Follow-up: Where the four-week escalation interval comes from, and what it is not posts 61–90
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Concentration and dose get conflated constantly in this subcategory. Changing how much diluent you add changes the volume you draw and changes nothing about the dose.
I have separated what I observed from what I concluded, which does not always happen.
Genuine question rather than a rhetorical one: has anyone here actually observed four-week escalation interval, as opposed to read about it? The thread is long and I cannot tell.
Post #61 is the version of this I will quote in future. One addition.
Two people in this thread mean different things by four-week escalation interval and are disagreeing about the definition while believing they are disagreeing about the facts. Worth pausing to define it.
Dose and effect are not linear across the studied range for every compound in this class. Assuming a doubled dose gives a doubled effect is the reasoning error behind most disappointment.
I am aware this is the third time this month I have made this point.
I had written a reply contradicting post #65 and deleted it. Here is what survived.
If someone has run four-week escalation interval properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.
Confirming post #65 from a second method, which matters more than confirming it from a second person.
Nothing here is medical advice, and a titration question is one of the few where a prescriber can genuinely answer in a minute what a thread will take a week to circle.
Everything in post #65 holds. The case it does not cover is the one I have.
The four-week escalation interval is a convention from the pivotal trials, not a pharmacological constant. The pharmacological argument is that with a week-long half-life, four weeks approaches steady state and you can assess the dose fairly. That is an argument for not going faster. It is not an argument against going slower.
Adding the caveat now so it does not have to be extracted later.
Narrowing post #69, because the general version has more than one answer.
My experience of four-week escalation interval contradicts the reply above. I am posting it as a data point rather than as a refutation, because one person's experience is exactly that.
Concentration and dose get conflated constantly in this subcategory. Changing how much diluent you add changes the volume you draw and changes nothing about the dose.
Adding what did not work for me on four-week escalation interval, since the failures never get written up and they are half the useful information.
Building on post #72 rather than restating it.
Titrating on tolerability rather than on the calendar: some people escalate when they tolerate a dose well, others escalate on the prescribed schedule regardless. The published trials used a calendar-based schedule. Tolerability-based escalation has no formal evidence base but is not uncommon in practice.
The conclusion is tentative; the arithmetic underneath it is not.
Post #70 put the caveat in the right place and I want to underline it.
The documentation on four-week escalation interval is better than this thread and I say that as someone who has posted in the thread.
An observation about four-week escalation interval that I cannot explain and am posting anyway, on the principle that unexplained observations are more useful public than private.
Concentration and dose get conflated constantly in this subcategory. Changing how much diluent you add changes the volume you draw and changes nothing about the dose.
Right — I had this wrong and I am glad to have read it before it mattered.
Coming back to post #77, because the follow-up matters more than the original answer.
The four-week step is a trial convention, not a pharmacological constant. It is roughly four half-lives for a week-long half-life, which is the interval at which you are assessing a stable concentration rather than a rising one.
I am confident about the direction and much less about the magnitude.
On post #80 — agreed on the reasoning, with one qualification.
Four-week escalation interval: I would want to see the raw numbers rather than the summary before agreeing. Summaries lose exactly the information that would settle this.
My understanding of four-week escalation interval is a few years old and may have been superseded. If it has been, I would genuinely like to know rather than keep repeating it.
There is no published evidence about slower escalation because nobody studied it. That means the trials support not going faster and are silent on going slower, which is a different claim from "slower is fine".
Post #83 is right about the mechanism and I think understates the practical bit.
Concentration and dose get conflated constantly in this subcategory. Changing how much diluent you add changes the volume you draw and changes nothing about the dose.
I came in to disagree and I am leaving without a disagreement.
Two sentences on four-week escalation interval and then I will stop, because the rest is speculation and the thread is better without mine.
What is documented is narrow. What is inferred from it is broad. The gap between them is where every argument here lives.
I had written a reply contradicting post #83 and deleted it. Here is what survived.
Dose and effect are not linear across the studied range for every compound in this class. Assuming a doubled dose gives a doubled effect is the reasoning error behind most disappointment.
Confirming post #87 from a second method, which matters more than confirming it from a second person.
There is no published evidence about slower escalation because nobody studied it. That means the trials support not going faster and are silent on going slower, which is a different claim from "slower is fine".
The claim is narrower than it sounds, and deliberately so.
Taking post #87 at face value and following it one step further.
What I would check first on four-week escalation interval is whether the thing being measured moved or whether the way of measuring it moved. Those look identical in a graph.