Hi,

i want to ask about rituximab initial dose (infusion rate calculation).

for example:

BSA:2.0 M2

Rituximab: 375mg/m2 = 750 mg

total volume: 560 ml

drug concentration : 1.33mg/ml

i am gonging to start with 50mg /hr

please let me know the correct calculation ?

The 90-minute RITUXAN infusion rate :

Rituximab 500mg/m2 =1000mg

Total volume : 350ml

[*=left]20% of the total dose over the first 30 minutes
[*=left]80% of the total dose over the following 60 minutes
[*=left]how i can calculate it?
[*=left]Thank you for every one :)

Whoa. I haven't worked at many hospitals, but I've never seen Rituxan not in a 1:1 concentration. That's asking for someone to make a rate error with that concentration. Is there a specific reason your hospital doesn't use a 1:1 concentration?

thank you for your post

no reason, when i am ask them, they said there is a different protocol references and the concentration should be between 1mg - 4mg /ml

for the calculation i am using this formula

( dose rate X total volume) =rate ml/hr

rituximab dose

for the example up this is the answer:

50mg x 560ml = 37.3 ml/hr for 30 minutes

750mg

increase the rate to 100mg if no reaction

100mgX560ml = 74.6ml /hr

750mg

and you will continue increasing rate until 400mg/hr this is the maximum rate.

The 90-minute RITUXAN infusion in cycle 2 -6

20% of the total dose over the first 30 minutes

350ml _ 20% = 70ml you will give it over 30 minutes the rate should be 140ml/hr

80% of the total dose over the following 60 minutes

350ml _ 80% = 280 ml the rate over 60 minutes is 280ml/hr

i need some one to confirm if this is right calculation !!!!

We work with pharmacy to use the current infusion standards. For Rituxan, regardless of how many cycles, it is always 1:1 concentration, started at 50mg/hr and ramped up another 50mg/hr every 30 minutes until the max dose of 400mg/hr is reached. In 2 years we have had only three patients receive this med. All three have had an initial reaction. Two of the three have never been able to ramp up fast nor reach the optimal dose of 400mg/hr. Are you using a cardiac monitor with your infusions?

Rituxan can be done in 1mg/1ml, 2mg/1ml, or 4 mg/1ml depending on the desired concentration needed. All Rituxans that I have done have been 2 mg/1 ml concentration. Lets say your dose is 700 mg of Rituxin. You will start with a 500 cc bag. To get a 2 to 1 ratio, you then divide your 700 by 2. So you know that you will need a total volume (including medication that you will be adding) of 350 ml. Then you take out 150 ml to get 350 ml. Then you need to take the volume of the medication that you will be adding (70 ml in this case) from the 350 ml you have left. then you need to inject your medication 70 mls back in. If you do it this way you will have a 2mg/1ml concentration as is suggested.

We work with pharmacy to use the current infusion standards. For Rituxan, regardless of how many cycles, it is always 1:1 concentration, started at 50mg/hr and ramped up another 50mg/hr every 30 minutes until the max dose of 400mg/hr is reached. In 2 years we have had only three patients receive this med. All three have had an initial reaction. Two of the three have never been able to ramp up fast nor reach the optimal dose of 400mg/hr. Are you using a cardiac monitor with your infusions?

Exactly as written in "Cancer nursing: Principles and practice 7th edition" :)