Xeloda dosing and newbie questions. Please help

[Hopepray]

Hi members,

Firstly I want to thank you all for so many valuable information that I have received here. I ll keep you all in my prayers and hope you get well soon.

My first post here.

My mom has finished her 28 day neoadjuvant/preop chemoradiation. Her Xeloda daily dosing was 1500 mg for a whole day, she was told only weekdays but she did take on Sundays too. Radiation in total was 50.4 grays.

I am worried after reading many posts here on Xeloda dosing as most seem to have a 3000mg per day. I know it's weight dependant and she's around 68kgs or 150lbs.

Also , she has a waiting period of 4-6 weeks due to Covid19 before she can go get a PET CT to be reviewed for LAR. So the onc suggested that she can do two rounds of CapeOX in the meantime, would just two rounds help?

Thank you

[JJH]

Welcome to the Forum, and thanks for preparing a signature in advance.

You have 2 questions, but I'll start with the first one. To answer the first one, we need to know both your mother's weight and her height. This is needed in order to calculate Body Surface Area which in turn is needed to calculate the correct daily dose in mg. So, would you be able to provide both her height and weight? Also, could you specify how many Xeloda pills of which size she took in the morning, and how many Xeloda pills of which size she took at night?

Thank you.

[Hopepray]

Welcome to the Forum, and thanks for preparing a signature in advance.

You have 2 questions, but I'll start with the first one. To answer the first one, we need to know both your mother's weight and her height. This is needed in order to calculate Body Surface Area which in turn is needed to calculate the correct daily dose in mg. So, would you be able to provide both her height and weight? Also, could you specify how many Xeloda pills of which size she took in the morning, and how many Xeloda pills of which size she took at night?

Thank you.

Thank you JJH
She is around 150lbs and 5 feet 3 inches. She used to take 2 pills in the morning and one at night all of 500 mg. She was told she may skip taking Sat and Sun but she did take on Sundays as well.

[sdino]

As JJH said, I believe one driving factor is the weight of the person. My Wife started out with 3500 mg/day. But was reduced to 3000 mg/day due to hand/foot syndrome. She stayed on Xeloda+Avastin from Aug 2018 to Feb 2019 with slight progression. Near Feb 2019, we could tell progression was getting slightly worse.

[sdino]

As JJH said, I believe one driving factor is the weight of the person. My Wife started out with 3500 mg/day. But was reduced to 3000 mg/day due to hand/foot syndrome. She stayed on Xeloda+Avastin from Aug 2018 to Feb 2019 with slight progression. Near Feb 2019, we could tell progression was getting slightly worse.

[Hopepray]

As JJH said, I believe one driving factor is the weight of the person. My Wife started out with 3500 mg/day. But was reduced to 3000 mg/day due to hand/foot syndrome. She stayed on Xeloda+Avastin from Aug 2018 to Feb 2019 with slight progression. Near Feb 2019, we could tell progression was getting slightly worse.

Thx sdino and jjh
@sdino I wish speedy recovery for your OH and will keep you in my prayers.


My replies come late as every reply of mine should be approved.


My mom is 150lbs and 5.3 ft as I noted in my previous reply which I am not sure has been approved yet.

[JJH]

... I am worried after reading many posts here on Xeloda dosing as most seem to have a 3000mg per day. I know it's weight dependant and she's around 68kgs or 150lbs...

...My mom is 150lbs and 5.3 ft as I noted in my previous reply which I am not sure has been approved yet.

...She is around 150lbs and 5 feet 3 inches.

Thank you for the update. I will assume that your mom is 5 feet 3 inches and not 5.3 feet. (5.3 feet is more like 5 feet 4 inches.)

With this information we can calculate the correct dose for your mom.

First, let me say that the standard Xeloda dose for use with neo-adjuvant radiation is usually 825 mg/m2. (This is different from the standard dose used in Capeox (Xeloda + oxaliplatin), and it is different from the standard dose that sdino's wife had under her regimen of Xeloda +Avastin. In these matters you have to pay very close attention to the particular regimen that Xeloda is being used in.) Your mom was on the regimen "Neoadjuvant Capecitabine / Radiation Therapy"

Here is a table showing the standard


There is one thing in this table that is very, very important. It is the acronym bid, which in Latin means "twice a day". So, this standard dose of 825 mg/m2 needs to be taken twice a day (i.e., morning and evening)

With your mom's height and weight we can use a BSA calculator to get her Body Surface Area. Then in the second part of the calculator we can calculate how many milligrams of Xeloda your mom should have taken in the morning and how many in the evening.

By using a height of 63 inches and a weight of 150 pounds, the calculator will show her Body Surface Area. (Note: In the on-line form you have to first click on the down-arrows to change the height units from centimeters to inches, and the weight units from kilograms to pounds before you click on "Calculate Body Surface Area". Also, you have to enter 825 in the Drug dosage/M2 box so that the calculator wil do the conversion.)

Once you have done all this and clicked on the "Calculate" button you will see the Results:

BSA = 1.71
Dose = 1410.75 bid

In other words, the correct morning dose is 1410.75 and the correct evening dose is 1410.75, for a total daily dose of 2821.50 mg.

To approximate 1410.75 with the available pill sizes of 500 mg and 150 mg, the pharmacist might prescribe 2 large pills and 3 small pills every morning and every evening. Or he might decide to do the approximation in a different way.There is no way to come up with exactly 1410.75mg with only 500 mg and 150 mg pills.

BSACalculator
https://globalrph.com/medcalcs/body-surface-area-bsa/

So, if these calculations are correct, then your mom received only about half of the Xeloda that she should have received. If this is true, I don't know why. Maybe the doctor or pharmacist wrote the prescription as "1,500 mg. bid" but didn't explain what bid meant.

You need to have a professional look into this soon, before they start the CAPEOX cycles, because if they did the calculations wrong for the 5 weeks of chemo/radiation they might make the same kind of mistake in the CAPEOX dosing.

Let us know what you find out.

Thank you.

[Hopepray]

... I am worried after reading many posts here on Xeloda dosing as most seem to have a 3000mg per day. I know it's weight dependant and she's around 68kgs or 150lbs...

...My mom is 150lbs and 5.3 ft as I noted in my previous reply which I am not sure has been approved yet.

...She is around 150lbs and 5 feet 3 inches.

Thank you for the update. I will assume that your mom is 5 feet 3 inches and not 5.3 feet. (5.3 feet is more like 5 feet 4 inches.)

With this information we can calculate the correct dose for your mom.

First, let me say that the standard Xeloda dose for use with neo-adjuvant radiation is usually 825 mg/m2. (This is different from the standard dose used in Capeox (Xeloda + oxaliplatin), and it is different from the standard dose that sdino's wife had under her regimen of Xeloda +Avastin. In these matters you have to pay very close attention to the particular regimen that Xeloda is being used in.) Your mom was on the regimen "Neoadjuvant Capecitabine / Radiation Therapy"

Here is a table showing the standard


There is one thing in this table that is very, very important. It is the acronym bid, which in Latin means "twice a day". So, this standard dose of 825 mg/m2 needs to be taken twice a day (i.e., morning and evening)

With your mom's height and weight we can use a BSA calculator to get her Body Surface Area. Then in the second part of the calculator we can calculate how many milligrams of Xeloda your mom should have taken in the morning and how many in the evening.

By using a height of 63 inches and a weight of 150 pounds, the calculator will show her Body Surface Area. (Note: In the on-line form you have to first click on the down-arrows to change the height units from centimeters to inches, and the weight units from kilograms to pounds before you click on "Calculate Body Surface Area". Also, you have to enter 825 in the Drug dosage/M2 box so that the calculator wil do the conversion.)

Once you have done all this and clicked on the "Calculate" button you will see the Results:

BSA = 1.71
Dose = 1410.75 bid

In other words, the correct morning dose is 1410.75 and the correct evening dose is 1410.75, for a total daily dose of 2821.50 mg.

To approximate 1410.75 with the available pill sizes of 500 mg and 150 mg, the pharmacist might prescribe 2 large pills and 3 small pills every morning and every evening. Or he might decide to do the approximation in a different way.There is no way to come up with exactly 1410.75mg with only 500 mg and 150 mg pills.

BSACalculator
https://globalrph.com/medcalcs/body-surface-area-bsa/

So, if these calculations are correct, then your mom received only about half of the Xeloda that she should have received. If this is true, I don't know why. Maybe the doctor or pharmacist wrote the prescription as "1,500 mg. bid" but didn't explain what bid meant.

You need to have a professional look into this soon, before they start the CAPEOX cycles, because if they did the calculations wrong for the 5 weeks of chemo/radiation they might make the same kind of mistake in the CAPEOX dosing.

Let us know what you find out.

Thank you.

Thanks JJH, the cap pills given were 500mg and the doc told us 3 in the morning and 2 in the night. Sorry for not being clear before and yes this was given as a radio sensitising agent we were told:

So would you think that in a neo-adjuvant setting, as a radio sensitizing agent, Xeloda dose of 1500 mg for a full day that was given to my mom falls close to the standard 825mg/m2 twice daily. Which is 1650mg for a full day.

By Dose = 1410.75 bid did you mean this for a proper chemotherapy regimen like if we were to start with the CapeOX cycles?

PS: There were no other pills during 28 days chemoradio except for some antibiotics and a supplement tablet(Sporolac) with different strains of good bacteria to help with stomach issues.

[JJH]

Thanks JJH, the cap pills given were 500mg and the doc told us 3 in the morning and 2 in the night. Sorry for not being clear before and yes this was given as a radio sensitising agent we were told:

So would you think that in a neo-adjuvant setting, as a radio sensitizing agent, Xeloda dose of 1500 mg for a full day that was given to my mom fall close to the standard 825mg/m2 twice daily. Which is 1650mg for a full day.

If your mom took 3 in the morning and 2 at night, then the full-day Xeloda dose she was receiving was 5 x 500mg =2,500 mg, not 1,500mg. Why do you say 1 500 mg? Where did that come from? The required full-day dose for her is 2,821.5 mg, so 2,500 mg is a little short of that.
.

By Dose = 1410.75 bid did you mean this for a proper chemotherapy regimen like if we were to start with the CapeOX cycles?

No, not at all. The CapeOX regimen has a completely different dosing schedule for Xeloda. For your mom, theoretically it would be 1,710 mg in the morning and 1,710 mg at night for a total daily dose of 3,420 mg. This would be more than she was taking during radiation because CapeOX is a full therapeutic regimen, not just a radiosensitization regimen.

The pharmacy dosing for your mom's CapeOX regimen is found in Table 2 of the document below. With a BSA of 1.71 and a total required daily dose calculated as 3,420 mg, the closest match, given availability of only 500 mg and 150 mg tablets is found on the line for BSA 1.67 -1.78 : Thus, the prescribed dose she would be given by the pharmacist is: 1,750 mg bid, or 3,500 mg total daily dose. The prescription will consist of 2 large (500 mg) tablets and 5 small (150 mg) tablets taken both in the morning and in the evening.

https://www.ema.europa.eu/en/documents/product-information/xeloda-epar-product-information_en.pdf

Side effects of XELOX (CAPEOX) regimen
https://coloncancersupport.colonclub.com/viewtopic.php?f=1&t=59287&p=469490#p469490

[Hopepray]

Thanks JJH, the cap pills given were 500mg and the doc told us 3 in the morning and 2 in the night. Sorry for not being clear before and yes this was given as a radio sensitising agent we were told:

So would you think that in a neo-adjuvant setting, as a radio sensitizing agent, Xeloda dose of 1500 mg for a full day that was given to my mom fall close to the standard 825mg/m2 twice daily. Which is 1650mg for a full day.

If your mom took 3 in the morning and 2 at night, then the full-day Xeloda dose she was receiving was 5 x 500mg =2,500 mg, not 1,500mg. Why do you say 1 500 mg? Where did that come from? The required full-day dose for her is 2,821.5 mg, so 2,500 mg is a little short of that.

Sorry she was taking 2 in the morning and 1 in the night-confirmed in the prescription. I did a big typo in last reply. The total is right in a day was 1500mg. As a dose for radio sensitizing agent isn't that enough dose, I know the last table you put says 825mg/m2 bid. Which makes it 1650mg in the whole day?

By Dose = 1410.75 bid did you mean this for a proper chemotherapy regimen like if we were to start with the CapeOX cycles?

No, not at all. The CapeOX regimen has a completely different dosing schedule. For your mom, it would be 1,710 mg in the morning and 1,710 mg at night for a total daily dose of 3,420 mg. This is more than she was taking during radiation because CapeOX is a full therapeutic regimen.

Thank you

[JJH]

Sorry she was taking 2 in the morning and 1 in the night-confirmed in the prescription. I did a big typo in last reply. The total is right in a day was 1500mg. As a dose for radio sensitizing agent isn't that enough dose, I know the last table you put says 825mg/m2 bid. Which makes it 1650mg in the whole day?

No, absolutely not! A protocol dose of 825mg/m2 bid does not make 1650mg for the whole day. It makes 1650mg/m2 for the whole day. A prescription dose of 1650mg is not at all the same thing as a protocol dose of 1650mg/m2. The units of measurement are different.

Protocol doses (phrased in terms of meters squared (m2) of body surface area) need to be converted to to prescription doses by multiplying the protocol doses by the patient's body surface area.

In your mom's case, the targeted prescription dose for the whole day would be

(protocol dose) x (body surface area) =

1650mg/m2 x 1.71m2 = 2,821.5mg = targeted whole day prescription dose.

The actual prescription dose, in round numbers, would be something similar to this and would be approximated by an appropriate mixture of 500mg pills and 150mg pills. The actual prescription would be a whole number ending in zero because both 500 and 150 are whole numbers, and when the pharmacist comes up with the best pill count to closely match the targeted prescription it will also be a whole number and it will end in zero.

Thus, the whole day target prescription dose for your mom, 2,821.5mg is just under 3,000mg per whole day. What your mom actually received as an actual prescription (1,500mg per whole day) is only about half of what the standard protocol recommends.

[JJH]

Duplicate post

[roadrunner]

Sorry, didn’t she get 2500 mg. per day? I think it said 3 in the morning, 2 at night. If so that’s 5 x 500, no? Pretty standard for CRT for a person that size I think. Unless I’m missing something, which could of course be the case.

[roadrunner]

Never mind. I re-read and realized that was a typo. Apologies.

[JJH]

Your mom could contact her oncologist on Monday to seek clarification on these two issues:

1. Why did the oncologist recommend Xeloda dosing at half the protocol-recommended level during neoadjuvant chemo/radiation? He should be able to explain his rationale for doing this. Normally the low 50% dose level is reserved for fragile patients who cannot tolerate full Xeloda dosing, such as patients who have renal insufficiency and are in danger of renal failure. Ask him to explain his reasons.

2. Why is the oncologist recommending a 6-week short course of neoadjuvant CapeOX in tandem with the 5 week neoadjuvant chemo/radiation course already completed? He should be able to explain why he wants to do this. This type of addition to the neoadjuvant chemo/radiation standard is not mentioned in the NCCN standard of care for rectal cancer.

Meanwhile, between now and Monday you could help your mom by drafting a checklist as well as a transcript of possible questions to ask in a teleconference with the oncologist.

Good luck!