 1.5-4 hours.

(1) The absolute bioavailability (AUC) of deferasirox tablets is 73.5±12.8%. Both the Cmax and AUC of deferasirox increase approximately linearly with dose after a single dose and under steady-state conditions.

(2) After multiple doses, the exposure level of deferasirox increased, with an accumulation factor of 1.3-2.3. The absolute bioavailability (AUC) of deferasirox orally dispersible tablets is approximately 70% of intravenous administration.

(3) When taken with a high-fat breakfast (fat content > 50% of total calories), the total exposure (AUC) increases approximately 1-fold; when taken with a standard breakfast, the total exposure (AUC) increases by approximately 50%.

(4) The bioavailability (AUC) of deferasirox is moderately increased (approximately 13-25%) when taken 30 minutes before a meal with a normal or high-fat meal.

2. Distribution: Highly bound to plasma proteins (about 99%), and almost exclusively bound to serum albumin. The steady-state distribution volume (Vss) in adults is 14.37±2.69 liters.