My rheum suggested Plaquenil for the fatigue.
Can it affect the SFN and POTS ? can it make it worse ?

Plaquenil has been reported to cause nerve damage.

Here is one example from New Zealand;
Risks of Hydroxychloroquine

If you Google further you will find more I think.

Plaquenil has a quinolone central nucleus making it a cousin of the fluoroquinolone antibiotics, which cause PN in some patients.

Thanks!
I will read the link that you sent.
I tried to do too much this week and I'm too exhausted and brain fogged to read it thoroughly right now.

Plaquenil is well known to help fatigue associated with autoimmune disease.

Although I have never heard of neuropathy caused by its use, the article does say there was two reported cases in New Zealand. However, there are thousands that take it, so the risk must be very low.

That being said, it is imperative to have regular (every 6-12 months) checks by an ophthalmologist for toxicity associated with retinal damage (which can be permanent if not caught early). I have taken Plaquenil for 8 years now and still go every 6 months for eye exams and use a chart every WEEK to check for any signs of vision changes.

As ll medications, you have to weigh the risks vs the benefits.

Thanks MrsD and en_block!
I will take into consideration those risks.
en_block, can you do the weekly test yourself at home ?

I'm getting Rituximab and it is helping a lot, the problem is that I can take it only in 6 months interval, while its effect lasting only 2-3 months, so this year has been a roller coaster...
The neuro said the effect is cumulative, so gradually it might get longer.
The rheum suggested the plaquenil to help the fatigue in the meantime, so I'm considering giving it a chance. It is challenging (impossible?) to return to work when 6-8months a year it is difficult to get out of bed and my brain is on a strike.

My SFN and POTS are probably caused by autoimmune disease, if plaquenil is considered a disease modifier drug, can it help with the SFN, POTS?

If you decide to try Plaquenil, check out the list of drugs to avoid that are listed here:

Common Side Effects of Plaquenil (Hydroxychloroquine) Drug Center - RxList

It is interesting to note, that the brand name has been discontinued this year, and only generic is available now.

Drug companies often discontinue their brand name, or sell it when sales are low, and/or they have too many liability suits for damages to settle. When a drug causes damages to people, the liability falls to the patent holder and it is common for the patent holder to discontinue that drug when it can no longer make $$ from it.

Plaquenil has many serious side effects, which are listed on that page as well. So be very careful and monitor yourself for any of these side effects.

Thanks mrsD, I appreciate your help!
I googled about the risks but didn't know about the brand name discontinuation and the possible reasons for this.

This is a tough decision, and to add to these risks, when I tried it 15 years ago I had to stop after 2 weeks because of an allergy reaction. My rheum now suggested that I undergo desensitization to Plaquenil.
This rheum and another one that I consulted with told me that it is considered as a relative safe drug. But when reading online it doesn't seems so.

On the other hand, it has been almost a year since I took a sick leave. The rituximab is helping but for too short duration, and I have to find a way to return to work.

As far as I understand the major risks are when taking plaquenil for many years?
My neuro said the effect of the rituximab might increase and it is possible that within 1-2 years the effect might be more stable. So maybe the plaquenil could help me till then.

The treatments that are offered at a rheumatologist are all very
serious. Compared to them, the Plaquenil is the least toxic.

But compared to OTHER drugs the medical arena has (except for chemo drugs) for many other conditions, it is quite toxic.

So the rheumies would try their least toxic regimen first, and that would be Plaquenil.

So it becomes a matter of degree, and understanding that rheumatology is rather unique. Plaquenil also has some disease modifying potential whereas a symptom relieving drug like gabapentin, does not. Doctors are used to "managing" treatments but some are better than others. Also not all patients are perceptive enough to communicate with doctors (my husband is one of this type) and so a serious side effect may be missed by a this kind of patient.

Thanks
Oddly I tolerated well the aggressive chemotherapy for Lymphoma, which included high dosage of prednisone and I didn't have any problem to get rid of it later.

But I get tons of allergies, side effects and complications from the simpler things such as the skin biopsy, the glue of the electrodes in a sleep lab, and can't even tolerate the large amount of salt required for POTS.

I don't know whether the Plaquenil worth the risks, will have to think about it, and discuss it with my neuro when I will be there next month. I preferred to read about it and to ask here before discussing it with him.

Maybe your husband counts on your knowledge ?

If I didn't questioned, checked and rechecked every doctors' recommendations I wouldn't be alive today...
Not to mention the amount of efforts and time (years) it took me to find a doctor who took the autoimmune options seriously, diagnosed the SFN and let me get a real immunological treatment that finally makes a difference and gives me hope.

Last year a rheumi told me I've got two problems, the first is that I know too much, and the second is my medical problem. Later she said that I need to take X and that she doesn't want to hear what I've to say about it.
Well.... this was the last time I went to her...
I found a much better rheum knowledgeable and emphatic..

I use a chart to check for any signs of vision changes...yes, this is done at home.

As MrsD has said, Plaquenil is one of the least toxic for rheumatologic drugs...but as with any drug, it comes with side-effects. I, personally, have experienced no side-effects from it...and know many others who have not. But of course, there are those that cannot take it due to GI upset (most common) or other reasons. There is no such thing as a risk-free treatment...especially when it comes to treating rheumatological conditions. You just have to weigh the pros/cons and risks vs benefits.

You are doing the right thing...gathering information to make an informed decision. The decision you make can always change. You can stop taking it if you have any negative side-effects (without permanent harm), or if you choose not to take it now, you can decide to try it down the road.