How to dose metoprolol for chronic Afib in patients on digoxin ?

[UES Girl]

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Pt is on digoxin for CHF and left ventricular dysfunction, on metoprolol for HTN and HTN is well controlled. I'm trying to dose metoprolol XL for chronic Afib but have a few questions:

1. Koda Kimble says that beta blockers are generally contraindicated in HF patients, but it seems as if the only real contraindication seems to be that if the patient is not already on a beta blocker, agressive dosing required for afib is not recommended because of the negative inonotropic effects. But if the patient is already on a sufficient dose of beta blocker - 100 mg qd, it should be ok, right because they will tolerate it fairly well ? Plus, it's a first line therapy for chronic afib.

2. What is the nature of beta blocker dosage adjustment for someone who is on digoxin ? Pt has no renal impairement.

Thank you in advance if you take the time.

 

[naseuy]

Pt is on digoxin for CHF and left ventricular dysfunction, on metoprolol for HTN and HTN is well controlled. I'm trying to dose metoprolol XL for chronic Afib but have a few questions:

1. Koda Kimble says that beta blockers are generally contraindicated in HF patients, but it seems as if the only real contraindication seems to be that if the patient is not already on a beta blocker, agressive dosing required for afib is not recommended because of the negative inonotropic effects. But if the patient is already on a sufficient dose of beta blocker - 100 mg qd, it should be ok, right because they will tolerate it fairly well ? Plus, it's a first line therapy for chronic afib.

2. What is the nature of beta blocker dosage adjustment for someone who is on digoxin ? Pt has no renal impairement.

Thank you in advance if you take the time.

1. "There is overwhelming evidence from multiple
randomized, placebo-controlled clinical trials that beta-blockers
reduce morbidity and mortality in patients with heart failure. As
such, the ACC/AHA guidelines on the management of heart failure
recommend that â-blockers should be used in all stable patients
with heart failure and a reduced left ventricular ejection fraction in
the absence of contraindications or a clear history of beta-blocker
intolerance.1 Patients should receive a beta-blocker even if their symptoms
are mild or well controlled with diuretic and ACE inhibitor
therapy. Importantly, it is not essential that ACE inhibitor doses be
optimized before a beta-blocker is started because the addition of a beta-
blocker is likely to be of greater benefit than an increase in ACE
inhibitor dose.1 beta-Blockers are also recommended for asymptomatic
patients with a reduced left ventricular ejection fraction (stage
B) to decrease the risk of progression to heart failure."



-Dipiro

2. Start on low doses, and titrate slowly. Monitor closely.

 

[Quiksilver]

Pt is on digoxin for CHF and left ventricular dysfunction, on metoprolol for HTN and HTN is well controlled. I'm trying to dose metoprolol XL for chronic Afib but have a few questions:

1. Koda Kimble says that beta blockers are generally contraindicated in HF patients, but it seems as if the only real contraindication seems to be that if the patient is not already on a beta blocker, agressive dosing required for afib is not recommended because of the negative inonotropic effects. But if the patient is already on a sufficient dose of beta blocker - 100 mg qd, it should be ok, right because they will tolerate it fairly well ? Plus, it's a first line therapy for chronic afib.

2. What is the nature of beta blocker dosage adjustment for someone who is on digoxin ? Pt has no renal impairement.

Thank you in advance if you take the time.

Should not be doing homework over the interweb. Besides we all know that BB are only contraindicated in EXACERBATION of CHF. Titrate BB to effect slowly, titrate down on other BP meds PRN for hypotension.

What does digoxin do? What are the outcomes with patients on dig compared to those who don't use it?

What kind of regimen should CHF patients be on?

 

[ValeRx]

Take a look at the COMET trial or MERIT-HF.

 

[All4MyDaughter]

Is the patient ONLY on Dig for the HF? That's not good. Only a few BB are indicated in HF. The trials listed above are good references. What is the nature of the interaction between Dig and BB? Do you have access to Lexi-Comp or another source to explore this interaction? Once you know what the implications of the interaction are, it will be easier to decide how to handle it.

 

[UES Girl]

Should not be doing homework over the interweb. Besides we all know that BB are only contraindicated in EXACERBATION of CHF. Titrate BB to effect slowly, titrate down on other BP meds PRN for hypotension.

What does digoxin do? What are the outcomes with patients on dig compared to those who don't use it?

What kind of regimen should CHF patients be on?

I did not know that actually, that is why I asked. they brushed over it in class and the book was unclear about it- only saying it is contraindicated due to negative ionotropic effects, nothing about acute vs. Chronic HF. Homework is not graded either, so this is for my learning not for grades. 😉

 

[UES Girl]

Is the patient ONLY on Dig for the HF? That's not good. Only a few BB are indicated in HF. The trials listed above are good references. What is the nature of the interaction between Dig and BB? Do you have access to Lexi-Comp or another source to explore this interaction? Once you know what the implications of the interaction are, it will be easier to decide how to handle it.

Patient is on a whole lot of meds for hf and it was well managed. I just was specifically unclear about how to dose metoprolol in someone on digoxin because the textbook said it should be dosed differently than in patients not on digoxin but did not explain how.

 

[All4MyDaughter]

Patient is on a whole lot of meds for hf and it was well managed. I just was specifically unclear about how to dose metoprolol in someone on digoxin because the textbook said it should be dosed differently than in patients not on digoxin but did not explain how.

I can tell you my opinion but do you have access to Lexi or something like it?

 

[UES Girl]

I can tell you my opinion but do you have access to Lexi or something like it?

Not right now but Ill go on campus later on and will, so I will figure it out. 🙂Thank you for your time btw. 🙂

 

[All4MyDaughter]

Not right now but Ill go on campus later on and will, so I will figure it out. 🙂Thank you for your time btw. 🙂

No problem. 🙂

I sent you a PM.

Also is the patient on metroprolol tartrate or succinate for HTN? What dose?

 

[Ackj]

No problem. 🙂

I sent you a PM.

Also is the patient on metroprolol tartrate or succinate for HTN? What dose?

I would hope they're on XL, considering the succinate is the one that has data for heart failure. Probably on an ACE and diuretic too, so HTN should be in check.

 

[All4MyDaughter]

I would hope they're on XL, considering the succinate is the one that has data for heart failure. Probably on an ACE and diuretic too, so HTN should be in check.

I'd hope so too, but the OP didn't make it clear. Just said metoprolol for HTN. So I asked for clarification purposes...

 

[UES Girl]

I'd hope so too, but the OP didn't make it clear. Just said metoprolol for HTN. So I asked for clarification purposes...

Sorry about that, I apologize. Pt was on furosemide 20 mg bid, enalapril (don't recall the dose), spironolactone 25 mg po daily and digoxin 0.125 mg.

She was taking 100 mg po daily metoprolol XL when she presented to the ER with acute onset afib with irregularly regular heart beat and semi normal heart rates. HF was well controled except that her EF was low ~ 30 % and signs of cardiac hypertrophy on multiple tests. PMI was laterally displaced. HTN was well controlled as well, almost normotensive - ~ 122/80.

Out of curiosity, I'll share what we done as a class - again this isn't graded, this is just pbl system our school uses 🙂

We switched her to metoprolol tartrate and upped the dose to 200 mg for her afib to control the rate.
We also gave her a stroke prevention therapy - some gave her dabigatran, some put her on warfarin with heparin bridge for 3-5 days while she is inpatient.
We kept her other meds the same, since we thought further changes would be too invasive and in our theraptics course they always say 1-2 changes max at the time.

 

[group_theory]

Sorry about that, I apologize. Pt was on furosemide 20 mg bid, enalapril (don't recall the dose), spironolactone 25 mg po daily and digoxin 0.125 mg.

She was taking 100 mg po daily metoprolol XL when she presented to the ER with acute onset afib with irregularly regular heart beat and semi normal heart rates. HF was well controled except that her EF was low ~ 30 % and signs of cardiac hypertrophy on multiple tests. PMI was laterally displaced. HTN was well controlled as well, almost normotensive - ~ 122/80.

Out of curiosity, I'll share what we done as a class - again this isn't graded, this is just pbl system our school uses 🙂

We switched her to metoprolol tartrate and upped the dose to 200 mg for her afib to control the rate.
We also gave her a stroke prevention therapy - some gave her dabigatran, some put her on warfarin with heparin bridge for 3-5 days while she is inpatient.
We kept her other meds the same, since we thought further changes would be too invasive and in our theraptics course they always say 1-2 changes max at the time.

First - why is she on digoxin? What was the reasoning? Was it because the previous docs encountered hypotension while trying to rate control her? Perhaps she has sick sinus syndrome and people are afraid of going up on a beta-blocker? Was she someone who has severe HF and needed some ionotropic support in order to appropriately diurese? Is it mainly for symptomatic relief?

Second - you mentioned she presented in afib, but I'm not sure what you mean by "semi-normal heart rate". If she is in afib, she will definately have irregular irregular heart beat. If she was in RVR, then I can see going up on her beta-blocker. However, if her HR is reasonable, then I see no reason to change her rate control meds since she is being appropriately rate control*

Third - your group proposed going from Toprol XL 100mg daily to Lopressor 200mg? That's a pretty big increase - especially someone who is already digitized, and on diuretics (risk of not only bradycardia, hypotension, but also orthostatic hypotension + fall)

Fourth - does she have HTN? If yes, CHADS2 score of 2. If no, CHADS2 score of 1. Don't really understand the rationale for dabigatran, coumadin and heparin bridge given simultaneously. If the only reason for anticoagulation is for her afib, and she doesn't have a history of stroke, PE, or DVTs, then I would have placed her on coumadin without heparin bridge (and let her INR drift up to 2). Dabigatran is too new, likely won't be covered by insurance, effectiveness can't be monitored (especially if she is also on a PPI), and if she were to fall and bleed, or need surgery (whether emergent or elective), no one knows exactly how to reverse. If compliance is an issue, she is on a polypharmacy regiment for her chronic systolic heart failure - there are more things to worry about than anticoagulation compliance.


*if she is still symptomatic from her heart failure despite being adequately rate control, I would increase her beta-blocker, and would probably consider a referral to EP for an ICD placement (mainly primary prevention) but also will give me leeway in pushing the dose of her beta-blocker without having to worry about bradycardia.

 

[All4MyDaughter]

CHADS 2 score = 2 (she does have hypertension) so warfarin therapy seems to be indicated. You don't typically bridge warfarin in new onset afib. I don't like dabigatran. My reasons pretty much match group_theory's.

Chebs, I don't understand the rationale for the switch from metroprolol succinate to metoprolol tartrate. Succinate is indicated in heart failure and tartrate is not. Are you familiar with the trials someone mentioned upthread? And why the huge dose increase in metroprolol?

What about the interaction you mentioned earlier between metoprolol and digoxin? What did you find out about that?

 

[rxlea]

I love these threads. 🙂

(I am being serious. They are my favorites.)

 

[UES Girl]

CHADS 2 score = 2 (she does have hypertension) so warfarin therapy seems to be indicated. You don't typically bridge warfarin in new onset afib. I don't like dabigatran. My reasons pretty much match group_theory's.

Chebs, I don't understand the rationale for the switch from metroprolol succinate to metoprolol tartrate. Succinate is indicated in heart failure and tartrate is not. Are you familiar with the trials someone mentioned upthread? And why the huge dose increase in metroprolol?

What about the interaction you mentioned earlier between metoprolol and digoxin? What did you find out about that?

Sorry I didn't make it clear, again my apologies, this discussion and conclusion was during the day time before you sent me a link. 🙂

We were told that she was started on digoxin for HF even though her other meds like diuretics weren't titrated up to a ceiling, because sometimes physician start pt on digoxin when they have CHF with either S3 or LV dysfunction (she had the latter) and we have no authority to discontinue the regimen. Plus she had no edema, so I wouldn't even think it would be appropriate to titrate diuretics because of the risk of over diuresis and with spironolactone - her potassium was sort of on the higher side ~ 4.6, so not sure if titration would be in order there either. We were trying to manage her HF therapy and treat her acute afib at the same time.

Her RVR was 120 and the COR indicated irregulaly irregularly HR, but we were told that as long as HR is < 160, it's sort of ok, semi-normal and only rate control is sufficient ( meaning rhythm control is not indicated enough if that makes sense), is that wrong ?

Her CHAD score was 3 based on her age too, that is why we felt she needed a stroke prevention therapy, because we were taught if chad score > 2 => need stroke prevention therapy. We gave either warfarin + heparin bridge OR some people gave dabigatran because they presented it in class as a miracle super drug that can be easily renally dosed but now after reading the last post I realize we are mistaken. 🙂

The interaction to look up and the amazing studies to look up everyone was kind enough to provide is first on my agenda tomorrow, I am studying CAD today. 🙂

 

[group_theory]

Sorry I didn't make it clear, again my apologies, this discussion and conclusion was during the day time before you sent me a link. 🙂

We were told that she was started on digoxin for HF even though her other meds like diuretics weren't titrated up to a ceiling, because sometimes physician start pt on digoxin when they have CHF with either S3 or LV dysfunction (she had the latter) and we have no authority to discontinue the regimen. Plus she had no edema, so I wouldn't even think it would be appropriate to titrate diuretics because of the risk of over diuresis and with spironolactone - her potassium was sort of on the higher side ~ 4.6, so not sure if titration would be in order there either. We were trying to manage her HF therapy and treat her acute afib at the same time.

Her RVR was 120 and the COR indicated irregulaly irregularly HR, but we were told that as long as HR is < 160, it's sort of ok, semi-normal and only rate control is sufficient ( meaning rhythm control is not indicated enough if that makes sense), is that wrong ?

Her CHAD score was 3 based on her age too, that is why we felt she needed a stroke prevention therapy, because we were taught if chad score > 2 => need stroke prevention therapy. We gave either warfarin + heparin bridge OR some people gave dabigatran because they presented it in class as a miracle super drug that can be easily renally dosed but now after reading the last post I realize we are mistaken. 🙂

The interaction to look up and the amazing studies to look up everyone was kind enough to provide is first on my agenda tomorrow, I am studying CAD today. 🙂

If she doesn't show signs of fluid overload, then not going up on her diuretics is the appropriate step. It seemed she became symptomatic from her afib, so appropriately treating her afib should improve her symptoms. I would actually titrate her beta-blocker in this case. If she is very symptomatic from her afib, then I would consider elective cardioversion (either after a month of anticoagulations OR after a TEE to confirm absence of a thrombus)

For atrial fibrillation, you will almost never see HR > 160. Usually if it is less than 110 I'm less concern, but my goal is to get it under 100, and if I can get it under 80, all the better.

As for your question on rate control versus rhythm control, I would read the conclusions from the AFFIRM trial

As for digoxin, there is usually a rationale for why patients are on certain drugs. She has heart failure so I would expect LV dysfunction (especially with an EF of 30%). Having a S3 wouldn't be surprising to me either.

American College of Cardiology (ACC) and American Heart Association (AHA) joint guidelines for managing chronic heart failure in adults recommend administering digoxin to improve symptoms in patients treated with diuretics, ACE inhibitors, and beta blockers

Digoxin should be considered for patients who have symptoms of heart failure (NYHA class II-III, Strength of Evidence = A and NYHA class IV, Strength of Evidence = C) caused by left ventricular systolic dysfunction while receiving standard therapy.



Hunt SA. ACC/AHA 2005 guidelines for the diagnosis and management of chronic heart failure in the adult: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines
J Am Coll Cardiol. 2005;46:el&#8211;82.

 

[All4MyDaughter]

Once again, agree with group_theory. You don't max out diuretics unless symptoms of fluid overload are present. It is normal to titrate ACE inhibitors and BBB to max tolerated doses as part of HF management. Chebs, you mentioned spironolactone. At 25 mg/day, it's not being used as a diuretic. It's being used as an adolesterone antagonist. The typical dose is 25 to 50 mg/day in HF. Diuretic doses are much larger. The study supporting the use of spirononlactone/adolesterone antagonist in HF is (I believe) the RALES trial. Digoxin is not considered first line therapy in HF. Its appropriate place is typically for symptom control after patients have been maxed out on other appropriate therapy first. Digoxin does not improve mortality in HF but does reduce hospitalizations.

I'm still confused about the patient's HR but agree with group_theory that it's best to get it below 80 to 100 in HF and Afib. With the additional information you supplied, I'm more certain that ever that you should NOT switch from metoprolol succinate to tartrate in this patient. I agree with group_theory that increasing the BB dose to control the HR (achieve better rate control) is probably a good plan.

If she did need rhythm control, there are a couple of anti-arrhythmics that are considered appropriate/safe to use in HF. I'm not sure how much of this you've already been taught, but I can elaborate if need be.

Getting back to your original question about the interaction between metoprolol and digoxin, it's not so much an issue of adjusting the BB dose but rather monitoring the effect of the combination on the patient and keeping track of serum digoxin levels, since they could possibly increase. To me, the BB is the more important component of this patient's therapy, so if there is an issue tolerating the higher BB dose and the digoxin, I'd probably reduce the digoxin dose. This is just my impression based on the limited info we have about this patient.

 

[pfaction]

I'd like to know which anti-arrhythmics are good in HF. I want to say class 1B but I'm just guessing, since they speed up conduction? (I think).