How to calculate weight based Riba dose?

A couple of posts below, someone asked how to calculate weight based Riba.  A lot of recent posts state that it is important and most of us don't know how to figure out if we're on a high, low, or whatever level of Riba.

Can someone provide the formula (for pounds and for kilograms)?

JmJm once calculated mine.  Thanks.

[GrandOak]

See:

http://hepatitis-central.com/mt/archives/2004/12/weightbased_tre.html

[GoofyDad]

For weight based dosing, the typical ranges are between 13.3 and 15.5 or so mg per kg of body weight. Generally, I think you want to be over 15. Divide your weight in lbs by 2.2 to get kg.

165/2.2 = 75kg
75kg X 15.5 = 1,162.5 mg

or supposing you were taking 800 mg for 165 lbs:

165/2.2 = 75kg
800kg/75kg = 10.6 (quite a bit outside of our 13.3 - 15.5 range)

[mkeela]

That is really scary as I am pretty fat at 216lbs. I am only taking 800 riba a day...should I speak to doc about that? How about 180 Pegasys? Im only 5'1" (round lil porker since my 30's..lol)and also, I have heard that fat folks don't respond to tx as well...IS THAT TRUE???? Freakin' out now again...mkeela

[Kalio1]

Yes that is true about weight hindering SVR a bit. And yes if I was you I would definatey talk to your doctor about that riba amount ask him what he is basing the dosage on?

[copyman]

very good post, this is also of interest to me as my doc wrote the rx for 800mg of riba and i weigh 200lbs. some have said this seems low for me? i should be starting tx soon but i think i need to ask the doc to up the riba before i start. he is the top hep doc at a university hosp so not sure what his intentions are. maybe he is doing something like what is written below from dr bennet cecil?  

"Ribavirin does not make the intererferon work, but it reduces the chance of relapse after treatment is completed. I start with 600 mg per day in most patients. Patients with genotype 2 or 3 will usually take 800 mg per day after the first month. Patients with other genotypes will usually gradually go up to 1,000 or 1,200 mg per day. If you raise the dose too quickly, the red blood cell count will fall too low causing anemia, fatigue and shortness of breath. If the patient is not responding I usually stop treatment. If you cure the infection, the liver will heal itself."

[Kalio1]

Im 3a and relapsed on 800 a day ( I weighed 185 at the time, Im just shy of 6 foot), so did FLGuy I believe. No way would I let him keep me at 800 riba a day THIS round! First time I was tx naive so I folowed instruction ike a good patient and the Tx failed.

[NYgirl]

I opted to take the mfg recommended dosage because it gave me 200 MORE mgs.  I was only supposed to get 800 on weight based.

I'm glad I did it though for my weight it caused big anemia problems...I made it through and did keep the extra riba on board the whole time.

[Kalio1]

Do you know your BMI?

[amirtracy]

ok flguy. spare the riba spoil the tx? My doc reduced my dosage from 1200mg to 1000mg 6 days ago. my hmg is down to 9.8 and i've got an appointment on the 23rd to discuss referral to a hematologist/procrit options. (no insurance. can get free meds but ouch the dr's visits!) my weight has dropped so the reduction is weight-appropriate. i'm in week 25/48. und @ 12 and 24 from pre-tx VL of 10million. anemia is kicking my a$$ so i was happy to reduce THEN. now, 6 days later, i'm worried i've increased my chance of relapse. am i freakin' for nothing? my GI doesn't seem to as "up" on things as some. his standard response is the first 12 weeks is the most important. did i just mess up my chances of svr? thanks you guys.

[copyman]

Kalio my BMI is 26.1. i was hoping jmjm would give me his opinion on starting a lower dose of riba and working it up to 1200 or more. since i have read that the peg is what does most of the work and riba just compliments and helps from relapsing. it seems that the riba does the worst damage (red count, etc) in the begining and then during tx. so why would taking 800mg to start then working up to 1200-1600 not work? perhaps not to shock your system as much. has there ever been any studies done on doing tx this way? the one doc that i posted the article from treats this way and has had great success. i'm not saying my doc treats this way or i would ever tx this way but i just wanted to ask out of curiosity. thanks in advance

[FlGuy]

Ditto what Kalio said.  About the same at start 185 lbs. Although I'll never know, part of the relapse cuprit was the fixed dose of 800 instead of about 1200 I think.  Better to suffer the anemia and be aggresive (aggressive) with procrit and other rescuse med.  I think it was Ben Franklin who say 'Spare the Riba, spoil the tx'.

[GoofyDad]

Tritto what FLguy says. I'm 3a, started at 170 lbs and 1,200 riba. Paid the price with hgb in the 7's and 8's, but glad to have done it as I wait for my 6 mos post TMA. I was unD from 4 week into tx, through 4 and 12 weeks post. Still slinging chicken bones and goat entrails in the backyard every full moon.

Also, for those getting ready to start, note the short tx protocols for 2's and 3's. They use weight based dosing. There was also a study published no too long ago tht favorably compared higher weight based riba dosing to lower WB riba dosing.

And like Beagle says, always grab a handful of nuts when you take you're riba. (Single gals may find that challenging)

[cajunlady]

I agree with all of the above.  I am 51 geno1b weight at begining of tx. 135, starting vl 5.3 million. I have lost 20 pounds so far.  I was started on 1200mg of riba and .5 on my shot.  From what I understand is that my doctors office hits this hard and fast at the begining.  If they need to reduce for whatever reason they can do so.  But, for the beginning; which is the most important in the tx, they hit hard.  So, far that I know of he and his partners in the office all treat hepc and have a complete success rate. SO FAR!!!!
The high dose made it wicked for me at the beginning; some days wanting to quit more than once.  But, things did settle down alot with the sides and I was lucky enough that my body took the dose with no decrease and my sides are few now.  I still get sx,  but nothing like the beginning.  I am now 33/48 in my shots.
And, am still not on procritt or any other rescue drug for low cbc's.

In my opinion, I was undetectable at 12 weeks, so the high dose must have worked so far. Will never know if I cleared earlier than that, because this was my first pcr.  In my opinion, I think the high dose kicked its butt, big time.

Cajun

Good Luck and do talk to your doctor

To me the high dose and maybe getting anemia is going to be the individual and how their health and body takes the meds.

[copyman]

just a follow-up to my previous post. has anyone ever started out with less riba and worked their way up to a higher dose? it sounds logical to me , to maybe get your body use to it. but as i'm learning nothing is logical with this dragon disese (disease)! i will ask him what his reason is for this low riba. this doc treats & has treated hundreds upon hundreds of hep patients and i know (hope) he must have a reason. i'm 6'0 and not obese at 200lbs. my appointment is in 2 weeks and i will post what he said. i'm sure he will give me 1200 riba if i ask for it.

[bobbyullc]

SOUNDS LOW,...I WAS 140LBS AND DID 1000.

[Kalio1]

Medical Recommendation:  male 6' 185bs.
This recommendation is based on a Body Mass Index (BMI) range of 19-25.



I typed in your stats and they come up with 185 at 6 foot at your BMI. So this calculation says you are 15lbs overweight. I was suprised when I did mine, I wasnt aware I was overweight before!

Not saying you are overweight but the "ideal medical weight" I guess is a bit different, according to that you are a bit over. I am no riba expert but if it was me, I'd talk to the doctor about upping it.
Keep in mind I am a biased second time treating relapser LOL

Hope you are feeling ok today.

[friole]

Those weighing less than 143 lbs (less than 65 kg) received 800 mg

[GrandOak]

To answer your question, Pegasys is a flat 180 for everyone.  Only PegIntron uses weight based dosing for IFN, that I'm aware of at lest.

[Kalio1]

Are you finished with tx? Last shot done, fini? I hope I have it right, I think it was just recently.
Big congrats on that, I hope you feel much better soon. You went over a year on tx as I recall.Please keep us posted and stay in touch as you deal with post tx.

[amirtracy]

Thanks so much. boy, there's no NOT worrying about this is there?
if it's not one thing it's another! i sent you an email if you get a chance...thanks for everything.   tracy

[Pdilly]

So with Flguys earlier post saying to go to 48 weeks if you have geno 2 or 3 and are not und at 4 weeks and you have to watch to make sure you are getting enough riba too.  Gosh I need the info because I start treating in 5 weeks.
Now I am getting nervous  and feel that I need to verify everything with the doctor.

[amirtracy]

I'm dying to take procrit. it feels like literally sometimes. no insurance and next dr. appt is the 23rd. i posted above in this thread trying to get some advice 'cuz my dr. lowered my dosage. maybe you could help w/ my question?

[GrandOak]

Just make sure you doc is aware that unlike the Product Inserts for Ribavirin which suggests cutting dosage, that the standard protocol these days is to augment tx with Procrit if Hgb starts dropping.

My first doc wasn't and I've paid a heavy price because of it.  Fortunately for me that I've not paid the heavy toll of sx's associated directly to the HCV tx that many do, which is primarily why I'm looking at a possible 96 wk tx when all is said and the Draco is done enough to stick a fork in his Wyrm hide.

[cuteus]

you are probably ok with the reduction at wk 25, but your QOL can be significantly enhanced by the Procrit, Just watch out for HIGH hgb, is just as bad as too low.
my riba was lowered to 800 for a few months in mid tx and was one of the reasons I extended tx. But you were undetect at wk 12, unlike me. You should be ok, it has not been too long from dose reduction. Make sure they increase it as soon as your hgb responds.

if anyone knows a "dr" who wants the epo, let me know at moniker plus belleus sent to yahoo.

[cuteus]

SOMEBODY please ask for a Procrit donation!!
my 4 vials expire next yr....

[strator]

I started tx at a body wt of 158 on a 5'5" body. My drs office listed me at 165 as I was weighed dressed and in shoes. I started at 1000mg riba and think the wt drop to 115 with the same dosage may have brought about some of the harder changes in the end. That's just an assumption from me because other factors are always involved with this tx. Many have said they noticed no big difference with sides when they were moved up to heavier doses versus body wt.
Be Well,
Don

[FlGuy]

Just to clarify.  The comments I made were about geno 3 and did not include geno 2.  My own personal view, tempered by what the doc said and my reading over the months, is that geno 3 is more similar to geno 1 than it is to geno 2.

[FlGuy]

Don,

Have you had a post-tx PCR yet? If not, when? And how are you feeling?

[friole]

I am done, did 56 weeks on 1200 riba and the usual inf. (don't have the PCR results back yet, but assuem still clear) I am not far enough away from treatment yet to see any effects.  I had a CBC yesterday - (took last inf 08/4 and last ribas 8/11).  My ANC was .7 and the doc said to continue the Neupogen for a couple of weeks.  My HGB was 11.4 and I only  have one Procrit left.  She said take that tomorrow, and I should be good to go - not to refill the rx.  Will actually skip a week and take next CBC on the 28th.
frijole

[stangshelly]

I am 1a course liver grade 2 moderate, when started tx 3/24/06 i had viral count of 4.4 mill from one test then 6.6 mill from one before starting tx. week 12 had dropped to 150,000..on week 21 now and slightly anemic at 10.7 ? my big 24 week coming up soon. i am 160lbs. 5ft 6in. and was started on 1200 mg riba. i am tolerating sides. rash is a pain and bruising, short of breath at times..but the good news is that since off psychotropic drugs for mood stabilization..day 5 brain fog better and feel good...

[jmjm530]

The term "weight-based" ribavirn dosing is used a couple of ways.
In in it's more simple form, geno 1's are advised to weight-base their riba according to a few different charts. One scheme was 1200 riba/day if you're over 165? lbs and 1000mg/day if you're under. I think the European charts had 800 mg/day of riba thrown in as well.

Later, researchers like Dr. Ira Jacobsen expanded the concept a little as in the Win-R study: http://www.hivandhepatitis.com/2005icr/aasld/docs/111805_a.html

And then there are the more tailored weight-based formulas like the ones Goofy mentioned where you figure your dose based on mg/riba per kilo of body weight. Again, there's usually a range and probably different doctors have different preferences, hopefully tailored to the patient's history.

Forgot your genotype, but if you're a geno 1 and weigh 200lbs, then 800 mg/day seems very low. Without doing any calculations, I would imagine that the correct dosage would be between 1200 - 1400 mg/day.

If you're genotype 2, some studies suggest that there's no difference between weight-based riba dosing and the standard 800 mg/day dose. Still, not sure if those studies broke it down to those in the 200lb range and if it were me, I'd probably ask for a little more, but then again, I'm quite the riba hound :)

Geno 3's, which I know the least about, appears to be a different animal from geno 2's and in fact I read about six months ago that geno 3's almost have a different type of disease than the rest of us. I believe Goofy and others have posted studies or Dr. opinions that geno 3's are now weight-basing the riba.

Hope this helps a little.

-- Jim

[jmjm530]

This article shows a range similar to the one Goofy uses above:
http://www.hivandhepatitis.com/2005icr/aasld/docs/111605_t.html

Translating these formulas into actual dosing, I concur with Dr. Goofy that the appropriate dosing is toward the higher end, i.e. 15.5 mg/kg :)

Again, I believe this is geno 1 dosing but maybe applicable to geno 3's. Not sure what the current thought is with geno 2's these days.

-- Jim

[copyman]

thanks for answering some questions jim. i'm geno 1a, VL 9 million, 49 yrs old, normal ultrasound, all bloodwork normal except high cholestrol, waiting to get the bx.

the one question i really wanted to hear you address was the one about starting at a lower dose (800mg)and working up to 1200-1400mg. why would this not work? to give your body a chance to get use to it. has there been any studies on this? thanks again.

[copyman]

ok what about this scenario. if i was lucky enough to have minimal damage show on the bx would you treat with a high VL like i have or would you wait for better tx? please factor in my geno and age. thanks

[jmjm530]

I don't recommend any geno 1 with less than stage 3 liver damage treat with the current drugs right now.  In fact, to do it all over again -- knowing what I do now -- not even sure I'd treat *today* as a stage 3, but this is probably a minority opinion.

A reasonable approach IMO is to wait one year and do a reality check on the Vertext trials. By that time, we should have a pretty good idea of their SVR data and you can revisit the treat or not to treat decision.

But do keep in mind that I had a particularly difficult time treating and still do post treatment. I still think I'm being objective, but maybe if I had a more positive treatment experience, my advice would be more tempered.

Bottom line -- you're the one making the decision, so it's your decision, not mine, not anyone else's. But you did ask :)  

There are risks in treating now, there are risks with waiting. You just gotta weigh em and figure out what you're the most comfortable with.

All the best whatever you end up deciding. Anyway, first things first, your biopsy results aren't even in yet. Waiting for tests does suck. Wish I knew as much as you did before I started treating.

Take care,

-- Jim

[copyman]

ok thanks jim for my specific questions, and also to the others that responded to my posts.

[EquineLori]

Although my original doc. doubled the recommended Riba for my weight, causing rapid and excruciating anemia (plus other factors I previously discused with this group), I fired him and found another doc.  The woman who recommended him to me was allergic to the Riba and it was discontinued for her totally at week 11.  Like your doc., he also told her that the Riba was most effective in the first 12 weeks.  She was geno 2, continued with PegIntron for a total of 48 weeks and has been UND for some time now.  So many differing opinions for so many different patients is confusing at best.  This group provides phenominal information, choices and support.  Thanks to all, Lori

[amirtracy]

thanks for your post. it's good to hear all the different scenarios. there's just no telling is there? this stupid disease is so unpredicatable. who svr's? who relapses? some people treat for sooo long w/ bad results, others treat for short periods of time and svr. hmmmm. again, thanks for your post and have a great evening.   tracy

[jmjm530]

In fact, my original treating doctor recommended I start at 800mg/day of ribavirin because of a family history of coronary heart disease. I nicely but firmly explained that my stress test was normal and I really wanted to pound the virus to death and not go on a lower dose. The NP then pulled out a chart -- European version -- which suggested that at 165 lbs I could start at 1000mg/day. I then told her that the guidelines I was familiar with put me right on the edge of 1200mg/day and that's where we ended up.

As to "amping" up the riba as you mention, I'm unaware of any studies that looked into this. Most of the studies look at what happens if you amp down, i.e. reduce dose, which can be associated with lower SVR.

I would ask your doctor why he wants you to start with 800mg/day. Maybe you have some cardiac or other issues that concern him. However, everything equal, if I were you, I'd go for 1200mg/day and if your biopsy comes out with significant liver damage I might even get more agressive and ask for 1400mg/day. Of course, the more riba you take, the more potential for sides, therefore the more CBC's you want to take and the responsive you potentially want to be with "rescue" drugs like Procrit. it's a good idea to have the rescue drug conversation with your doctor BEFORE starting treatment. You never know what the protocols are until you ask. Some doctors refuse to use rescue drugs -- reduce dose instead -- and that should be something you should know about in advance.

Speaking of riba, someone posted several months ago they were involved in a study of pre-dosing riba for a couple of weeks prior to their first peg shot. I thought his was a fascinating concept but don't know what the follow-through was.

Lastly, let's hope that "high cholesterol" you have correlates with a better shot of SVR like one study suggests and please let us know when you get the biopsy results back. For me at least, this helps one decide how agressively you want to fight the d*mn virus :)Others of course, may disagree here.

-- Jim