Pregabalin long-term side effects

[PrairieNorth]

I was diagnosed with RLS about a year ago, and I was prescribed pregabalin. Initially I took 75 mg per day at bedtime and later that was boosted to 100 mg at bedtime. It was very helpful at first to reduce the tingling in my feet, face, and arms that arose at night. That didn't help much in the daytime, though, where the tingling recurred through each morning and early afternoon. After I had used pregabalin for about 5 months, I also began to experience "wooziness" in the morning soon after I awoke. It became increasingly severe as the months passed, often lasting into the afternoon. It was like a brain fog, making me feel groggy and dazed.

I was told that side-effects of pregabalin typically arise early on during treatment, but not months after starting. But after a variety of tests, no other cause could be detected for those symptoms. So, I decided to gradually reduce my pregabalin dose over several weeks. It wasn't easy because at each step down of 25 mg I felt worse for several days, but then recovered. Finally, a week after I had quit completely, the morning wooziness had stopped. It's been 11 weeks since then, and although my RLS tingling symptoms reverted, in my case that's more tolerable than the wooziness.

It would be very useful to know if this happens to other people too, or if I am the only one. So if any of you, who are reading this post, have experienced gradually worsening side-effects with pregabalin, please leave a comment.

[ViewsAskew]

I have not had that issue with pregabalin, but have with other medicines - where side effects get worse later on and the doctors say it cannot happen. Well, it can!

Frustrating for you, I would guess!

For you, do your RLS/WED symptoms get better if you walk around or are busy?

[PrairieNorth]

With my RLS I have the tingling sensation, but no involuntary movement or urge to move my legs. However, if I do move, such as to get up to walk to the bathroom in the night, the symptoms reduce for a while. That also makes me fully awake, so its the movement or alertness or both that relieve it. I understand that's typical of RLS. There seems to be a limit to that, however. If I go for a hike during the morning, strong symptoms arise in my feet. By evening I generally feel OK, and then the cycle starts again overnight.

[ViewsAskew]

Some of us find that we have RLS/WED as well as something else that feels similar. For example, one person here had RLS/WED, but she also had a small fiber neuropathy and they seemed similar enough that she couldn't distinguish.

I wonder if that could be happening with you? It is SO hard to describe our symptoms, which makes it so difficult for doctors (and us) to determine when we all might use slightly different words.

Have you had your serum ferritin as well as other bloodwork done?

[PrairieNorth]

On the matter of the RLS diagnosis, I have had bloodwork done, including ferritin, Vitamin B12, HbA1c, etc., which were in the normal range. I had a nerve conduction test done on my arm and leg, result normal. I have had ultrasound tests on circulation, result normal. I had an MRI of my brain and spine looking for demyelination, but none was found. There is no test for RLS itself, so lacking any detectable cause, RLS becomes the diagnosis by default. Pregabalin did help, but it helps for other conditions too, so maybe there is some confounding factor here. In any case, I couldn't tolerate the pregabalin any longer, and I wonder why that might happen.

[Polar Bear]

You say your ferritin falls within the normal range which can be anything from 20+. However those of us with RLS do better if our ferritin is up around 75. Even better at about 100. You should check what the exact number is for your ferritin and if necessary work on raising this.

[ViewsAskew]

To add to what Betty said, I actually need my ferritin over 200, and preferably over 300, to get any additional iron into my brain, which then helps reduce symptoms. That is beyond what is considered "normal" for people, however.

[PrairieNorth]

Thank you for the advice about ferritin. My last ferritin level was 152, about midway in the normal range of 30 to 300. So it looks like more iron won't help in my case.

RLS is still called a "syndrome," which means that the cause is not well understood. It seems that there are a variety of known causes (iron deficiency, vitamin B-12 deficiency), and some cases that just remain mysterious. They all get lumped under the umbrella of "RLS," and probably some idiopathic neuropathies get diagnosed that way too, when the symptoms are similar.

One advantage of pregabalin is that it reduces symptoms from a variety of causes. That's handy, but it's also a risk. Maybe in some of those cases it's not the best choice of treatment. If there are side effects that arise over time for some patients, that could be a clue.

[Rustsmith]

Although the RLS name indicates that it is a syndrome, that is a holdover from decades ago. About 15 years ago, there was an attempt by many international RLS organizations to change the name to Willis-Ekbom Disease because the experts recognized that is is not a syndrome but a disease because they understand a great deal of the processes involved with the causes of RLS. This would have properly classed the condition as a disease as well as it would have honored the two doctors who are credited with it discovery.

RLS researchers understand why it hits pregnant women, kidney patients, severely anemic individuals, Parkinsons patients and even those of us with ideopathic RLS. They understand the specifics of how low iron in the brain triggers a chain reaction within the neurotransmitter/receptor network in the substantia nigra portion of the brain that is responsible for controlling movement and sleep. This understanding explains why the various accepted treatments work and others do not. They therefore agreed that RLS is a disease and not a syndrome.

Organizations around the world tried to change the name from RLS to WED, but the RLS name was too well entrenched in the minds of clinicians and some researchers. After a few years of fighting to change the name, the international RLS organizations finally voted to give up, much to the extreme disgust of many severe RLS patients (including the moderators of this board).

However, the cause of low brain iron that results in RLS varies from individual to individual. The root disease mechanism stands and so most of the basic research being done today is looking to define factors such as the details of the very complex iron transport mechanism across the blood brain barrier for those of us with high ferritin (mine is over 450 with no benefit) as well as why others seem to require higher ferritin levels than others to maintain control. The research is also looking at how opioid meds are able to bypass the effects of low iron upon the adenosine/dopamine/glutamate neurotransmitter/receptor system that results in our movement and sleep problems.

[Wilson09]

Thank you for sharing your experience, PrairieNorth. Your description of the delayed onset and worsening of “wooziness” or brain fog with pregabalin resonates with some reports in the literature, although such side effects are often noted early in treatment rather than months later. Pregabalin is generally considered effective and relatively safe for RLS, but dizziness, somnolence, and cognitive effects like confusion or brain fog are documented side effects that can persist or appear during long-term use. Your gradual tapering approach was wise, as withdrawal symptoms can occur. It’s important for others experiencing similar symptoms to discuss them with their doctor and consider dose adjustments or alternative treatments. Sharing your story helps raise awareness that pregabalin side effects can vary over time and underscores the need for personalized management.