Juggling the anti nausea meds

Am out of my five days of anti-nausea drugs - didn't take the last domperidone in a bid to rid myself of some very stomachy side effects. Seem to have got away with that and ginger tea is helping with lingering nausea now. 

Now need to gather myself to argue for best combination next time. Aim - get through the night without feeling sick. What can I find out that makes sense to me? Thank you netdoctor.co.uk, drugs.com, drugbank.ca, medscape.com, medicines.org.uk, wikipedia and sorry for the inevitable oversimplification.

There is a brain area called the chemoreceptor trigger zone (CTZ). It's chock-a-block with nerve cells and different chemical and neurotransmitter receptors so it can respond to: (1) nerve messages which get sent from the gut when irritants are detected: and (2) directly to some substances in the blood e.g. chemotherapy poisons. It reacts by sending out the shadowy Substance P (a cover identity for neurokinin-1) which activates neurokinin-1 receptors in the vomiting centre in the brain (next-door neighbour to CTZ). Vomiting centre messages the gut muscles, and bingo! 

The drugs in the armoury are:

Domperidone - blocks dopamine receptors in the upper end of the gastrointestinal system with the ultimate result of speeding up passage of food through the stomach, thus getting it safely out of the way of being thrown up. It also blocks dopamine receptors in the CTZ, which prevents messages being sent to the vomiting centre and in this way, reduces nausea as well as vomiting. Good. Half life = 7 hours.

Dexamethasone - happy and cheap find for treating a certain stage of Covid-19  and many other things - also helps with nausea and vomiting of chemotherapy, but why is not known... There's a suggestion that it may work better in women with history of motion sickness - me! me! me! And, as I've said before, it makes you feel better, possibly via release of endorphins. Half life = 36-54 hours. Downside is that that feeling better angle extends to wakefulness.

Ondansetron - works around 5-hydroxy tryptamine a.k.a. 5HT a.k.a. serotonin. I thought serotonin was a good thing, but it appears that chemotherapy (amongst other things - radiotherapy, surgery and !!??chocolate??!!) can cause serotonin to be released, presumably in a bad way. This serotonin acts on 5HT3 receptors in  brain and gut which sneak off messages to the vomiting centre again with predictable results. Ondansetron blocks those 5HT3 receptors. Half life = 3-4 hours which doesn't sound very promising for getting through the  night. Interestingly, even before I looked this up, I'd gone right off my morning hot chocolate...

Aprepitant - the extra anti-nausea drug I had last time - acts directly by blocking the neurokinin-1 receptors in the vomiting centre. Half life = 9-13 hours - that sounds good, but last time they gave it to me in the mornings, which probably won't do so much for the night time.

There could also be a problem with ondansetron and domperidone together which is what I ended up with this time after the poor start: with domperidone is speeding up stomach emptying and ondansetron is causing constipation ... La Grande Bouffe doesn't do it justice. 



Comments

  1. Ali16 August 2020 at 07:16

    That all sounds a bit complicated! Hope you can work out the right drug combination for the next session. A xx

    ReplyDelete
  2. Bruv18 August 2020 at 09:01

    This comment has been removed by the author.

    ReplyDelete

Post a Comment

Popular posts from this blog

The support hammock

Image
17.4.18 I feel as if I'm lying about in a comfy hammock made of people linked together caring for me and holding me up. It was a bit hairy getting into the hammock, and it's a long way above terra firma but now I'm there I feel pretty relaxed. How horrible it must be to be in this situation at an older age, with fewer friends left and family maybe elsewhere. There are the professionals including a little team of Clinical Nurse specialists (CNSs) who are pretty much at the end of a phone. There's the Macmillan Advice and Info centre, also at the end of a phone, but with a physical presence in the UCLH Macmillan Cancer Centre. There's a 'Living Room' there - at least a couple of meanings wrapped up in that  name I think - where you can hang out, and make tea or coffee without having to wash your mug up afterwards - just put it in the dishwasher! Very useful when you're there for things with long waits, although I now have the Grant Museum of Zo...
Read more

BACK ON THE JUICE - 6 JULY 2023 - ATOV TRIAL CYCLE 2

 So, I'm Patient 2 on the Atov trial, and have been randomised onto the adaptive treatment arm. This means that I start off with three cycles of carboplatin at three-weekly intervals. First one was on 15 June - 500mg by infusion as usual, followed by the expected days of sick tiredness, gradual improvement, then back to my new normal which is sadly not as good as the old normal.  I was told not to expect a sufficient reduction in Ca 125 after this to allow a reduction in dose so soon. This managed my expectations nicely, but in fact Ca125 had dropped by 55% - memo to self to get the actual numbers - so I'm in today having an 80% dose of carboplatin (400mg) - memo to self to ask for the dose calculation formula. Same dose of anti-sickness pre-meds and think I'll be sent home on usual doses of anti-sickness post-meds but I'm very (self) interested to see if the side effects are less bad on this only slightly lower dose of carboplatin, or if they perhaps pass more swiftly....
Read more

Kicking off

Image
Dearest readers. I don't have enough thanks for all of you who have taken an interest in what's been going on with me. Your presence, distractions, words, cards, flowers, messages have given me a fantastic sense of support. I'm sorry that in return I haven't always been able to get back to everyone and I can't remember what I've said to whom and end up boring endlessly about the same things. So a leap into the 20th century seemed like a good idea for keeping anyone who wants to know informed - and maybe give me an outlet for venting spleen (while I've still got one). My apologies if the latter means there is too much information. And before I continue - thank you to whoever sent the mystery flowers...I haven't been able to track you down, but it said 'With love x' on the tag How did I get here? On 20th January, I cycled energetically to GP with 'a change of bowel habit'. GP found lump in my belly - referred me for colonoscopy. I r...
Read more