Metoprolol Tartrate vs Succinate

Hello all,

Wondering if anyone has experience with both versions of Metoprolol? I have been taking Tartrate ever since I got my mechanical valve placed (50MG in morning and 50MG in evening). 

I had some SVT flare ups over the past months (pretty much all summer) and they upped my night dose to 75MG and it has mostly been calm and steady.

Then on the 25th I had a pretty bad bout of it -- I was just sitting in my chair working on my laptop (heart probably resting around 100bpm) and it shot up to 185bpm for about 15 minutes. I started getting very sweaty, chest pains, shortness of breath and dizziness.

I was able to record it on my Apple Watch and shoot the info over to my cardiac team and my EP is wondering if it would be a better idea to switch me to Metoprolol Succinate and then only use Tartrate "as needed" or when it flares up.

They said it is my call.

I can't seem to find any pros or cons on Google outside of Tartrate can't prevent heart attacks (which I haven't had) and that Succinate can sometimes make heart failure worse (which I don't think I have either?).

As mentioned, it has probably been nearly a month since any sort of SVT episode, so I was feeling pretty confident, but the one on the 25th was definitely the highest I have seen my heart go. 

I reached back out to my team to ask them what they suggest, because they are the experts. But I figured I would reach out to the group to see if anyone has had any experience with both or noticed issues switching between the two.

Take care



Metoprolol Tartrate or Succinate

by Gemita - 2022-10-27 20:14:12

Jer, hello, I haven’t taken Metoprolol but I see succinate is an extended release med whereas tartrate is immediate release.  The latter (Tartrate) will obviously hit the blood stream faster but will disperse more quickly unless it is topped up (taken in further doses throughout the day).  

To keep a regular sustained dose of Tartrate in your body would require discipline on your part and adherence to a regular time schedule when you take two or more doses during the day.  Instead Succinate being extended release may only need to be taken once a day for example, will be slower to hit the blood stream but once it has reached the blood stream, it will be an evenly spread dose of the med over 24 hours so you will not get the sudden surges or falls that you might experience with Tartrate, especially if you were to miss a dose.

With an arrhythmia, we can be very sensitive to either too much or too little of the med in our bloodstream at any one time.  For this reason I would recommend the Succinate too. 

It sounds as though your EP might be suggesting you use Tartrate as a pill in the pocket (on an as needed basis) in case you need an additional booster dose to calm any future SVT episodes when you are particularly symptomatic, but hopefully this won't be necessary with extended release Succinate.  

I hope you are doing okay Jer?

Metoprolol Tartrate Vs. Succinate

by Marybird - 2022-10-27 21:31:00

Hi Jer,  I took metoprolol succinate for many years after it was first prescribed after a prolonged episode of SVT with a heart rate hanging around 200 landed me in the ER. The dose was 100 mg and I took it once a day. It seemed to do a good job controlling the SVT but my episodes of SVT had not been all that frequent to begin with. Some years later, I asked my GP ( I lost the cardiologist who had wanted to manage this and my hypertension as soon as I could, I couldn't see seeing two docs) about stopping the metoprolol, and he refused that, with my history of SVT but he did cut the dosage back to 50 mg/day. But then he added a low dosage of diltiazem ER, for blood pressure, though I think both meds together kept the SVT at bay. I took these meds for a number of years.

Fast forward a few more years, and one early pre-dawn AM I woke up with tachycardia that kept going for a few hours. I waited, took the meds, the tachy continued and I went to the ER. The EKG showed the tachy as A-flutter though it stopped on its own shortly after I got there. The ER doc insisted I be admitted anyway and seen by a cardiologist. The cardiologist I saw took me on as a patient, and he switched the metoprolol succinate ( 50mg) to a twice a day (25 mg) dosage of metoprolol tartrate. His rationale for doing so, as he put it, was that the succinate formulation loses its effectiveness well before the next dose is due, the twice a day formulation of the tartrate form keeps the blood levels up better- don't know if this is necessarily the case but the doc thinks so and I still take the metoprolol tartrate. 

I now take 75 mg twice a day, for a total of 150mg metoprolol tartrate daily. I have long since gotten over any side effects of this med, though I still have some breakthrough tachycardia- it's now mostly A-Fib. I also take diltiazem ER at 360 mg/day ( two extended release capsules, morning and night, and find that this combination- metoprolol and diltiazem seem to do the best job at minimizing my A-Fib/ tachycardia activity. I have 50 mg metoprolol tartrate tabs and take 3 of those a day, ie, cutting one in half so it's 1.5 tabs twice a day. But this dosage could also be taken as 50 mg tabs three times a day. It's whatever works for the person. 

The cardiologist has suggested to me that in the event I'm feeling especially "tachy" or have a prolonged episode I could take an extra 25 or 50 mg metoprolol tartrate to see if that helps. Most of my tachys last less than 30 seconds so I have yet to do this. But I think his suggestion shows there is some flexibility in taking the medication to best control tachycardias in individuals, though you don't want to go overboard on the meds either. 

As for the differences between the succinate vs tartrate forms of metoprolol, my own personal experience has been that the multidose tartrate form works better for me than the single dose succinate. I don't know if this is true for everyone, but I seem to be one of those folks for whom extended release forms of medication does not continue working for the full 24 or even 12 hours. I saw that specifically with a single 180 mg diltiazem ER, at a time when we were trying to see the effects of this drug instead of metoprolol. I think it took about 5 hours for the diltiazem to kick in, the desired effects lasted maybe 8 hours, then it was back to tachycardia city for me. I'd think taking two doses of an extended release drug would give overlapping efficacy, I now take two extended release diltiazem caps a day. And I suppose an option for you might be two lower dose metoprolol succinate tabs, one morning and one evening to see how that goes.

Everybody's different, and as I understand it there is some leeway in the formulation and dosages in heart rate control drugs such as metoprolol, so there is some trial and error in determining what works best for you. I wish you luck in finding your best combination of drugs, dosages and timing. 

I've had both

by AgentX86 - 2022-10-27 22:05:54

The succinate version is the generic name for Lopressor XL or EXtended release. It's just the slow release version of  tartrate. They do the same thing.

I take the succinate twice a day, which is unusual.  I'm really not sure why but I do what my cardiologist says (or I'd find another).


by Gemita - 2022-10-30 05:58:42

By the way, nice to see your pic in the gallery.  Thank you for taking the time to do this.

Hope your SVT episodes have calmed.  Only time will tell what med will work best for you and it will usually come down to a lot of trial and error and we mustn't be afraid to experiment, with doctor's blessing of course.  I am still doing this to see what helps and there is absolutely nothing wrong with that. Over time our heart condition and lives can change, so we need to adjust our meds too sometimes Jer.

An arrhythmia can be difficult to assess.  A lot of it is watching, waiting and learning how our arrhythmias behave or start.  Sometimes there are no obvious triggers.  At other times we have clear triggers.  

Getting tachycardia mainly at night could point to problems during sleep, like worsening heart failure/heart disease, breathing problems associated with lung disease or even sleep disordered breathing associated with sleep apnea, which I see you have. 

Getting tachycardia during the day when exercising for example is quite common among athletes, since exertion may trigger a fast arrhythmia like SVT or short episodes of non sustained VT.

Personally I find that beta blockers are not always helpful since they go on working even when we have no need for them with "intermittent arrhythmias".  A beta blocker usually needs to be taken indefinitely too once a fast arrhythmia has been detected especially if we are symptomatic during episodes.  Ideally I would like to be able to manage with a pill in the pocket only type medication on an as needed basis, although this method of control would not be as effective as taking a daily beta blocker to help prevent a fast arrhythmia starting.  Also a pill in the pocket med would take time to work at a time when you might need immediate help to control your heart rate.  A further discussion with your cardiologist/EP on the best med for you might be a good idea, although I believe Metoprolol is a well tested and safe cardio selective med to take long term Jer

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