Dosage of PegIntron (FlGuy, anyone)

[zazza]

"PegIntron should be administered as a subcutaneous injection at a dose of 1.5 mcg/kg."

If this is the case, why is the dose for 66-75 kg 100 mcg PegIntron?

66x1.5 = 99 mcg
75x1.5 = 112.5 mcg

I have gained 15 lbs while on tx, and my weight is now 75 kg (165 lbs). My doc won't let me increase the PegIntron, since the limit for 120 mcg is 76 kg.

Also the dosage of Rebetol is different from Copegus. At 76 kg you get 1200 mg Copegus, but only 1000 mg Rebetol. Why? Does not the lower dosage of PegIntron and Rebetol compared to the dosage of Pegasys (180 mcg for all) and Copegus reduce one's chances of SVR?

[jmjm530]

You may find slightly different weight-based guidelines, but 1200 mg of Copegus is the same amount of riba as 1200 mg of Rebetol. Riba dosing has evolved some recently and many docs take other factors into account -- besides weight -- such as hgb drop, overall tx tolerance, and viral response. While I'm not aware of any studies (other than some extrapolation of the Sweedish Pilot study and related research) that detail the benefits of upping riba later in treament -- but since you are a slow responder, I personally would push for more riba, depending on the factors mentioned, esp if your hgb hasn't dropped significantly. That said, your 1000mg/day dose appears to be within the standard guidelines I'm familiar with, even given your weight gain.

-- Jim

[jmjm530]

As  a Pegasys guy, don't know all that much about Peg Intron, but I imagine the same principle applies. If you're a slow responder, handling sfx OK -- and esp if you have significant liver damage -- then I suppose a very good argument could be made to increase the amount Peg Intron if your weight-gain puts you into the next category. Pegasys was developed as one dose (180) for all, but some docs (including my original hepatologist) suggest that Pegasys is therefore better for lighter folks (they get more of the drug) and Peg Intron better for heavy folks (they get their Peg Intron adjusted to weight).

-- Jim

[PSP-n-Me]

I gained 7 pounds since I started treatment and the Clinic I go said it would be of no benefit to increase the Riba after UD status is acheived

[FlGuy]

Sounds like you doc prescribes 'by the book'.  With the redipen delivery system (amont of peg in the various color-coded pens and the amout you 'dial-in') allows docs to prescribe in those fairly narrow ranges. My doc is fairly aggressive and in the same situation would 'up' the peg, but docs have different views.  Rebetol, copegus and ribavirin are the same stuff and I've seen the ranges for riba, generally, as 13 to 15 mg per kg.  Looks like your doc uses an amount at the lower thresholds.  Only half joking, mabe gain another kg.  As Jim says, doc could use various factors to 'personalize' tx a little more especially for those who demonstrate 'hard to treat' characteristics.

[CockSparrow]

I would wear heavier clothing at the next weigh in. Lead soled shoes should work.
I am not really joking here either. Well i was with the lead.
Entered my head during Tx even though I wasnt on WBR.
The Roche/Schering weight based differences got me too. You would think the riba would be the same for both ay.
CS

[zazza]

My doc sure is prescribing by the book, he looked the dosage up while I was sitting there!

[jmjm530]

I should mail you my doctor's nurse assistant. I just tell her how much I weigh and she puts it in the chart. But in all seriousness, I did load up my pockets with coins etc -- and intentionally wore my heaviest boots -- very early in treatment they actually weighed me then) when I was afraid they would reduce my ribavirin. I would def get that PegIntron issue straightened out and make sure you are getting the correct dose for your weight or a very reasonable explanation from your doctor. Not to suggest anything tawdry, but isn't the Peg Intron dose patient administered by turning a dial or something?

-- Jim

[zazza]

I did wear jeans and boots at the last weigh in. Doc was very observant. I weighed 76.4 kg but he noted that was because of my clothing!

Anybody understand why one would get 100 mcg PegIntron at 75 kg? This would equal 1.33 mcg/kg, not the stated 1.5 mcg/kg.

My hemoglobin has dropped from 15.2 at baseline to 10.1 today. It usually hovers between 10 and 11. No rescue drugs are allowed in my country. My doc says he looks long term since he thinks I am doing fine today, and he wants to be sure I can do my 72 weeks. He refuses to discuss the riba, but gaining a kilo would probably make him prescribe more PegIntron!

Thanks all for answering so fast.

[zazza]

Unfortunately in my country PegIntron comes both as 100 mcg and 120 mcg. I get the 100 mcg redipens. Please send me your doctor's nurse assistant - she sounds wonderful! I am going to the next weigh in in 3 weeks, this time I got an appointment in the afternoon, not in the morning, maybe that will do it. One usually weighs more in the afternoon. Never thought I would want to weigh more.:)

[l-horn]

The guideline for max dose of Intron is anyone over 180 lbs. So, someone who weighs 181 lbs and someone who weighs 381 pounds gets the same dose.

[FlGuy]

I've mentioned this before.  Just before 1st tx I was with the tx doc to decide to begin the adventure.  He pulled out this laminated whee, about the size of a small plate, and stared spinning the wheels and lining stuff up in windows.  The 'guide' was covered with Schering logos.  He said ' genotype 3, 187 pounds...ok here it is....' And, then I was prescribed.  Not exactly 'personalized', because it included no other potential 'adverse' factors or consideration.  And that's how some docs work, how insurance companies require, or government plans deliver.