ribavirin information

http://en.wikipedia.org/wiki/Ribavirin

Pharmacokinetics

Ribavirin is absorbed from the GI tract probably by nucleoside transporters. Absorption is about 45%, and this is modestly increased (to about 75%) by a fatty meal. Once in the plasma, ribavirin is transported through the cell membrane also by nucleoside transporters.
Ribavirin is widely distributed in all tissues, including the CSF and brain. The pharmacokinetics of ribavirin is dominated by trapping of the phosphate form inside cells, particularly red blood cells (RBCs) which lack the enzyme to remove the phosphate once it has been added by kinases, and therefore attain high concentrations of the drug. Most of the kinase activity which converts the drug to active nucleotide form, is provided by adenine kinase. This enzyme is more active in virally infected cells.
The volume of distribution of ribavirin is large (2000 L/kg) and the length of time the drug is trapped varies greatly from tissue to tissue. The mean half-life for multiple doses in the body is about 12 days, but very long-term kinetics are dominated by the kinetics of RBCs (half-life 40 days). RBCs store ribavirin for the lifetime of the cells, releasing it into the body's systems when old cells are degraded in the spleen.
About a third of absorbed ribavirin is excreted into the urine unchanged, and the rest is excreted into urine as the de-ribosylated base 1,2,4-triazole 3-carboxamide, and the hydrolysis product of this, 1,2,4-triazole 3-carboxylic acid.

[carol411]

Thank you for posting this, Dave.  I was worried about virus hanging around in my brain once this is over.  Now I have hope that the ribaviron is kicking it to the curb everywhere it is hiding.  Good news!!

[spectda]

It's from wikipedia, but it was very simply put and hopefully accurate information.

[babs824]

a 30% boost by adding some healthy fat seems a worthwhile strategy. thanks for the info

[burned74]

Yea, Thanks so much for this post. I failed SOC 6 years ago and maybe part of it was that I eat a super low fat diet. My doc didnt say anything about taking Riba with fat.

Next time Vitamin D Teleprevir SOC with Riba lead in and Fat w/Riba

[Trish77]

I wouldn't exactly look at it that way.  It isn't that ribavirin was designed to be taken with fat.  I tend to think that the higher absorption of ribavirin when taken with high-fat foods is a value-added learned-later kind of thing.  So there's how ribavirin is supposed to perform and then there's giving it's performance a boost.  So I wouldn't exactly say that not taking it with fat was part of why SOC failed for you...but rather that taking it with fat might make it work better for you.  Get my drift?  

[nutpea]

Thank You for explaining this to us in such a good way. or @ least thanks for taking the time to find this information.

[Diane12855]

Very interesting info.

Looks to me like it does help to take it with a high fat meal. There are good fats though... I personally think it is very unwise to go the french fries and hamburgers route.

Diane

[Bali05]

the way to check for  Riba absorption is by looking at your HgB decline not by diet.
unfortunately a serum concentration labtest for Riba is not available so the only
way is by looking for it`s #1 toxicity namely hemolytic anemia.

People predose Riba to make sure to have enough onboard when INF does it`s first
strike , they don`t order extra fries for that purpose.

burned74: Do you remember your HgB levels from your first tx ?

On the flip side to all the fat lovers myself included , you will very likely gain weight if you stick with a high fat diet for a year and if you gain weight your Riba mg per bodyweight kg concentration will decrease.

This is why overweight people on flatdosed Riba are having poorer SVR rates.
Not because they do not consume enough fat.

[spectda]

This is a wikipedia page which explains some things simply about how ribavirin interacts with our bodies. This thread about riba water consumption/riba concentration thread, as well as many other threads about riba I have read on the forum have a lot of comments about adding some fat to help absorption of riba but not so much to make us fatter or unhealthy.

There is little doubt that the proper amount of ribavirin is essential to svr. the question is what is enough ribavirin. If every person absorbs ribavirin at different levels based on many more factors then their weight (kidney function for example) then weight based dosing doesn't make a lot of sense. If anemia is more then a crude indicator of riba absorption then why do a good amount of people still svr without becoming anemic, and why not just reduce riba when a person becomes anemic rather then give them procrit to keep the dose up.

Weight based dosing and anemia are only crude indicators of riba absorption for lack of testing true individual case riba absorption levels and what the real level should be to improve the chance of svr.

Since we are using such imprecise methods to calculate riba absorption the hammer method of clobbering people with very high dose riba and pre-dosing riba until their body cries uncle seems like the best way to go from my fairly unscientific perspective, but still it's a very crude way of determining what the correct level is and with high dosing comes more risks to the individual.

Since treatment does include a blood test to determine riba levels in each individual it leads me to believe that either it's too expensive and complicated to determine individual levels while on tx, there is a lot that is not known about how riba interacts with our body, or the governing authorities and medical guideline creators wants a simple table for prescribing medication even if it is only partially accurate and will sacrifice potential success for some individuals.

[spectda]

"Since treatment does include a blood test to determine riba levels"
meant to say:
Since treatment "does not" include a blood test to determine riba levels.

[spectda]

I guess if most doctors used the guidelines as a guide rather then a strict interpretation of how to treat we would be better off as individuals. Unfortunately many doctors that treat hep c do not understand a lot about the disease and treatment and are strict about following the guidelines instead of referring their patients to a specialist.

I have read that the success rates of experienced hepatologists treating hcv aggressively regarding medication levels/ blood cell levels have a much higher success rate then those doctors who don't understand where those lines are.

I really can't understand a person not going to a hepatologist to treat hcv or at least a GI doc who has a lot of hcv experience and knowledge. It's seems similar to using PCP/GP instead of an oncologist if you have cancer.  

[Bali05]

personally I would love to see the term SOC disappear.
treatment needs to be personalized
that would be a good start.
With all the new meds in the pipeline and different combinations and durations
there is hope :-)

[nygirl7]

Weight based dosing and anemia are only crude indicators ........"

you have to remember that even back as only when I started tx in 2005 - doctors were JUST finding out about weight based dosing then.  And that was Dr. J not some local town doc at that time!

I agree that the term SOC would be lovely to disappear as treatment being tailored to an individual definitely and postively has helped achieve SVR in greater numbers.  Whether it be weight based or extending or upping meds or taking an extra riba or PIs or whatever it is that makes it more specifically perfect for YOU - that is what needs to be done.  Thank God they have realized this in the past few years and are moving in the correct way now (the good ones anyway!).

I would not have made it to SVR had I not convinced my doc to tailor to me as he had never heard of such a thing. That was due to this forum of course so I am 100% on this side of any argument that might come up!

[Trish77]

"On the flip side to all the fat lovers myself included , you will very likely gain weight if you stick with a high fat diet for a year and if you gain weight your Riba mg per bodyweight kg concentration will decrease. "

Nobody is suggesting an overall high fat diet.  While I was pretty religious about eating a high-fat food with my ribavirin, I lost weight though not much while on treatment.  Once again, it's using some discretion as to what type of fat you include and how much.

[Bali05]

it adds up quickly. With high fat food for breakfast and high fat food dinner plus a usually less active lifestyle on tx.

I am just mentioning it because you always hear  fat,fat, fat
when I started taking Riba in the beginning I was gulping it down with heavy cream , certainly noticed the extra calories quickly and switched
to something more sensible.

[nygirl7]

Lord I think I am addicted to craving fats now.  I never ever was a fan of sugars or fats before treatment but during treatment I could have eaten sugar straight out of the sugar bowl.  In the 'olden' days I would never eat the things I am now - in fact we just got served BLTs with mayo on beautiful fresh rolls with crispy french fries for lunch here. Usually I'd take one bit and throw it out and eat something else but now.....I swear I cannot stop.Thank God i only took a half and three fries or I'd still be sucking it all in like a vaccuum.

It was not a good wagon train to get onto in the first place.  All my jokes about cheeseburgers and how great they are aside - I could always just eat a 1/4 of one and call it a day to satisfy my cravings but now........I'm like Lord stop me now cause I can't do it.

The combo of bad habits developing and cravings is wicked.  I wish  I never ever let myself fall into it because now to get rid of those calories from lunch I"m going to have to starve and work out. Totally not what I feel like doing at all.

This is a let the buyer beware story for real!

[nygirl7]

OH FYI someone just told me that their stepson found a shop that sells CANDY COATED BACON.

There ya go that should take care of all the ribavirin based fat needs anybody could ever think of.  Throw that down with a deep fried twinkie and oreo and consider the situation a rap ;)