Benadryl - Diphenhydramine hydrochloride

Hi All,

Last night after another really tough day of full blown symptoms I decided to try Benadryl. Not available in Australia in a pure form that I know of, I tried it last year here and had a good result on it one time but an average time for some reason a second time. I can’t remember what happened the second time but it couldn’t have been that bad otherwise I’d remember. I was probably too groggy on it during a dosing during the day. So I took a half tab last night as a sleep aid and it’s supposed to help with migraine for some. I just woke up out of my mind in a really scary way. I slept 4 hours straight which is a record but I woke with my mind having rapid flashing pictures going through it and a sense of almost terror. I’m up now and trying to calm down but feel very screwed up in the head pretty bad. I can barely keep my eyes on this MacBook screen. I hope like hell this is just the Benadryl doing me in and not some new MAV state that’s planning on sticking around. I did have a slightly “hyped” feeling about 45 min after taking it and I just read that it can cause a paradoxical hyper effect in some kids (not experienced by me last year though).

Have any of you tried this stuff and was it a bad effect? These symptoms are seriously nasty and worrying with my brothers arriving Saturday. Despite feeling better yesterday morning following some valium at 4 AM, the rest of the day was very bad while hanging out with my father. Disorientation all day and a squeezing migraine pain in my head with a stuffed cotton wool feeling all day and night.

Never ends it seems. :frowning:

Oh boy, just checked potential drug interactions with Paxil and it looks like Benadryl can cause a “major” reaction. Never thought an antihistamine like this would be a problem with an SSRI but not so apparently.

Lisa – are you aware of an interaction at all? Would explain this new level of craziness I’m experiencing right now. Good job I cracked the pill in half and didn’t take the full 25 mg.

Edit: this is not some easy-going drug. It’s effect on serotonin was the basis for the development of SSRIs. I might as well have shot myself in the foot taking this stuff:

Scott :shock:

Scott, I was looking up this ingredient just yesterday. I read the same Wiki article you cite. I wrote on another thread about it being said that taking children’s benadryl can help migraine /vertigo. I wondered why not the adult stuff and queried if it was merely a question of strength but maybe it was to do with ingredients. Benadryl containing diphenhydramine hydrochloride is not available here in the UK, citrazine is used instead. All I know is that both my brain and my gut reaction tells me not to go near this stuff. I just know it would mess mercilessly with my head. I had no idea about the serotonin connection though nor about any possible interreaction with other drugs. Just shows how careful and vigilant we need to be.

You’re certainly having more than your fair share at the moment! Hope there’s an end to the all the bad stuff soon.


Hi Scott,

Wow, sorry to hear about that horrid experience. I just wanted to jump in and say that I stay away from it because it is supposed to make one drowsy, but with me it makes me hyper and panicky!!! I don’t take sudafed or anything like that for that very reason!!! I never knew about the SSRI?benedryl bad reaction…you would think there would be more warnings about not mixing the two!!!

Thinking of you,

Hey Scott,

Just reading your entries now and am getting the full picture of your horror post our earlier text session. F*ck. That is truly horrorshow.

It is really freaky how we migraineurs can have such severe reactions to such seemingly benign stuff - and all of us have our different demons. During last year’s MAV-crash-fest (then not diagnosed) I was told to try Kwells - a motion sickness drug. You can buy this stuff over the counter in Australia, and they recommend taking up to four pills. I took one, and within 20 minutes could literally not walk and felt like I’d been shot up with heroin or something. I crawled to bed and texted a friend complete gibberish along the lines that I couldn’t come over as planned as I was absolutely WASTED. And not in a good way.

Anyway I’m so sorry you’re wrecked, especially with the brothers coming over tomorrow. Suckage factor just continues to rise for you :x . Is it possible to just take to your bed for a few hours?

I really hope you get some relief soon

Hey Scott,
Oh boy… you are getting the works on this holiday. I am so sorry this is happening and I do hope by tomorrow you will be in better shape. With regards to your question, the only interaction I am aware of is that both drugs have the potential to depress the function of the central nervous system (CNS). Such effects may include ataxia, confusion, drowsiness, respiratory depression, and weakness. These are rare but with our migraine brains I suppose anything is possible even with teeny doese. You know what I am about to say here… go for the sure bet… another hit of valium instead. The half life of benadryl is maximum of 10 hours (usually out of your system in 2 hours) so by Saturday it should be well out of your system.

Keep us posted. Hang in…


It is so interesting that you wrote this, as I NEVER take benadryl, but took one pill wed night, as my allergies have been out of control and claritin hasn’t been helping. Despite all the sedation, etc., associated with MAV, I have to say that my mind is still sharp; I am never confused. When I woke up Thursday morning, besides being extra sedated, I was confused until about noon. It was the weirdest thing - I was thinking about how far along I am with the pregnancy and was just perplexed about how I could possibly be 17 weeks, and couldn’t figure it out. It was very strange, but I got better in the afternoon. II NEVER had an experience like that before. hope you’ll get better as day progresses.
I am not a physician, but you are on a very low dose of your medication and didn’t take too much benadryl. I would certainly not worry about any dangerous interaction or anything like that.

Thanks all for the input on this. I really appreciate it. Man, what would we do without this forum!? I just woke and the crazy symptoms have dropped off a fair bit but are still there … it’s like the 12:15 AM train took me out. The good news out of all of this disaster is that I got 8 hours of sleep for the first time since leaving Sydney last week in two 4-hour chunks. That alone has to pay off today. The rapid fire imagery in my head was totally bizarre last night. The effects should mostly go I hope given the half-life has passed me by now.

Interesting that some of you were also looking into Benadryl this past week and that you felt so weirded out Lisa the next morning after using it. There was a woman who was a regular on the Healthboards years back who swore by Benadryl – that it killed her symptoms and gave her a break. Of course she was on no other drug so maybe, like most migraine meds, it was OK for her but was disastrous for others.

There was an interesting opening paragraph in the the NY Times the other day ( … ef=science):

— Begin quote from ____

“Chronic patients — those who are laid low 15 or more days a month — often cycle through drug after drug in search of relief. They also contend with side effects like mental sluggishness and stomach upset. Treatment involves guesswork because doctors have not pinpointed what causes migraines, nor do they know which drugs will best help which patients … it can be a merry-go-round going from medication to medication in pursuit of control.”

— End quote

That is one of the most accurate things I’ve read in a newspaper article about migraine in a very long time. George, print it off and show your parents that opening para.


Hi Scott - I work with older adults. In geriatrics, Benadryl is known to be a major problem; I’d say that in many ways, migraineurs and older adults are similar in that we are like canaries in the coal mine - we react to things that perhaps the general population can tolerate, but that doesn’t mean there isn’t danger there:

In a discussion of treatment of insomnia for the elderly

"Although diphenhydramine [Benadryl] has sedative effects, it also has strong anticholinergic effects and should be avoided in the elderly for the treatment of insomnia.

Diphenhydramine can cause blurred vision, urinary retention, confusion, hallucinations, dry mouth, constipation, and is associated with delirium in hospitalized elderly patients.

Many of these complicate and prolong hospital stays, and can begin a ‘vicious cycle’ or ‘domino effect’ of adverse events."


Thanks Maryalice – definitely won’t be going there again. Agree that a migraineur is likely just as wide open for nasty side effects as an older patient. What a pain though. S

I’m really crashing badly here. It’s got to the point now where I cannot sleep at all because any position I lie in causes positional vertigo which in turn triggers a heavy physiological anxiety response combined with even more vertigo. Lying on my left side is very bad, lying on the right is impossible, and now lying with head propped up and straight ahead is still causing heart palps with eyes shut. Totally bizarre but this is what MAV does to me when I fall this far down the hole. I’ve taken 5 mg of valium now and it’s barely taking the edge off of this effect which has been my complete undoing in the past without being drugged up on Cipramil.

Lisa – do you think I should crank up the valium higer to see if I can combat this? It’s doesn’t seem to be hugely effective right now, at least not at 5 mg which has always been the highest dose I’d use in a given day. I wonder if I can weather this hurricane by doing so and coming out the other side? I’ve never been this rough and done so before without resorting to Cipramil (and I HATE that stuff). I’ve got to salvage this holiday somehow. Supposed to fly to Winnipeg next Friday and I can barely walk to the bathroom right now without feeling like I’ll fall over. Just unreal.

Scott :frowning:

Scott, your experiences this trip are just unbelievable, seemingly never ending. I recognise the inability to lay down on either side without vertigo, and also the lying with head propped up and all to no avail. At times like that I’ve had to sleep sitting up in bed with cushions behind me. Sometimes being so out of control led to inevitable anxiety and a racing heart and then I had a right cocktail going on! Not pleasant at all. I wasn’t on meds so just had to sit it out but fortunately I had the luxury of time to be able to do that. I didn’t work, my kids were older and I wasn’t on holiday as you are with commitments to see people and having to travel. That would have added to my anxiety enormously and I think you’re extremely courageous to be doing what you’re doing.

I know very little about meds so can’t help there but hopefully Lisa might be able to answer your query about valium. I hope you find a definitive answer to get you out of trouble. Best wishes.


Hey Scott,
You poor thing! I am so sorry you are getting hammered. Regarding the valium I would take 2.5 mg every 4 hours 4x/day to start. Total of 10 mg a day. This is still a VERY low dose, I promise. I would try to knock this out and it is a great time now for a trial as you are so desperate. The nice thing about valium and the benzos is that you don’t have to wait 3 months for them to work. With valium, you should know in about a week (I suspect for you in a day or two) if this is a maintenance dose for you. Once again, 10 mg of valium a day is still very low, don’t worry, and it will give you even more evidence for your doc back home that benzos could give you your life back. It is also very easy to switch over to clonazepam if that is a more desirable drug for you when you return to your doc.
Stay in touch with us Scott. I really hope you find relief.


I am so sorry to hear all this. Please continue to let us know how you’re doing. I’ll be thinking of you.


Oh, Scott. I am so sorry you are having so many symptoms, day and night, during your vacation. I am sure you looked forward to this time and yet your health has just been rotten. I am so thankful that you have been able to get some advice from Lisa. I hope today is a better day for you.

Good luck,

We are all thinking about you and hoping you are better. Please keep us updated and know our thoughts are with you.

Sounds terrible man. I would bump up the valium as Cipramil doesnt seem to ve an option. Have you tried Klonopin? Tried ut the other day and just made me drowsy but might be worth a go? Hope things improve.

Oh wow! You’re in my prayers for a quick turn-around.


Thanks all so much for your kind words. Really helps to know you guys are out there.

Today it feels like I’m walking along the edge of a cliff and the wind is constantly trying to blow me off. Lisa, I’m following your advice and am going to try and defeat this episode with valium alone this time. The tough part now is the massive serotonin drop that must have occurred over the last few nights from the extreme night anxiety induced by the positional vertigo. I feel ultra shell-shocked and a bit black today and finding it really hard to even want to engage with anyone … have definitely dropped down more than a few notches on the ladder. I want to crawl under a rock … most of the time I feel like I’m faking it talking to everyone pretending that I’m not feeling so shocking. Anyway, this has usually been the time when I capitulate and end up on an SSRI. I’d really like to see if I can get through this without that happening. Again no precedent for this although I’ve never used valium at the dose you suggested during such an event. I just need to get through ONE night without the vertigo and resultant anxiety to gain some ground and a foothold. I’ll do 2.5 mg after dinner and another before bed and hope that will do the job.

Apart from the above, being in Toronto is good and the weather is great. We’re all planning to head down and see the annual air show over the lake tomorrow.

Scott :shock:

Hope you find some relief tonight Scott. Perhaps the Valium will help you get some much needed sleep.

As a little girl, I remember when my grandfather and father took me to the Air Show and Canadian National Exhibition in Toronto. Enjoy your day.