No luck finding an article on dosage either. But,

Anonymous
October 15, 2010 at 4:18 pm

I guess this info from Aetna on “Clinical Policy Bulletin: Parenteral Immunoglobulins” (gosh, don’t let that name throw you) explains how to go about it. In-directly. Let me copy and paste some of the article here.

[I]”…Notes: The following criteria are considered in assessing the medical necessity of IVIG for the indications listed above.

1. Clinical monitoring takes clear precedence over laboratory monitoring. If clinical improvement is evident, then laboratory monitoring solely to guide IVIG therapy is not considered medically necessary.

2. In some situations, IVIG may be used for medically necessary indications listed above for a person that has rapidly progressive disease in which a clinical response could not be effected quickly enough using conventional agents. In these situations, IVIG therapy would be given along with conventional treatment(s) and continued administration of IVIG is not considered medically necessary once conventional therapy takes effect.

3. Once treatment is initiated, there must be adequate documentation of progress. If there is initial improvement, and continued treatment is necessary, then some type of objective quantitative assessment to monitor the progress is required. Any accepted metric assessment may be used for objective monitoring of progress, such as the Inflammatory Neuropathy Cause and Treatment (INCAT) scale*, the Medical Research Council (MRC) scale ** and activities of daily living (ADL) measurements. Changes in these measures should be clearly documented. Subjective or experiential improvement alone is generally insufficient to either continue IVIG or to expect coverage.

4. Previous treatment failures must be documented.

5. The diagnosis of the disorder must be reasonably certain, and based on a thorough history and examination, and appropriate laboratory testing (e.g., electromyography (EMG), spinal fluid tests, serum tests and biopsy findings).

6. There should be, depending on the diagnosis and clinical circumstances, an attempt made to decrease/wean the dosage when improvement has occurred. There should be, when clinically appropriate for the diagnosis, an attempt to stop the IVIG infusion if improvement is sustained with dosage reduction. If improvement does not occur with IVIG, continued infusion may not be considered medically necessary.

* The Inflammatory Neuropathy Cause and Treatment (INCAT) scale is used to access functional disability of both upper and lower extremity components in CIDP. The INCAT scale has upper and lower extremity components, with a maximum of 5 points for the upper extremity (arm disability) and a maximum of 5 points for the lower extremity (leg disability), which add up to a maximum of 10 points (where 0 is normal and 10 is severely incapacitated). The INCAT scores may be used to evaluate the effectiveness and need for IVIG. IVIG may be discontinued when there is a lack of clear clinical improvement (i.e., a decline in INCAT disability score or failure to improve by 1 point at six weeks following the initial infusion or return to baseline at anytime following initial improvement of 1 point).

** The Medical Research Council (MRC) scale is used to grade muscle strength. Scale: 0 = no muscle movement; 1 = flicker of muscle movement; 2 = trace movement but not able to fully overcome gravity; 3 = just able to overcome gravity, but not against resistance; 4 = moves against resistance, but weak; 5 = full strength against resistance….”[/I]

So, to begin the analysis, look at Item #3. Pay particular attention to: “…Any accepted metric assessment may be used for objective monitoring of progress, such as the Inflammatory Neuropathy Cause and Treatment (INCAT) scale*, the Medical Research Council (MRC) scale ** and activities of daily living (ADL) measurements. Changes in these measures should be clearly documented. Subjective or experiential improvement alone is generally insufficient to either continue IVIG or to expect coverage….”

First, they tell how to measure progress, or lack of it, in specific clinical (clinical means in the Doctor’s office) terms.

Specifically, [I]”The INCAT scores may be used to evaluate the effectiveness and need for IVIG. IVIG may be discontinued when there is a lack of clear clinical improvement (i.e., a decline in INCAT disability score or failure to improve by 1 point at six weeks following the initial infusion or return to baseline at anytime following initial improvement of 1 point).”
[/I]

Therefore, in case of the INCAT score, you want to see maintenance of the original score and, certainly, no more than a one point drop when beginning the tapering process. But, even a return to ‘baseline’ would be cause to discontinue the taper.

Second, they tell us “nope, your opinion (subjective) doesn’t count.

Third, Look carefully at #6. Ah ha! ‘You better show progress or we’ll stop the authorization.’

Now, then, how does this become an article on dosage?

Inversely.

By that, I mean, what the UCSD Dr. told me. “OK, you’ve improved on 5 days of IVIG. Now I want you to take several cycles of IVIG 3 days in a row every three weeks.” Here is what he said, verbatim, “I explained that it might be that he (me) needs to have high dose bursts of IVIG less frequently rather than low dose frequently.” (whew)

Continuing, the UCSD Dr. said “Ideally, I would like to taper him completely off IVIG….”

The way to control the dosage for the taper is by trial and error (tailored for each patient, of course) based on the criteria set forth in the Aetna article.

And, that’s what I wanted to say before. Cut the dose or increase the time between doses and measure what happens. By measure, I mean the clinical criteria set forth by INCAT and the MRC.

the article is here: [url]http://www.aetna.com/cpb/medical/data/200_299/0206.html[/url]