but I didn't realize there was that much of a spike in the release of the Tartrate version.
as it happens tartrate works really well for me, you'll notice that the graph only shows
one administration of the 50mg of tartrate.
so taking two administrations would simply add the first bit directly after that.
Also since you can see the effect is so much more pronounced (make sure to be reading the lower half of the graph which is "Reduction in exercise heart rate" as a negative scale.
As you can see the action and disposal of the succinate (indicated by the blood plasma levels) is not dissimilar to the single 100mg of succinate.
For me I get up, do my walk / cycle and or gym, which raises my HR and the relative absence of tartrate allows me to have good training time (I have a tachycardia). Then about half an hour later I'll take my metoprolol and my HR settles post exersize like it should.
I then take in the evening (its common a do the other one of walk / cycle but no gym) and can go to bed with a nice even HR
So for me and my condition I prefer that "steadying of my arrhythmia of (which I find for me persists longer than the reduction effect) and does not get in the way of (say) cycling in the day or doing work in the day. I found Succinate always left me like something was holding me back when I was on it just after surgery.
HTH
PS: one tends to need to read the pharmacokinetics carefully: for instance
from
https://www.ncbi.nlm.nih.gov/books/NBK532923/
There is significant hepatic first-pass elimination, which results in around 50% of the oral dose reaching the systemic circulation. It is 11% bound to serum albumin.
The half-life of metoprolol is about 3 to 4 hours in most patients for non-extended release tabs.[
NB the tartrate]. Metoprolol excretion principally occurs via the kidneys[
NB, so not hepatic].
[10] Metoprolol succinate produces more level drug concentrations as compared to metoprolol tartrate, which has more peak-to-trough variation. However, despite these differences in pharmacokinetics, studies have concluded that both agents produce similar clinical effects, both acute and chronic.
Wikipedia makes this note:
The different salt versions of metoprolol – metoprolol tartrate and metoprolol succinate – are approved for different conditions and are not interchangeable.
[19][20]
bottom line is that one may work for you while the other doesn't.