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atenolol 25mg... once daily?

Hi everyone. I was originally placed on atenolol 50mg once daily for hyperthyroidism associated tachycardia but was found to have an arrythmia so while my thyroid is normal now, I am staying on the atenolol but have decreased the dose to 25mg daily.

I noticed that it drops my blood pressure quite low a few hours after taking it (95/70, heart rate down to about 85 bpm), then by the next morning before taking it again, my blood pressure spikes up a little high (140/100) and heart rate in the low hundreds until I take it again.

I'd read that doses of 50mg + have 24 hour lasting effects despite a short halflife of only 6-7 hours. I am wondering if the same could be said for 25mg?

Or should I be taking this in two separate doses because of the short halflife?
Best Answer
11548417 tn?1506080564
Apart from the "half life time" and the "lasting effect", there is also the "effect is complete 6 weeks after starting taking it". So we got 6-7 hours, 24 hours and 6 weeks. I must admit that I do not completely understand it either. There is a discussion about this in the heart disease forum :

http://www.medhelp.org/posts/Heart-Disease/Exercising-with-high-blood-pressure/show/2604972

To compare blood pressures at different time of the day you will at least have to measure for a couple of days and average the results to be accurate. Otherwise other things might influence the result too much and lead to false conclusions.
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Avatar universal
I sent you a PM, Ger57....just curious about the 6 weeks thing. Thanks all for the responses... I ended up back on 50mg atenolol, my original dose. It's been 2 weeks, and while my heart rate and BP is back under control, my body still feels pretty out of whack, my periods are all messed up, I am still having migraines, etc. Feel like coming off it relatively quickly in late April really messed me up as I was on it for more than just cardiac reasons, also as a migraine preventative
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Avatar universal
I take the same as Rita when I get up in the morning, with the same result. Been on it for years.
On the odd occasion when I feel a bit 'quivery' or have been through  particularly hard day physically or emotionally I take another 1/4 tab (12.5mg) in the evening before bed. For SVT's. Without it I just couldn't do anything without my heart just taking off.....up to 220bpm. Just raising my arms above my head to change a light bulb for instance.
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221122 tn?1323011265
I, actually, take 12.5 mg of atenolol and it works great for me!  I take it for my heart rate, but after as many years as I've been on it, it no longer lowers my BP.
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11548417 tn?1506080564
I think in general you can say that the effect of medication slowly wears off. As a result from that slight variations in blood pressure over the day, due to wearing off of the medication will happen.
Taking half the dose 2x/day is probably better than 1x/day full dose for stable bp.
Question is if the benefit is big enough for accepting the extra hassle of  taking 2x/day. I still assume that in most cases the 1x/day regime is sufficient for a "fairly constant" bp.

You take Atenolol not for bp but for tachycardia. I know that Atenolol is often described 1x/day for bp lowering and 2x/day for angina. I can imagine that a big shot of the stuff is more efficient for tachycardia than 2 small shots. Therefore, if you want to change the regime, I suggest you take it up with your doctor.
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