I rank Metoprolol 25 out of the 33 drugs I carry.

Our indication for Metoprolol is for rapid atrial fibrillation and PSVTs in patients already on oral beta blockers. We do not use Metoprolol for Acute Coronary Syndrome care. A few years back Metoprolol was considered life-saving in ACS care, but then more research came out and while it is life-saving for some patients, it is detrimental to others and the experts felt it would be too difficult for us (and I agree0 to distinguish the best candidates lacking our ability to know the patient’s ejection fractions and other considerations.

Despite not being used for ACS, I was very excited to get Metoprolol and anxious for the first time I could use it.

The patient, an elderly gentleman on Atenolol (another beta blocker), was in a rapid afib in the 160-170 range. I drew up the 5 mg of Metoprolol, pushed it slowly and waited. Nothing happened. I waited and waited. Nothing. Our next step is to call medical control, but since we were already arriving at the hospital, I just brought him on in. I gave my report, got him in the room, went and wrote my run form, came back, looked up at the monitor and saw he had slowed considerably and was in a controlled afib in the 70’s.

“So, the Metoprolol finally worked,” I said to the nurse.

“No,” she said, “We gave him Cardizem.”

After that episode I would be tempted to put Metoprolol at the bottom of my list. Here was a drug that prevented me from giving a drug that would have done the trick. But, subsequently I have talked to medics who have given the 5 mg and had it work. I have also learned that the 5 mg is often followed with another 5 mg after five minutes or so and then another 5 mg to a total of 15 mg. That usually does the trick, and if it doesn’t, well then you can go to Cardizem if the blood pressure is still decent.

And I have to ask myself, if I am on beta blockers, and I go into a rapid afib, would I rather have more beta blocker or Cardizem, which can really drop my pressure? A little more beta blocker seems the most reasonable. I just need to be prepared to call medical control and ask for additional doses if needed and indicated.


Metoprolol (Lopressor)

Class: Beta Blocker

Action: Partial blockade of Beta Receptors

Indication: Atrial fibrillation, Atrial flutter, narrow complex tachycardia

Contraindication: Hypotension (SBP < 110mmHg)
Bradycardia (HR < 70bpm)
Hypersensivity to drug
1st, 2nd or 3rd Degree Heart Block
Acute Pulmonary Edema
Recent Cocaine Use

Side effect: Pulmonary Edema

Dose: 5mg SIVP

Route: IV push (bolus) given over 5 minutes

Pedi dose: None

Important points: Utilize Metoprolol for patients experiencing narrow complex tachycardias that
are taking oral Beta Blockers.


  • Spankymedic says:

    OK, I have to ask… WHY did you even consider a beta blocker when it’s not first-line therapy for A Fib w/RVR? 5mg…another 5mg…why wait so long when AF responds nicely to a Ca++ channel blocker to begin with? Obviously if the patient was already on beta blockade therapy, my first thought would be to attempt something a bit different, as his Rx’d meds are apparently refractory. Secondly, I’ve read nothing that supports the statement that diltiazem “drops B/P”. If anything, beta blockade therapy runs a much higher incidence of secondary hypotension than do Ca++ channel blockers. “A little more beta blocker” is going to do more to drop your pressure than will Ca++ channel blockers. Hopefully this was a lesson learned.

    • medicscribe says:

      thanks for the comments-

      Here’s what our regional guidelines say as first line for “stable” rapid afib:

      Diltiazem 15-20mg SIVP (0.25mg/kg, may repeat in 15-20min 20-25mg SIVP OR Metoprolol 5mg SIVP

      These are two of the PEARLS:

      Monitor for hypotension after administration of Diltiazem.
      Utilize Metoprolol when patient takes PO Beta Blockers.

      Having only used metoprolol once, I don’t have too much experience with it. I have used cardizem quite a bit over the years and have seen pressures drop. I usually always have two lines running when I give it.

      The drug insert for Cardizem IV lists hypotension under Contraindications, Warnings and Adverse events. Curiously, the insert also says not to administer IV beta blockers and IV cardizem within several hours of each other. I will have to ask our medical Control about that.

      Our guidelines are much more aggressive that the AHA’s which says ‘consider expert consultation’ a step prior to considering cardizem of betablockers.

      I enjoy fixing the problem, but I will say I have found few of these cases that truly had to be fixed in the field. I will talk more about this when I get to Cardizem on my list.

      thanks again for the interesting points and discussion,


  • totwtytr says:

    The rule used to be that if a patient was already on a Beta Blocker, even if it wasn’t working, then Calcium Channel Blockers were out. That’s relaxed a bit, but more medical control doctors prefer that we stick with the same class of drug. We’ve run into a spate of dysrhythmias of late, including a patient in A-Fib with an accelerated Ventricular Response. Since he was already on Metoprolol, that’s what we gave him. It worked, but not all that quickly. Still, it worked. We too have removed it from the treatment protocol for ACS.

  • VaMedic says:

    Our system has both in the box and a contraindication for Cardizem is being on the beta blockers. Age is also a precaution with a stipulation to cut the dosage in half over 70yo. I have successfully used Cardizem 3 times in the last year, twice over 70, and haven’t had any success with metoprolol.

    On a side note, my father has A-fib and his cardiologist started him on beta blockers. His A-fib took off, he went to the ER, was treated with Cardizem that converted on the second dose, but dropped his rate to 28… he was released 2 days later with a follow up to his cardiologist that reccomended a pacemaker so they could more aggressively treat him with metoprolol…

    I just wish we could get the medical community to agree on stable patform to deal with common issues.

Leave a Reply

Your email address will not be published. Required fields are marked *

background image Blogger Img

Peter Canning

JEMS Talk: Google Hangout

Recent Posts
copy-medicscribeheader.png Changes September 29, 2015
medicscribeheader.png Surprises September 17, 2015
The Finger August 26, 2015
medicscribeheaderbg Assembly Line August 24, 2015
copy-medicscribeheader.png Patient Follow-up June 21, 2015
  • ems-health-safety (7)
  • ems-topics (712)
  • hazmat (1)
  • Uncategorized (426)
  • Archives
  • September 2015
  • August 2015
  • June 2015
  • May 2015
  • April 2015
  • March 2015
  • February 2015
  • January 2015
  • December 2014
  • October 2014
  • September 2014
  • May 2014
  • March 2014
  • February 2014
  • January 2014
  • December 2013
  • November 2013
  • October 2013
  • September 2013
  • August 2013
  • July 2013
  • June 2013
  • May 2013
  • April 2013
  • March 2013
  • February 2013
  • January 2013
  • December 2012
  • November 2012
  • October 2012
  • September 2012
  • August 2012
  • July 2012
  • June 2012
  • May 2012
  • April 2012
  • March 2012
  • February 2012
  • January 2012
  • December 2011
  • November 2011
  • October 2011
  • September 2011
  • August 2011
  • June 2011
  • May 2011
  • April 2011
  • March 2011
  • February 2011
  • January 2011
  • December 2010
  • November 2010
  • October 2010
  • September 2010
  • August 2010
  • July 2010
  • June 2010
  • May 2010
  • April 2010
  • March 2010
  • February 2010
  • January 2010
  • December 2009
  • November 2009
  • October 2009
  • September 2009
  • June 2009
  • May 2009
  • April 2009
  • March 2009
  • February 2009
  • January 2009
  • December 2008
  • November 2008
  • October 2008
  • September 2008
  • August 2008
  • July 2008
  • June 2008
  • May 2008
  • April 2008
  • March 2008
  • February 2008
  • January 2008
  • December 2007
  • November 2007
  • October 2007
  • September 2007
  • August 2007
  • July 2007
  • June 2007
  • May 2007
  • April 2007
  • March 2007
  • February 2007
  • January 2007
  • December 2006
  • November 2006
  • October 2006
  • September 2006
  • August 2006
  • July 2006
  • June 2006
  • May 2006
  • April 2006
  • March 2006
  • February 2006
  • January 2006
  • December 2005
  • November 2005
  • October 2005
  • September 2005
  • August 2005
  • July 2005
  • June 2005
  • May 2005
  • April 2005
  • March 2005
  • February 2005
  • January 2005
  • December 2004
  • November 2004
  • October 2004
  • September 2004
  • August 2004
  • Comments
    Thanks for the advice, love your books by the way!
    2015-09-27 04:04:59
    Keep your eyes open and your mouth shut unless you have something to say. Be nice to everyone, especially your patients. Keep showing up.
    2015-09-27 00:55:46
    The 6 Rs – The Right Drug
    You are right. I wrote the post so long ago, it is hard to remember. Perhaps I meant to write salicylates. Who knows. Good catch.
    2015-09-27 00:54:32
    The 6 Rs – The Right Drug
    ASA is not an NSAID.
    2015-09-24 12:50:52
    Hey PC, do you have any solid advice for someone new to EMS?
    2015-09-18 23:27:32

    Now Available: Mortal Men

    Order My Books


    FireEMS Blogs eNewsletter

    Sign-up to receive our free monthly eNewsletter