Why taper by 10% of my dosage?

[JohnM]

Hello all,

 

I have seen that in this forum often the terms hyperbolic and exponential are used synonymously or interchanged. However, they are 2 different mathematical functions (see also for example https://simplicable.com/new/exponential-vs-hyperbolic).
Sometimes it is written that a tapering which reduces 10% in a certain period of time would be hyperbolic, in fact it is an exponential tapering and not a hyperbolic one. A hyperbolic tapering uses a different mathematical formula, and in particular is not the same for every drug, moreover it also depends on the drug dose. So the calculation is a bit more complicated than with the exponential method, and there is no generic formula which is applicable for all drugs and dosages, e.g. 10% reduction within a certain time.

[Altostrata]

Hello, @JohnM

 

The staff is aware that hyperbolic and exponential tapering are not the same, though an exponential taper approximates a similar curve. Nowhere do we claim that an exponential 10% taper is a hyperbolic taper.

 

The term "hyperbolic taper" came into use in 2019, with the publication of Horowitz, M. A., & Taylor, D. (2019). Tapering of SSRI treatment to mitigate withdrawal symptoms. The Lancet Psychiatry, 6(6), 538–546. https://doi.org/10.1016/S2215-0366(19)30032-X

 

I know because I was involved in the discussions of the draft of that paper. Peter Gotzsche pointed out the curve was hyperbolic.

 

Now, the hyperbolic taper for antidepressants is also called the Horowitz-Taylor Method. 

 

We do not give people instructions for a hyperbolic taper because we do not have the calculations for each drug. Mark Horowitz is writing a manual containing this information for doctors. However, the 10% exponential taper is good enough, it's relatively easy to implement, and that's what we talk about here.

 

See Why taper by 10% of my dosage?

Why taper? SERT transporter occupancy studies show importance of gradual change in plasma concentration

 

Horowitz , 2019 Tapering of SSRI treatment to mitigate withdrawal symptoms

Discussion of a scientific journal article with data supporting a very gradual taper.

 

[JohnM]

Hi Altostrata,

 

Thanks a lot for your reply. I am glad that you think that the two methods are indeed different.
I myself am very reluctant to speak of an approximation of the two curves, because there are constellations where they are quite different.
And it is indeed the case that in the forum it is claimed that the 10% method is hyperbolic; for example, also in the article you linked (see below). 
I hope to have contributed to more clarity in this matter with my critical remarks and thus to have served the purpose.

"In a nutshell, the 10% taper method recommends a 10% dosage reduction every 4 weeks, with the 10% calculated on the last dosage. The amount of decrease is proportionate to the last dosage (not the original prescription) and keeps getting smaller.  (See graph comparisons at the bottom of this post.) 

(In mathematical terms, this is a logarithmic progression yielding a hyperbolic curve.)

 

A linear reduction of 10% on the original dose results in reductions being a larger and larger proportion of the dosage you're taking currently.  (See graph comparisons at the bottom of this post.)  These larger decreases tend to be destabilizing and cause withdrawal symptoms.
Those finding the 10% hyperbolic reduction method too slow can speed up by making 10% (or less) reductions more often. Making smaller changes more often is less likely to perturb your nervous system than larger changes less often. However, if you get withdrawal symptoms, your nervous system is telling you that you are tapering too fast."

 

 

The following shows a HYPERBOLIC taper of 10% every 4 weeks. 

This shows tapering from 100mg to 0mg, but the curve would be the same for any starting dose.

 

 

 

[Altostrata]

When it comes to psychiatric drug dosing and receptor occupancy rates, the exponential reduction method and hyperbolic reduction method are close enough.

 

Exponential reduction requires no special calculations other than a percentage of the last dose and may be used when specific drug receptor occupancy rate charts are not available.

 

Post #1 corrected, thanks for the pointers.

[Nicolas45140]

https://willhall.net/comingoffmeds/
 

[Lady123]

So I’ve been tapering using the 10% method each month. At 2.1 mL/mg, I started to experience more severe withdrawal symptoms Ie: panic attacks, tremors, dissociation, and dizziness.  I’m on Day 7 of this dosage, should I continue at 2.1 or should I go back up to 2.3, my previous dosage? 

 

In the future when I’m fully stabilized and ready to taper again, what would be a more tolerable percentage to cut to? Do a lot more people have success with 5% or less once we get to the “lower dosages”?