Cyclophosphamide availability

[Avena]

Taking cyclo once in a month for 6 months is one thing, taking it multiple times is much more toxic.

What is most important here - the number of times or the interval? Will the 6 dosages stretched over a year (infusion every second month) be less or more toxic in the long term?

Are there any theories on where the "limit" is before increasing the risk of long time damages like Bladder Cancer? I think I've heard someone mention using IV Saline before/after to flush trough/limit the time in the bladder, is this an common prevention action?

 

[deleder2k]

I think the total accumulated is important but I'm no doc

 

[jpcv]

What is most important here - the number of times or the interval? Will the 6 dosages stretched over a year (infusion every second month) be less or more toxic in the long term?

Are there any theories on where the "limit" is before increasing the risk of long time damages like Bladder Cancer? I think I've heard someone mention using IV Saline before/after to flush trough/limit the time in the bladder, is this an common prevention action?

usualy once every 4 weeks is the ususal schedule.
we almost never use cyclo for more than 6 months in cancer patients and bladder cancer is not a problem with this schedule.
There is no need to use a large volume of IV Saline in the 600 mg/m2 schedule, but if bigger doses are used, it´s a good option, along with the use of bladder protetant Mesna.
Reumathologists use it for longer times, I supose that @Jonathan Edwards has more experience regarding longer scedules.

 

[Jonathan Edwards]

What is most important here - the number of times or the interval? Will the 6 dosages stretched over a year (infusion every second month) be less or more toxic in the long term?

Are there any theories on where the "limit" is before increasing the risk of long time damages like Bladder Cancer? I think I've heard someone mention using IV Saline before/after to flush trough/limit the time in the bladder, is this an common prevention action?

I don't think there is any 'limit' to be honest. My understanding is that every drop of cyclophosphamide is a risk and the more you have over a period the greater the risk. The risk is long term - the cancer may appear years later - and in the original regimens used in the 1960s the rate of cancer was horrendous. I have used very little cyclophosphamide but have had three patients with bladder or renal cancer. That could be a coincidence but I stopped using it for good in 2002.

 

[deleder2k]

I don't think there is any 'limit' to be honest. My understanding is that every drop of cyclophosphamide is a risk and the more you have over a period the greater the risk. The risk is long term - the cancer may appear years later - and in the original regimens used in the 1960s the rate of cancer was horrendous. I have used very little cyclophosphamide but have had three patients with bladder or renal cancer. That could be a coincidence but I stopped using it for good in 2002.

Do you remember the dosing? I think Fluge and Mella have used 600-700 mg/m2. I think that is a common dosage for breast cancer. Once every month for 6 months. They are experiencing that patients report more severe side effects compared to what cancer patients experience. I think they are trying to lower the dosage to see if the improvement in symptoms is just as good.

The study is now completed. I can't wait for the results of the cyclo study. I am sure psychobabblers (as prof E) refers to them will say that the study is BS since patients was not blinded. Nevertheless: it will be interesting.

Then 1H 2018: Rituximab study published in PlosONE. Or do they hit the jackpot and publish in a major journal? Perhaps they are aiming where you aimed, dr. Edwards. I guess no one can't limit themselves if NEJM accepts it?

 

[Avena]

Thank you for your answers. I assume Desmopressin (for OI) would increase the risk and would have to be discontinued before starting Cyclo? @jpcv

 

[jpcv]

Thank you for your answers. I assume Desmopressin (for OI) would increase the risk and would have to be discontinued before starting Cyclo? @jpcv

Sorry, I didn´t understand, @Avena , risk of what? Bladder cancer?

 

[Kati]

Thank you for your answers. I assume Desmopressin (for OI) would increase the risk and would have to be discontinued before starting Cyclo? @jpcv

I do not see any contraindication between Desmo and Cyclo, however the physician prescribing Cyclo would be able to tell you. As far as I know no physician would prescribe Cyclo for ME outside of a clinical trial. We are waiting for the publication and then waiting for the Rituximab phase 3 study results in 2018. Jumping the gun could have serious consequences.