Chemo protocols and cyclophosphamide dosing

RE: Chemo protocols and cyclophosphamide dosing

Kate Richardson — Thu, 10 May 2018 21:52:02 GMT

Having done a handful of chemo cases over the past few years, and initially used to order the vincristine and do it myself and then latterly started using Chemopet, I would never go back to the diy method. Yes it's relatively easy, but even if you're comfortable with the risk yourself, I always had my assistants to think of, and it does put some pressure on you, which is the last thing you want when administering. Since using Chemopet that worry almost disappeared- still there, but significantly less. Less worry I had the dose wrong, less worry about spillage/aerosolisation(?) and less worry that I had forgotten part of the equipment. Wouldn't go back.

RE: Chemo protocols and cyclophosphamide dosing

Richard Carter — Thu, 10 May 2018 17:39:51 GMT

Nova labs make up an oral liquid cyclophophamide in various strengths so can accurately determine dosage rather than try deal with 50mg tablets +44 (0) 116 223 01 00

RE: Chemo protocols and cyclophosphamide dosing

Jenny Harris — Thu, 10 May 2018 07:09:50 GMT

Is the concern not more because it is aerosolized when drawing up as it’s a liquid?

RE: Chemo protocols and cyclophosphamide dosing

Rob Loxley — Wed, 09 May 2018 23:47:25 GMT

[quote user="Ashlea"]I think we're going to have to go with Chemopet rather than vincristine vials as it's currently out of stock with our suppliers.[/quote]

We currently use Munro Vet supplies:

Vincristine INJ 2mg/2ml	Vin184	1 x 2ml Vial	£8.05

Vincristine INJ 2mg/2ml

Vin184

1 x 2ml Vial

£8.05

Chemopet (who clearly provide a very different service, I know) charge £13.65 per ml plus £20 dispensing fee plus £12.50 delivery.

[quote user="Beats"]In the hope there's no such thing as a stupid question... why is vincristine so dangerous compared to other substances in the clinic? And is there some sort of measure of how hazardous it is
I'm rather going off using it altogether, but don't want to be avoiding it on superstition so checking the facts behind the fear.[/quote]

Of the COP drugs, cyclophosphamide is reported as the more carcinogenic http://monographs.iarc.fr/ENG/Classification/ClassificationsAlphaOrder.pdf (along with azathioprine, chlorambucil and ciclosporin which are all fairly regularly dispensed by vet practices). So the evidence suggests we should worry more about all of those than vincristine.

We also worry about potential fetotoxic effects, particularly employing lots of people who fall pregnant (likewise your comment on Alizin stands); and local tissue reactions if accidentally injected (likewise other drugs we regularly use).

RE: Chemo protocols and cyclophosphamide dosing

Beats — Wed, 09 May 2018 22:15:28 GMT

In the hope there's no such thing as a stupid question... why is vincristine so dangerous compared to other substances in the clinic? And is there some sort of measure of how hazardous it is (I assume there must be, as otherwise how does one know when excreted levels in patient have reached safe levels etc.)?

Is it because it is inherently highly hazardous to us (i.e. more hazardous than bleach/immersion oil etc if spashed in eyes / skin, more hazardous than cyclophosphamide/azathioprine/ciclopsporin etc if comes in contact with skin or accidently ingested etc.)

Or is it because it is hazardous by means of being connected to a needle and accidental self-injection (in which case is it clearly more hazardous than cylap vaccine, detomidine, micotil and other self-injection nasties, or alizin, prostaglandins etc re pregnancy, or the numerous other teratogens).

Finally, is it an issue purely of direct toxicity, or are there concerns that if one develops neoplasia having been exposed to vincristine in minute amounts on an irregular basis it could lead to resistance to that drug in your own treatment?

I'm rather going off using it altogether, but don't want to be avoiding it on superstition so checking the facts behind the fear.

RE: Chemo protocols and cyclophosphamide dosing

Ashlea — Wed, 09 May 2018 21:27:49 GMT

Thanks everyone, it's a couple of years since I've had a chemo case so it's interesting to hear how others are dealing with them. I think we'll likely go high-dose COP but as we have the immunohistochemistry results pending and the owners going on holiday we'll wait for that rather than leaping straight in.

I think we're going to have to go with Chemopet rather than vincristine vials as it's currently out of stock with our suppliers. I've done DIY vincristine dosing quite happily before but given the practice circumstances it's probably not worth the additional risk.

RE: Chemo protocols and cyclophosphamide dosing

Rob Loxley — Wed, 09 May 2018 20:03:36 GMT

We've used Chemopet and the service is good (as long as the lying couriers actually turn up on time...), but for COP it adds significantly to the cost compared to DIY, and these already are cases that push financial limits, and I'm not convinced you can't do COP adequately safely yourself?

RE: Chemo protocols and cyclophosphamide dosing

Thomas Johnson — Wed, 09 May 2018 17:05:42 GMT

[quote user="Martin Atkinson"]

[quote user="Thomas Johnson"]....though the syringe is self-sealing so you can't push any liquid out unless it is attached to a Luer connector, but there is no similar seal on the end of the tubing attached to the i/v catheter.[/quote]Not sure if I'm misunderstanding this but this is why I use a 3 way tap so you can flush without removing the syringe containing the chemo agent and chuck the whole assembled unit straight into the cytoxic waste bin when you've disconnected from the IV cannula.

[/quote]

This is why I prefer the Phaseal system to the one that comes with drugs from Chemopet. Phaseal works in a similar way to a 3 way tap, but because of the way everything locks together, and with the use of the vial protectors, there's no risk of spillage and you don't need to use a needle (other than the catheter stilette of course!).

http://www.cave-vet-specialists.co.uk/phaseal

RE: Chemo protocols and cyclophosphamide dosing

Martin Atkinson — Wed, 09 May 2018 15:38:57 GMT

RE: Chemo protocols and cyclophosphamide dosing

Thomas Johnson — Wed, 09 May 2018 15:14:14 GMT

[quote user="Anthony Dennison"]I would really recommend using chemopet - order online for next day delivery, all injectables come pre-made in a syringe with a phaseal system attached to it.[/quote]

I agree that Chemopet is very good, but the system they send for giving it is not Phaseal, and the downside compared to a Phaseal C80 Y-site is that you have to disconnect the syringe that contained the chemotherapy to re-attach the flush, though the syringe is self-sealing so you can't push any liquid out unless it is attached to a Luer connector, but there is no similar seal on the end of the tubing attached to the i/v catheter.

RE: Chemo protocols and cyclophosphamide dosing

Sarah Wheadon — Wed, 09 May 2018 14:21:22 GMT

Another vote for Chemopet - great service.

RE: Chemo protocols and cyclophosphamide dosing

Ashlea — Wed, 09 May 2018 14:05:29 GMT

Maybe I'm better to wait until we know whether it's B or T cell before finalising the plan then. I've used lomustine before but only as a rescue. The other wrinkle I've just discovered is that the owners have a 2-week holiday booked starting in 2 weeks which is going to mess up our protocols completely. As much as I don't want to delay it'll give us time to get everything together.

RE: Chemo protocols and cyclophosphamide dosing

Rob Loxley — Wed, 09 May 2018 13:55:57 GMT

[quote user="Ashlea"]not sure whether it's B or T cell yet[/quote]

worth finding out as there seems to be a move towards different regimes for T-cell e.g. LOP (lomustine rather than cyclophosphamise) or LOPP

we have used doxorubicin in practice with the closed system from Chemopet, but generally would refer off for doxorubicin protocols (e.g. CHOP)

Doing COP we go for high-dose; as well as using standard tablet sizes it can be easier to monitor for cyclophoshamide side effects (eg neutropenia) than a more continuous regime.

We don't tend to use a closed system for vincristine injections, but that is a local risk assessment. ECVIM guidelines on reducing cytotoxic exposure are at https://www.ecvim-ca.org/guidelines

RE: Chemo protocols and cyclophosphamide dosing

Anthony Dennison — Wed, 09 May 2018 13:55:55 GMT

I would really recommend using chemopet - order online for next day delivery, all injectables come pre-made in a syringe with a phaseal system attached to it. We've currently got 2 dogs with lymphoma on a CHOP protocol and have previously been managing post-op high grade MCTs with chemo from them too.

Really easy to order, they're always very helpful with advice and they always ask for updates on the cases.

RE: Chemo protocols and cyclophosphamide dosing

Martin Atkinson — Wed, 09 May 2018 13:43:07 GMT

I confess to being a bit cavalier about chemo in the past: I personally drew up the injectables so the only person who was handling them was me (was happy to use Doxorubicin and cis-platin as well) over the tub table and used normal syringes but always gave IV through a cannula and 3 way tap with the flush already connected. Every dose and connection triple checked before administration. I have been happy to use 50 mg cyclophosphamide tablets but adjusted the frequency pro rata to get the same dose over a 2 week period even in cats without issues. Goes without saying everyone involved wore aprons, masks, goggles, gloves and long sleeves and barrier nursing type protocol for cleaning cages handling patients if given cis-platin.

Never had an incident but I realised that this wouldn't wash if there was a one. So I will probably go for the Phaseal system and order individual doses in future. It just adds to the cost of an already expensive procedure.

RE: Chemo protocols and cyclophosphamide dosing

Ashlea — Wed, 09 May 2018 12:46:30 GMT

[quote user="Thomas Johnson"]I like the Phaseal system, but recently because we couldn't get any vincristine from our wholesaler I've been ordering it as individual doses from https://chemopet.co.uk/ who supply it drawn up in syringe with a suitable connector to the i/v catheter and some flush.[/quote]

Thank you - that might make things easier for us as we have a few people in the practice and although they won't be anywhere near this anything we can do to reduce our risks is good!

[quote user="Jenny Boyd"]

Ashlea I am presuming you’re talking about high grade multi centric lymphoma? as far as I’m aware you need to do high dose COP, I’ve spoken with an oncologist before and they said they don’t even know why low dose is in the Formulary. We normally use the phaseal system but make sure everyone is happy with that. Otherwise you could see if owner wanted to refer for chop?

if it’s a different type of lymphoma then ignore the above![/quote]

Multicentric, yes, we removed the spleen as it had a discrete mass which was growing quickly and causing considerable pain but the dog also has enlarged lymph nodes. That's interesting to hear about the high-dose COP, I think my colleague has discussed CHOP with the clients but elected for COP. High-dose would mean we didn't have to get the cyclophosphamide put into capsules so may be worth us looking at.

RE: Chemo protocols and cyclophosphamide dosing

Jenny Harris — Wed, 09 May 2018 12:30:43 GMT

if it’s a different type of lymphoma then ignore the above!

RE: Chemo protocols and cyclophosphamide dosing

Thomas Johnson — Wed, 09 May 2018 11:55:41 GMT

[quote user="Ashlea"]What administration systems are the best for vincristine injections? We've been looking at the PhaSeal system but are there other good systems which can be ordered from a regular supplier? [/quote]

I like the Phaseal system, but recently because we couldn't get any vincristine from our wholesaler I've been ordering it as individual doses from https://chemopet.co.uk/ who supply it drawn up in syringe with a suitable connector to the i/v catheter and some flush.

[quote user="Ashlea"]The cyclophosphamide dose for low dose COP will be around 17.5mg so I'm wondering whether it's best to go for high-dose COP, whether to alter the frequency of cyclophosphamide administration or whether to go down the route of getting the correct dose put into capsules? If capsules are worth doing can anyone recommend a company to do this? [/quote]

I've ordered cyclophasphamide capsules in the sizes I need from http://www.specialslab.co.uk/serv56-Unlicensed-Veterinary-Medicines,-Vet-Specials.html