Thanks to our friends at SurvivingAntidepressants.org for this excellent document.
https://www.survivingantidepressants.org/topic/7562-about-reinstating-and-stabilizing-to-reduce-withdrawal-symptoms

Reinstatement is NOT a Safety Net

Don’t suddenly go off a psychiatric drug assuming that reinstatement is a safety net!

This is one of the reasons we advocate gradual tapering to minimize withdrawal symptoms. Once the nervous system is destabilized by withdrawal, all bets are off. Humpty Dumpty the egg has fallen off the wall.

What is reinstatement?

Reinstatement means resuming the drug or its equivalent when withdrawal symptoms appear.

According to what medicine knows about psychiatric drug withdrawal syndrome, reinstatement is the only way to alleviate withdrawal symptoms. All the papers about withdrawal symptoms allude to how symptoms usually resolve after reinstatement. This is considered a hallmark of withdrawal syndrome.

Some papers recommend resuming a partial dose of the drug rather than a full dose. See below for discussion.

The inserts in all the newer antidepressants and many other psychiatric drugs advise reinstatement if withdrawal symptoms appear. This is all medicine knows about how to treat withdrawal.

Unforturnately, we have seen reinstatement does not always work. Tapering carefully to avoid withdrawal symptoms is a much safer approach. Medicine wants to believe withdrawal lasts only a few weeks, but evidence is emerging that’s only the acute phase — post-acute withdrawal syndrome can last many months.

What we have learned about reinstatement

From what we’ve learned from patient experience here and other online support sites:

Reinstatement is best done immediately upon appearance of withdrawal symptoms. The more time that passes, the less likely it is to work.
The length of this window of opportunity is unknown, it varies according to the individual. Sometimes people can reinstate successfully months or years after quitting. Others cannot.
Avoid kindling, start low to see what you need. You can always increase if necessary. We advise to initiate reinstatement at a very low dose; we also advise carefully monitoring the result and adjusting the dose accordingly. Do not start at a high dose, your nervous system may be sensitized by withdrawal and you may react badly to the drug, making your symptoms much worse. This is called kindling — see a fuller explanation below.
Often a very low dose will relieve withdrawal symptoms. We have seen that often reinstating a very low dose of the drug — such as 1mg fluoxetine or 1mg escitalopram — is enough to reduce withdrawal symptoms and allow the nervous system to gradually settle down.
Sometimes it takes a higher dose to address withdrawal symptoms, but going up in dose gradually reduces the risk of kindling from a sudden introduction of a higher dose.
If, for example, you were taking 20mg Paxil and quit rapidly or cold-turkeyed only a few days ago, a reinstatement of 5mg may be enough. After trying the lower dose for a week, you can always increase if you feel you need more. If you’ve been off the drug longer, your nervous system may be sensitized and it may be wiser to try a sample dose, such as 0.5mg-1mg to start, to see how you react.
You may be able to reinstate an equivalent drug. Some drugs are siblings, such as citalopram and escilatopram or venlafaxine and deslavenfaxine. Fluoxetine, which is arguably easier to taper than other SSRIs, is often substituted for SSRIs such as paroxetine or sertraline. (Paroxetine is so difficult to taper, you may prefer to reinstate fluoxetine or citalopram instead.) If you have had a prior adverse reaction to a particular drug, it may be advisable not to try it as a substitute.
Cold turkey is not a shortcut to a lower dose

Additional reasons to reinstate only a low dose

Reinstating at a low dose reduces the risk of severe adverse reactions, such as kindling.

Experiencing withdrawal may have sensitized you to drugs and a larger dose may cause an outsized adverse reaction.
If you had adverse effects while you were taking the drug, a low dose may not trigger the adverse effects but still reduce withdrawal symptoms. Adverse effects tend to be dosage-related: The higher the dose, the worse the reaction.
These drugs are vastly more powerful than they need to be; often reinstatement at half dosage is sufficient and many people do well with a lot less. You want to take the lowest dose EFFECTIVE to reduce withdrawal symptoms.
Your receptors may have adjusted somewhat (upregulated) during the time you were tapering or had withdrawal symptoms and don’t need as much drug to return to their prior homeostasis. See Shapiro, 2018. Subtherapeutic doses of SSRI antidepressants demonstrate considerable serotonin transporter occupancy: implications for tapering SSRIs
You have less to taper when you finally do go off, if you can stabilize on a lower dose.
You can always adjust the dosage upward if you find you need to. After reinstatement, most drugs take about a week to reach full effect. Wait until you see the full effect before you make an increase — and then make only very gradual increases.

How long should you give reinstatement?

Unless you have an immediate bad reaction, observe your symptom pattern for about a week to see if the reinstatement is helping. It takes about that long for your body to fully register the addition of most short half-life neuroactive drugs. If you have an immediate bad reaction, reduce or stop taking the drug.
After reinstatement, stabilizing on the drug varies according to the individual. Relief can be felt immediately, after some weeks, or after some months.
A slight immediate improvement is a good sign, this probably will progress as the drug ramps up to steady-state over a week. Improvement often occurs in The Windows and Waves Pattern of Stabilization
More is not better! Your system has gotten a shock and may react badly to “normal” amounts of drug. Reinstatement may not immediately eliminate all withdrawal symptoms. It takes time to stabilize, you may still experience waves of symptoms, which usually lessen as time goes on. Give your nervous system time to settle down, be patient after you reinstate, do not leap to increase the dosage.
Think in terms of months before you attempt to taper again. Once you feel withdrawal symptoms are reduced after reinstatement, give your nervous system time to stabilize before attempting dosage reduction. Do not attempt to taper again until you feel symptom-free, or at least until your withdrawal symptoms are mild, predicatable, and tolerable.

When to discontinue reinstatement

If, upon reinstatement, you very soon feel significantly worse, most likely you are sensitized to the drug and need to take a smaller dosage or, possibly, none at all. You will need to track your daily symptom pattern to see if it’s the drug causing your symptoms. If so, they generally will be worse shortly after you take the drug.
Sometimes reinstatement does not work. The nervous system has taken such a hard hit from withdrawal, it’s destabilized beyond whatever effect the drug might have had.
You get an adverse reaction from the drug. Look up your drug at drugs.com to identify known adverse reactions. A rash is always a bad sign. Sometimes an adverse reaction can be eliminated by taking a lower dosage. Do not mistake an adverse reaction for your existing withdrawal symptoms!
If you have an immediate severe bad reaction, reduce or stop taking the drug

Reinstate at what dosage?

Sometimes reinstatement not only doesn’t work but makes symptoms worse — this is called kindling. That is why we often suggest very, very low doses — to reduce this risk. Higher doses can go wrong in much bigger ways. A very low dose is a way to explore the option of reinstatement with less risk.

Dosage of reinstatement is always going to be a guess. Here are some factors contributing to the decision:

How long you’ve been off the drug. If you’ve just cold-turkeyed 20mg Celexa a few days ago, you might reinstate closer to your original dosage, such as 10mg. (It may not be necessary to go back to 20mg, standard dosages tend to be overly powerful.) Cold turkey is not a shortcut to a lower dose. Reinstatement might not work at all, and you’re stuck in severe withdrawal.
If your system has been sensitized by going on and off drugs. If you’ve had withdrawal symptoms for weeks, your nervous system might have become hypersensitive from destabilization. For example, if you had been taking 20mg Celexa, you might wish to try reinstating at a lower dosage, such as 0.5mg-1mg. It may seem incredible, but these tiny doses are often sufficient to reduce withdrawal symptoms. You can always increase later.
If you have symptoms of hyper-reactivity or alerting (anxiety, panic, sleeplessness), you may be too sensitive for reinstatement. If you want to try it anyway, you might wish to try reinstating at a very low dosage, such as 0.5m-1mg if you had been taking 20mg Celexa, for example.
How long you’ve been off the drug. If you’ve been off the drug for many months, reinstatement is less likely to work. If you want to try it anyway, you might wish to try reinstating at a very low dosage, such as 0.5mg if you had been taking 20mg Celexa, for example, or other SSRIs with a standard dosage of 20mg.
Other drugs you’re taking. Be very careful adding a drug to other drugs. Use the Drug Interactions Checker before even considering this. (Your symptoms may be due to drug-drug interactions.)

None of the above are hard-and-fast rules. There are reports of people with prolonged post-withdrawal syndrome who did better taking a drug at full dosage 2 years later. If you want to do this, please consult a doctor, we cannot advise you on it, the doctor is going to have to monitor your reaction to the drug.

How about substituting another drug for reinstatement? (Especially for paroxetine)

It is preferable to reinstate the drug that caused the withdrawal symptoms rather than another drug, the same drug is more likely to stop the symptoms.

But In some situations, you may want to substitute another drug. For example, paroxetine (Paxil) stands out as being very difficult to taper. It is so difficult, that if you went off paroxetine and you want to try reinstatement, you might want to utilize a very low dose of another drug, such as fluoxetine or citalopram. Fluoxetine and citalopram are most often used as substitutes; fluoxetine has a long half-life, which may make tapering easier, while citalopram’s half-life is a little longer than the other SSRIs.

Milligram for milligram, escilatopram is several times stronger than its sibling citalopram. If you’ve gone off escitalopram and always felt it was too strong for you, you may wish to reinstate with citalopram instead, or fluoxetine.

We always urge attempting reinstatement of a very low dose initially, such as 1mg-2mg, to limit adverse reactions, in case the new drug doesn’t agree with you. All the SSRIs come in prescription liquid form for easy titration.

About benzo reinstatement

https://www.benzosupport.org/notes_on_reinstatement.htm

Thanks to our friends at SurvivingAntidepressants.org for this excellent document. https://www.survivingantidepressants.org/topic/7562-about-reinstating-and-stabilizing-to-reduce-withdrawal-symptoms

Reinstatement- borrowed