Plaquenil side effect?

I don’t know if anyone can help but I started plaquenil on Friday evening and have taken it at the same time each evening (btw 6pm-7pm). A couple of hours later my heart somersaults for a while and sometimes it feels like my heart is in my throat!! I’ve taken my blood pressure too and noted it drops after taking it. Has anyone else experienced this and if so did it go away eventually?

Thanks in advance.

I never experienced any of that on it. I'd call your doctor and discuss it before you take it again. We all react differently to meds.

Good luck,


I didn’t have that feeling. But it did give me very very vivid dreams/nightmares when I took it at night. I switched to taking it in the morning, and that helped a lot.

I have never had that problem either. I take a pill in the morning and one in the evening. I do know that I HAVE to take them with food or I become extremely sick to my stomach. Other than some intestinal issues which went away after a while, thats the only problem I've had.

I can’t take plaquenil, but not because of that side effect. I was very light headed and dizzy. I would contact your rume and see what they think. I stayed in it for 3 weeks but the effects incressed so I am now on methotrexate.

That same thing happened to me! Just out of the blue my heart would start racing over 130 bpm! I'd just hang onto the bed and pray it went away before I had a heart attack. It took it for 9 days and just couldn't stand it any more. Plaquenil has a long half-life and it took weeks before it finally went back to normal.

I don’t get a racing heart but I do occasionally have PVCs (preventricular contractions) which feels like my heart missed a beat. The next one feels harder than normal. Speak with your pharmacist if you’re taking more than one drug at this time. Sometimes that can make it better or worse.

I haven't had that happen, but it does make me very nauseous if I don't take it with food. I only take one pill a day, because taking two a day affects the muscles in my legs, making them very weak and hard to walk.

Thanks everyone. I’ve seen my GP today who didn’t really know what to say so I’m waiting for a call back from my rheumy. 2 weeks ago I started bisoprolol (beta blocker) and ramipril (ACE Inhibitor). Then on the weekend I started 30mg of prednisolone and 400mg of plaquenil. I think it’s all a bit much for my system. So the plan is to stop the ramipril - I don’t have historically high blood pressure and are taking it for prevention of heart failure but the GP thinks it might be sending my BP too low. We said I could continue with steroid as he didn’t think that was causing it. I’m continuing on the beta blocker as this doesn’t effectively reduce BP, just slows the heart down. I am waiting for consultant to call me about plaquenil but I am not taking it tonight!! It’s totally freaked me out. At least now if it happens tonight I know it’s one of 2 drugs. If it doesn’t happen then I know the 2 drugs I’ve left out are the culprit!! I also take ALL my medication with food or after eating as I firmly believe you should do this anyway - I get very sick otherwise! Thanks for your thoughts. I’ll let you know what the rheumy says! And if I get any ill effects tonight!

Hi, Mstinkerbell, I too take Plaquenil and have not experienced any side effects from it. I would advised that you take all of your meds to your Dr. or Pharm to make sure that some other med is not clashing with the Plaquenil and causing those symtoms.

I saw there is at least one other post mentioning a possible interaction with other meds. I'll add what my pharmacist told me about this. When I asked about even my two BP meds being taken at the same time, she said, "Please don't." Even though technially there isn't an issue between an ARB (Losartan) and a beta blocker (Coreg CR), you never know. She said people on a lot of meds tend to handful a.m./handful p.m. to avoid the hassle, but to take them at least at hour apart. Personally I haven't had any real problems with Plaquenil. I usually start very low dose on any new med though.. as I never know what will happen. I'm hypersensitive to a LOT.

I did want to mention that (as noted above), I'm also on a beta blocker.. and it will lower your BP. It just does so by a different means than an ARB or an ACE inhibitor. They all have a different effect to achieve it. I have left ventricular hypertrophy and a couple of very slight areas of regurg, so I'm stuck with these meds for life in all likelihood. I've been on the two meds for about a year now though, and my ejection fraction showed as normal in my last stress test. Because of that and a neurocardiogenic issue, the cardiologist had me cut the ARB in half. I was a little nervous to do that, but he was right that it was making the orthostatic hypotension worse. I seem ok on the Coreg, but I'm on the lowest dose they make for extended release so... can't cut that anyway. It's a capsule. lol It seems like it's balanced for now. My BP is just low enough throughout the day, and it doesn't crash as bad when I stand up now.

Here is where I give you a little info to mull over.. regarding neurocardiogenic conditions. When this racing heart and dropping BP happens... have you been sitting a while and then stood up? If that's the case, you should look up postural orthostatic tachycardia syndrome. You could also web search "POTS syndrome". You have to add the word syndrome, even though it's included in the acronym.. otherwise you get all kinds of links about marijuana. LOL There is more than one related disorder, but they're all considered neurocardiogenic. My cardiologist opted NOT to do a tilt table test on me because of the stress it causes. I've been living with and managing my condition for many years though, and it's stable. You may want to discuss that with yours either way. It's a rare condition, but seems to manifest often enough in the autoimmune community. You're already on a beta blocker, thankfully.. which is the primary course of action.

While I don't think Plaquenil is likely to affect such a condition, anything is possible. I also don't know whether you tapered up to 400mg Plaquenil, or started lower. Taking 400mg right off the bat is very likely to make you dizzy and cause some distress. If you have something like POTS and you create extra stress, then it could make the condition worse.. or just noticable when it never was before.

Here is a study on reports of hypotension with Plaquenil use. It show statistics, the medical conditions those individuals have, and the other medications they take. It still seems that it's uncommon, but possible, and still also points to an interaction in all probability.

I also take a beta blocker, and it does lower blood pressure. I will say that Prednisone caused palpitations and tachycardia, and after taking it a few different times, caused a cardiac arrhythmia. Maybe talk to your Rheum about that as well.

Good luck,


PLEASE DO NOT ASSUME THIS! Like I said, Plaquenil has a long half life...that means how long it remains in your system and can cause side effects. Sometimes weeks. The only way to determine exactly what it is is to stop that specific medication and wait until all symptoms have disappeared. Like I said, with Plaquenil this could take weeks. Then to add in ONLY that medication. If the symptoms then return, then you know which medication caused the side effect/reaction. Otherwise you might assume that a medication caused a problem when it didn't and you will be losing the possibility of taking a medication that could really help you.

I am never, ever a fan of throwing multiple medications at a person all at once. It's like throwing jello against the wall to see what sticks. Nutsm IMHO.

Mstinkerbell said:

I am waiting for consultant to call me about plaquenil but I am not taking it tonight!! It's totally freaked me out. At least now if it happens tonight I know it's one of 2 drugs. If it doesn't happen then I know the 2 drugs I've left out are the culprit!!

I’m quite clued up on the conditions I have - heart related is non compaction cardiomyopathy. I take a very low does ACE and BETA. The BETA I take can lower BP however, it is unlikely to have an affect in that manner with the low dose I take. I note my pulse has reduced that is all. The ACE on the other hand has lowered the BP (I ringed the changes when introducing the meds). When my BP was low last night I was in danger of tachycardia as a low BP sends signals to the brain for the heart to work harder and therefore your pulse increases - if your BP is low enough then a BETA is not likely to help in this situation (with my low dose). This happened to my father 6 months ago when he went into sepsis. This is the reason I am stopping the ACE (for the time being) so that my BP has a chance to recover and I can find out what’s going on. My GP had never heard of plaquenil reducing BP however, it appears evident to me that this has happened as I get my heart flipping in my chest 2 hours after I take it. I haven’t taken it tonight and I’m fine. Both drugs (ACE & Plaquenil) are still in my system but are not causing ill effects now. My guess is an educated one and one agreed with by my GP - it appears that I am having some (hopefully) short term, short lived side effects of the plaquenil. I am waiting for my rheumy to call me so he can guide me further as he may have seen this before. I have since come across another person who has gone through this issue in another forum so I am confident that plaquenil is causing me problems now. Thanks for all your help and thoughts on this issue.





I too take Plaquenil...have done so for almost a year. Had not noticed any BP changes in the past....but recently my BP has been lower than it used to be on routine BP tests. Quite a bit lower actually...into the "not so good" level. Unfortunately I have never correlated the BP reading with the time I take the Placquenil...but will do so for a period of see if there is a connection. I do get the excessive heartbeat feeling now and again...but again did not connect it to the Plaquenil. I will do so in future just to see. Thanks for the heads up. I'll try to let you know if there does seem to be a connection in a bit. Good luck to you!


Any chance you can take half a pill at a AM and lower the doseage impact...and still get the ultimate benefit of the medication? My doctor told me to do this on meds that gave me a reaction initially...and it does seem to lessen the impact while still getting you the benefits. Later you may be able to go back to the once dose daily and be okay once your system is used to the meds. Check with your dr though...before doing that.

@ Ms.tinkerbell, I never take my Plaquenil at night and it is correct it took along time before I felt any relive from the med but it only took care of my skin problem I still had serious pain in my joints that would make me ball up in pain. The only drug that stopped my joint pain was Methotraxate which in commonly used as a cancer drug without this med im in serious pain.

I dont get that kind of feeling, all I get is a blurring sensation in my eyes sometimes when its close to the time of getting that eye test done. About every 6 months. I always worry about results from the Plaquinil because I only see with my left eye, I am blind in my rite eye since birth.

Oh lupussucks that is horrible. I too worry about my eyes as I my sight isnt the greatest (wore bottle top glasses from birth!). I will ask my rheumy about cutting the pill in half or I might just take it in the morning to see if the day distracts me from the feelings. Karenk, I did find a study online that tested 13,000 people on plaquenil and they found it to cause hypotension in 2%. I found this after lots of searching as it was not listed as a side effect and my GP had never heard of it as a side effect however, he said that common sense would mean it could effect your blood pressure either way if it can directly effect your heart (as stated in the little booklet you get with the drug!). He said I must monitor my BP very closely from now on. Please all forgive me if I am replying in wrong places etc. I haven’t got to grips wi this site yet!