Pushing 50mg of IV Lopressor? Tell me no !

Trauma Columnist · Jul 29, 2006

Am not sure what it would be for outpatient nursing, but for an acute MI patient or unstable angina, the protocol is 5mg every 5 minutes x3 doses to keep heart rate around 60 bpm to reduce the cardiac stress. Lopressor's half-life is very short which is why it isn't given for long-term BP control via the IV route.

Long Term Care Columnist / Guide · Jul 29, 2006

FIFTY mg??!! :eek: I've pushed as much as 15 mg over a 15-minute stretch, but I'm afraid fifty would drop someone like a rock. WOW. I'm with you, Dutchgirl..........I wouldn't give that much Lopressor either, at least not outside an ICU or critical care setting. :eek:

Editorial Team / Admin · Jul 29, 2006

The Lopressor should be titrated for effect, not just "give 50 mg." The end point is to get the heart rate between 50 and 60, for optimum imaging, like for a chest or cardiac CTA (Computerized Tomography Angiogram, or CT Angiogram). If the heart rate falls within the target range after 15 mg IV Lopressor, then no more is given and the patient is quickly imaged, taking full advantage of the medication-induced bradycardia (read: image quickly, before the Lopressor wears off). The patient should be monitored at all times: LOC, NIBP, continuous EKG for HR , RR . . . and as this test IS a Cardiac Stress Test, a crash cart should be in the area (preferably in the room), well-stocked and available at all times, with an ACLS-trained RN and knowledgeable support staff in attendance.

What I'm trying to say is, yes the IV dose given for this test can be higher than routinely given in the ICU. Protocol should clearly outline the maximum dose that may be given, and the patient should be closely monitored while the med. is titrated. (my Epocrates program says, for acute MI, to give 5mg q 2 min X 3 doses, then in 15 min give 50mg (po))

Anecdotally, I've heard our Cardiologist (who does CTAs) tell of some pts whose heart rates didn't respond at all to the max dosage (50mg), with no sequelae. They're imaged anyway, with less-than-desired imaging.

DutchgirlRN, ASN, RN · Jul 30, 2006

I realize that 50mg is not given all at once. On the floor we give 5mg Q4 hours for patients who are NPO so it must not leave the body too quickly. If the doctor wants me to push 5mg of Lopressor every 5 minutes over almost an hour time period I'm afraid I would have to refuse or let the doc push it himself.

I can imagine what could happen to the patient an hour or two later when at home or God forbid driving. I hoped I'm not faced with this because I would quit first.

I've been a nurse for 31 years and have pushed tons of IV meds but have never heard of such an outrageous dose! We use Versed in MRI and monitoring their VS it very effectively relaxes the patient and lowers the HR.

steelydanfan · Jul 30, 2006

The pt. subsequently needs to be monitored in the PACU or RR for at least 1 hour post proceedure. In my experience, if it doesnt work after 3 5mg doses q5 mins, another drug might be a better bet.

Editorial Team / Admin · Jul 30, 2006

The dosage question, then, needs to be addressed through Nursing and possibly through Risk Management, questions answered, protocols written and followed (committee of Cardiology, Pharmacy, Nursing and Radiology).

vandebar · Mar 5, 2007

Patients having a coronary CTA either inpatient or outpatient may receive up to 5 doses of metoprolol to bring the HR down or below 60. Our policy is 5mg IVP over 2 minutes. The patient is monitored for 5 minutes and the 2nd dose is given if indicated. Monitoring again for 5 minutes and then repeated for a total dose of 25 mg IVP. There has been occasions when the cardiologist ups this to 6 or 7 doses. (Our standing order is for 5). There are also times when the cardiolgist may switch to diltiazem after exhausting the betablocker. This will usually not exceed 2 doses of 10 mg each. I felt the same way when I started in CTA & felt like this was a LOT. It is very well tolerated and I have had no adverse sxs with any patient receiving the betablockers or calc channel blockers.

AnnieOaklyRN, BSN, RN, EMT-P · Mar 5, 2007

was this someone speaking to you? maybe they said 15 mg which is the normal total dose, and not 50.

Swtooth

DutchgirlRN, ASN, RN · Apr 23, 2007

It's definately 50mg of IV Lopressor given 5mg per push for a total of 50mg as needed to bring the HR down. My experience has been if the HR does not go down sufficiently after 3 doses the remaining 35mg does nothing. The test is done anyway. I've since learned this is common practice where CTA's are done.

Radnurse54 · Jun 13, 2007

About 1 1/2 years ago I worked in a Radiology department where a cardiology group was starting up a CTA program, I have to tell you as an ER nurse the amount of Lopressor in their protocol concerned me too, however, the cardiologists and 2 nurses who worked with their protocol at another hospital came and we did scans on 25 volunteers to get us more comfortable with the protocol. We gave up to 50mg of IV Lopressor and I did a lot of research and talking with the pharmacists etc. We had very specific criteria for the meds and we gave 5 mg over 2 minutes with VS done q3minutes during the giving of meds and q5 minutes after meds completed up to 30 minutes. We kept our outpatients until they returned to baseline/30-60minutes post test. Outpatients had to come with a driver and were also made NPO for the possibility of nausea/vomiting related to the large bolus of contrast. Inpatients who were NOT on a monitored floor (didnt happen often) we also kept for the same time like the outpatients.

I once gave 70mg of Lopressor with the Cardiologist standing in the room but the patient never responded to the medications. We also had standing orders for treatment of bronchospasms/bradycardia etc. We actually found that the patients receiving oral Lopressor the night before and the morning of had better outcome with less medications. Those patients also had to have a driver for the exam.

KnittingRN7 · Jan 19, 2008

I work in a cardiologist owned clinic with a 64 slice ct scanner. Our current protocol is to give 5mg to 40mg of metoprolol IV to get the HR less than 70 or 65 for certain protocols. If asthmatic, we can give up to 25mg of IV cardizem, if still no effect 20mg of metoprolol in addition to the cardizem. This is a protocol dictated by our cardiologist. It also concerns me but he and others tell me that it is common practice, I just can't seem to find those protocols in writing. I am so happy to find this site.

Unfortunately we only have 1 nurse scheduled and pt's are scheduled every 30min, so needless to say when things don't happen quickly or we need to watch them longer we can get behind. Our pt's do not always have a driver and it is not mandatory at this time. This is a fairly new dept and we are learning. I appreciate any help or expertise you all can give us. :bugeyes: