Do allergy meds interfere with dream recall ?

Last Sunday I started taking a 24 hr anti-histamine – specifically, Allegra ™
(active ingredient: fexofenadine hydrochloride ) …

… and I immediately went from recalling 1-3 dreams per night to recalling none at all. I put this down to ordinary variability, but on Monday night I again recalled no dreams at all. Missing out completely for 2 nights in a row hasn’t happened to me since I resumed keeping a dream-journal again last month.

I wouldn’t have bothered asking about this so soon, except that at the same time I also started taking B-vitamin complex at bed-time (a B-50 complex, and I know from previous experience that for me, B75 is “too much” for night-time use – it makes my dreaming very “edgy”, very tense and uncomfortable). So, I’m definitely inclined to blame the anti-histamine.

Does anyone know anything about this ?

I am like 99% sure that any sort of medication can affect your dreaming, or otherwise have a placebo effect.

Some drugs like alcohol can repress REM sleep, and cause REM rebound, a long deep dreamless sleep followed by an hour or two of very light, very vivid active sleep, in which dreams can be so real they are frightening, or ‘edgy’ as you put it.
Maybe your drugs are doing the same thing, and your just not sleeping long enough for the REM sleep to kick in.

I’ve tried cutting back on the anti-histamine (fexofenadine hydrochloride) by breaking the tablets in half. I’ve been doing this for three days now, and the results seem pretty clear.

The first morning I had an impressive REM rebound effect (subjectively determined, of course) with very vivid and colorful dreams, but recall was very fragile.
Even though I knew I had at least 3 dreams, only one was retained well enough to record anything about it.

Then this, 2nd,night also had somewhat more vivid dreaming, but not to the same extent as the previous night. Also, recall was still fragile, and was completely disrupted by morning distractions (neighbourly noise) before I even reached for my pen and journal.

It’s looking like I should only take a 12-hr dose of this stuff if I do it early in the a.m, or if conditions get really bad. This is unusual for me; I generally find that antihistamines don’t last nearly as long as they are supposed to, and the “extra strong” doses stop working after only about 4 hours. I’ll have to find out how much they affect my dreaming and dream recall – I hadn’t made any connection before this.

I think it does. ive been on flonase for the past month and i have not been able to remember ANYTHING. just resently now that it is out of my system can I remember my dreams again.

To me, the question is:

a) does this apply to all anti-histamines, or just most, or just some of them?

b) do all (or most) anti-histamines equally suppress dream-recall or REM/dreaming ?

c) is this problem common to most people taking anti-histamines ?

d) is this an effect that diminishes as the dreamer adjusts to the effect of these chemicals on their neurochemistry?


A little research turned up the following:

So it seems unlikely that anti-histamines would be directly interfereing with REM sleep (though I suppose that there might concievably be some rebound effect). However, the above info makes it quite plausable that anti-histamines might interfere with memory, or at any rate with being awake or aware enough to create and consolidate memories.

can you try taking it in the morning instead of at night?

i take claritin 24 hr in the mornings…

I do take it in the morning!

I have tried to take it as early as possible ever since I realised it might be a problem for my dream recall. If things seem ok by the time I’ve finished breakfast and getting ready in the morning, I’ll try to skip it.

Claritin and Reactin only work about 4 hours for me. If I take enough to get me through the day, I start to get a rushing sound in my ears – not reassuring! The Allegra 12-hr dose actually controls (my) symptoms for 12 hours, but interferes with (my) dream recall much longer than that. So now I take Reactin (Cetirazine Hydrochloride 5 - 10mg) in the evenings, after the Allegra (fexofenadine hydrochloride) wears off. I think it still hurts my dream recall some, but not totally. I haven’t tested Claritin (Loratadine 5 - 10mg) yet.

I even had a couple of LDs this week! Maybe all that green tea I’ve been guzzleing recently (often with mint) has been counterbalancing the sleep-effects of the Allegra/fexofenadine hcl.

(Normally, if I drink this much (too much!) green tea I get way too wired to sleep properly. Yesterday I cut back on the tea, and this am my recall was miniscule again (still better than none). It might just be coincidence and normal variation. I’ll have to experiment with it a little and see how it goes.)

A final follow-up:

Cutting to a half dose of Allegra (fexofenadine) helped somewhat, but as time went on my dream-recall steadily declined (not to mention that my evenings were aggravating as my symptoms would re-appear).

So I tried switching to yet another supposedly 24-hour anti-histamine, Aerius (active ingredient: desloratadine). This one worked out much better; I’ve been using it for almost a week now. It seems to help my allergies better, and my recall is securely back in the 2-4/night range. No actual LDs since the switch, but some close calls, and a couple of FAs as well.