Advice on RLS as a reaction to medication?

[RiversofLondon]

Hello,  I currently have long covid and vestibular neuritis, and have had these conditions for around six months. The vestibular neuritis is causing considerable vertigo symptoms.  

Just over a month ago, my GP gave me Betahistine to try and ease the vertigo. Within a few days of this, I began getting very severe RLS symptoms (throughout the day and night, forcing continual movement - not fun with fatigue and vertigo!) as a side effect. Previous to this, I’ve occasionally had very mild experience of RLS over the years. My mother also gets mild symptoms semi-regularly. 

I quickly stopped taking the Betahistine, but the RSL has not gone away. I’ve been managing this and resulting insomnia with sleeping medication, hot baths, compression socks, tens/massage tools etc. I’ve started taking additional magnesium as well. Apparently my ferritin levels are fine according to a recent blood test. I am rather wary of any further medical treatment as I seem to be reacting very badly to side effects at present.  

I wanted to ask whether anyone has come across any information (or advice!) about RLS occurring as a reaction to medication (particularly in relation to Betahistine or histamine-based medication) and/or in relation to long covid?  

I’d also typically take anti-histamines for hayfever over the summer. I’m currently reluctant to do so, as I’m a little worried it may worsen the RLS. Does anyone have any experience or advice on this front?  

Many thanks in advance for any insights!

[ChrisColumbus]

There are a lot of medications that exacerbate RLS. Note the following taken from

rls-uk.org/medical-treatments

"Anti nausea drugs and sedating anti histamines can block the brains' dopamine receptors, increasing the symptoms of restless legs. Anything containing pseudoephrine or phenylephrine should be avoided."

There is more information in that link (although not about betahistine)

[ChrisColumbus]

Unfortunately few doctors know much about RLS, they are not taught about it, and will say things like "ferritin levels are fine": regrettably what is 'normal' for non RLS sufferers is insufficient for us.

Did you doctor do a blood test in the morning after fasting over night, and at least 48 hours since taking any iron supplements give? And did he give you the actual numbers?

We need ferritin to be over 100, preferably nearer 200, and transferrin saturation to be between 16-50% (men)/16-45% (women). Most sufferers will see an improvement if serum ferritin can be brought over 100.

[SueJohnson]

I agree with ChrisColumbus about your ferritin. Did you take the test as he said? If not your ferritin number will be higher and not the number you want. If you don't know the number ask your doctor for it. If it is not over 100, post here and we can give you some advice. On the Betahistine that is strange. I have not heard of that medicine making RLS worse and it is definitely strange that after you stopped it the symptoms have not gone away. Did you change anything including lifestyle changes and what you eat around that time? What sleeping medicine are you taking? Are you taking any other medicines or OTC supplements? What antihistamines do you take? Many medicines and OTC supplements can make RLS worse. If you are taking any and you list them here, I can tell you if any make RLS symptoms worse and if so may be able to give you a safe substitute.

[ChrisColumbus]

Update: betahistine is an analogue of histamine, so it's said that antihistamines could theoretically make this medicine less effective. Although as you've given it up perhaps this info is superfluous!

[RiversofLondon]

Hello and thank you both very much! ChrisColumbus that's really helpful to know re: beta vs anti-histamine. So one could potentially counteract the other...

I don't take any iron supplements, and I had the blood test in the morning but after breakfast, so I'm guessing not quite the conditions that you advise. I saw the numbers (in the 30s or 40s), but that is so wildly off the levels you are saying, I'm wondering if a different scale was used (not sure where either of you are, but I'm UK based). However, you've prompted me to ask for a print out of the results, so I can report back!

SueJohnson Yes, I thought it was odd too, but the shift was very marked. It's not actually down as a side effect of the medication, but I eventually found that a few clinical studies and peer-reviewed papers have made a link between histamine worsening RLS.

No lifestyle or dietary changes then or since. And, by that point, I'd had long covid and the related stress and lifestyle shifts for about three months. I'd pushed myself rather too hard about five days before, had a bit of a collapse and landed myself in A&E - but I can't think of anything else.

The sleeping medication is Zopiclone (3.75mg - 1-2 tablets per night). I'd originally been taking two, but have recently managed to reduce down to one.

Occasional medication for migraines (Rizatriptan and naproxen), but no other medication. I take a general multi-vit, Omega 3, Vitamin D, and a Magnesium& Zinc.

I'm not currently taking any antihistamines. I'd normally get something that is non-drowsy, but nothing specific.

[ChrisColumbus in reply to RiversofLondon]

Just on the subject of ferritin levels: the quoted 'normal' range is huge - the NHS gives 'Normal Ranges Serum Ferritin 15-300µg/l (men and post menopausal women), 15-200µg/l (pre menopausal women)'. It's just that the bottom end of the Normal Range is too low for RLS sufferers.

Patients with RLS tend to have lower than normal iron stores in some regions of the brain. RLS experts recommend that all RLS patients with serum ferritin concentration of 75 μg/L or less and transferrin saturation below 45% should receive a trial of oral iron therapy to raise ferritin levels.

[SueJohnson in reply to RiversofLondon]

Your medicines and OTC supplements are fine. With your numbers in the 30's or 40's and that is actually high since you took the test after breakfast, you definitely need to bring it up, Take 325 mg of ferrous sulfate or 25 mg of iron bisglycinate with 100 mg of vitamin C or some orange juice since that helps its absorption. Ferrous sulfate is fine for most people, but if you have problems with constipation, iron bisglycinate is better. Take it every day, preferably at night at the same time so it is at least 24 hours apart at least 1 hour before a meal or coffee or tea and at least 2 hours after a meal or coffee or tea since iron is absorbed better on an empty stomach and the tannins in coffee and tea limit absorption. If you live in the US ferrous sulfate is cheaper and for most people does not cause constipation but iron bisglycinate is much less likely to. If you can get it an iron infusion will bring it up faster. Since you take magnesium even in a multivitamin take it at least 2 hours apart since it interferes with the absorption of iron. It takes several months for the iron tablets or iron infusion to slowly raise your ferritin. Ask for a new blood test after 8 weeks if you have an iron infusion or after 3 months if you are taking iron tablets.

[RiversofLondon]

Dear SueJohnson and ChrisColumbus , many thanks for this additional information on the range, recommended levels and best approaches in terms of taking iron. It's immensely appreciated. I've now got my own copy of the blood tests - the ferritin is 38 ug/L (down from the last time is was tested in September, when it was at 48). This has given me a lot more to go back to the GP, and much more confidence in requesting they review it. So, thank you both again.

[Hidden]

Hi River, I just wanted to comment on your situation because it’s one with some unusual characteristics. First, I want to congratulate you on getting your RLS mostly controlled, per your more recent post. Second, even though your RLS seemed to correspond to the Betahistine and to continue even after you discontinued the drug, I'm going to guess your RLS was made worse by the worsening (?) vestibular neuritis and the Betahistine was a red herring? As I explained before, when our bodies are under attack, via an infection for example, serum iron does go down and RLS worsens.

You haven’t mentioned the neuritis in your second post so if it is gone, that could be one of the reasons your RLS is more like it was pre-Covid. What a strange and painful ride you’ve had. It has allowed us all to learn…for whatever that’s worth 🌦️

ncbi.nlm.nih.gov/pmc/articl...