When vagal maneuvers fail to terminate stable narrow-complex SVT, the primary medication of choice is adenosine. For the unstable patient with a regular and narrow QRS complex, adenosine may also be considered prior to synchronized cardioversion.
Adenosine is the primary drug used in the treatment of stable narrow-complex SVT (Supraventricular Tachycardia). Now, adenosine can also be used for regular monomorphic wide-complex tachycardia.
When given as a rapid IV bolus, adenosine slows cardiac conduction particularly affecting conduction through the AV node. The rapid bolus of adenosine also interrupts reentry (SVT causing) pathways through the AV node and restores sinus rhythm in patients with SVT.
When injected into the body, adenosine is rapidly absorbed by red blood cells and blood vessel endothelial cells and metabolized for natural uses throughout the body. In light of this adenosine should be administered by RAPID intravenous bolus so that a significant bolus of adenosine reaches the heart before it is metabolized.
A change from the 2010 guidelines now has adenosine given up to two times rather than three.
Dosing
The first dose of adenosine should be 6 mg administered rapidly over 1-3 seconds followed by a 20 ml NS bolus. If the patient’s rhythm does not convert out of SVT within 1 to 2 minutes, a second 12 mg dose may be given in a similar fashion. All efforts should be made to administer adenosine as quickly as possible.
A lower initial dose of 3mg should be used for patients taking dipyridamole or carbamazepine as these two medications potentiate the effects of adenosine.
Also, prolonged asystole has been seen with the use of normal doses of adenosine in heart transplant patients and central line use. Therefore, the lower dose (3mg) may be considered for patients with a central venous line or a history of heart transplant.
Precautions
Some side effects of adenosine administration include flushing, chest pain/tightness, brief asystole or bradycardia.
Make sure that adenosine is not used for irregular, polymorphic wide-complex tachycardia and unstable VT. Use in these cases may cause clinical deterioration.
Return to ACLS Drugs Main Page.
Dr Vishnu Patil says
What is the adenosine maximum dose ..???
Jeff with admin. says
I have not seen any set dose for a maximum. I have seen literature that suggested the use of up to 18mg in a peripheral IV. Personally, I have only seen up to 12mg given in a single dose. I can tell you that the higher the dose, the longer the asystole will last so I could say that for general purposes, 12mg should not be exceeded without expert consultation from a cardiologist.
As far as cumulative maximum dose this is not a cumulative max dose. Adenosine does not build up in the system and is metabolized very rapidly by every cell in the body.
Kind regards, Jeff
Dr. Asim says
As per ACLS protocols, is adenosine contraindicated in asthma patients with supra ventricular tachycardia?
Jeff with admin. says
AHA does not address this issue. Here is an article that addresses this. Adenosine and Asthma
I think that in the situation, it would be a professional clinical decision that the provider would have to make. If they truly thought that the adenosine was necessary and all other methods converting the SVT were insufficient then it seems that the use of adenosine could be justified.
Kind regards,
Jeff
Dr Smita Mishra says
What is the effect of adenosine on babies presenting with HR >180, 1:1 AV conduction and short PR interval ?
Jeff with admin. says
I am definitely not an expert in pediatric cardiology, but I can direct you to an article that covers this: Neonatal Tachycardias
gabriel Adeaga says
What is Adenosine Cardiolite.?
Jeff with admin. says
You are referring to adenosine/cardiolite stress test. Here is a summary of the procedure:
“The patient will receive the medication adenosine through the IV, replacing the exercise portion of the test. After three minutes of the adenosine infusion, the tracer will be injected via the IV. Images will be obtained an hour and a half after the cardiolite injection. The medication adenosine will dilate the heart’s arteries. If the heart’s arteries are healthy they will dilate more than arteries that are not healthy. The patient may feel flushed, chest pressure or pain, shortness of breath, and or headache.”
Kind regards,
Jeff
Kevin says
If Adenosine has such as short half life and should be given as quickly as possible through an IV that is closest to the heart, why would you reduce the dose to 3mg if it is given through a central line. This seems contradictory.
Kevin
Jeff with admin. says
Central line catheter tip placement is in the superior vena cava right at the entrance of the heart.
The higher dose of adenosine (6 mg/12 mg) given through a central line has been know to produce prolonged asystole.
3 mg injected through the central line directly into the heart has been shown to produce the effect needed to terminate SVT.
Kind regards,
Jeff
Dr sunil says
Sir
If we give through femoral central line than what will be dose of adenosine
Jeff with admin. says
There is no recommended dose and this would need to be at the discretion of the physician. Personally, I think that the AHA guidelines would be fine. The half-life of adenosine is 5-10 seconds. Give 6mg monitor for effect. If it does not work go up to 12 mg. Keep it simple.
Kind regards,
Jeff
gahoma says
actually i experienced this , prolonged asystol after 6mg adenosine given via central line ,,,,,,,,, and we was planning to start CPR . thanks for valuable information and knowledge
Christina says
Hello! I was wondering if adenosine has an effect in VT (not only in SVT with abberancy, which looks like VT) and if so, what is the mechanism?
Jeff with admin. says
Fast rhythms of the heart that are confined to the atria (e.g., atrial fibrillation, atrial flutter) or ventricles (e.g., monomorphic ventricular tachycardia) and do not involve the AV node as part of the re-entrant circuit are not typically converted by adenosine.
However, the ventricular response rate is temporarily slowed with adenosine in such cases. Adenosine’s mechanism of action is related to transient heart block of the AV node. Kind regards, Jeff
Felipe says
Hi guys, have you encountered some data/literature that in giving Adenosine via a distal peripheral line (aside from the ideal antecubital site) the dose should be doubled? Like you start it at 12mg then 24, 24?
Thanks.
Jeff with admin. says
I could not find literature out there specifically looking at distal peripheral line use and higher dosing. I did not see any positive information about the use of 24mg. However, 18mg in one study had a 95% conversion rate:
Higher doses of adenosine for SVT
The article below has to do with the use of high dose adenosine for refractory SVT.
High dose adenosine for refractory SVT
Some EMS and cardiologists recommend starting with 12 mg of adenosine rather than 6mg. There is a 65% conversion rate with 6 mg and 90% conversion rate with 12 mg.
As far as I can tell, the higher peripheral antecubital site is the recommended IV position for the administration of adenosine for SVT conversion.
Kind regards,
Jeff
Lauren says
In the case of NCT would you use synchronised cardioversion first or adenosine cardioversion first?
Jeff with admin. says
You may attempt adenosine first even if the patient is stable or unstable with NCT. However, per a providers discretion, interventions may be tailored to the patient’s condition. In some cases with very unstable NCT, moving directly to cardioversion and bypassing adenosine would be considered the best intervention for the patient’s condition.
Kind regards,
Jeff
Katie says
Just wondering since it has been a little while since I’ve taken ACLS. I have always practiced having the patient who we are going to be administering adenosine hooked up to the defibrillator. Is this something that is part of the ACLS protocol as something that should be done? I was taught that it was a necessity, not just a recommendation. Thank you!
Jeff with admin. says
It is not necessary to attach the patient to a defibrillator when giving adenosine. This is not a recommendation. However, the patient should be monitored throughout the procedure and the crash cart/defibrillator should be readily available.
You may want to check your hospital policy. Many hospitals have different policies and you just need to make sure and follow policy. I have seen a lot of people converted with adenosine and I have never seen a patient code after adenosine administration.
Kind regards, Jeff
Jule K Jossi says
Hi,
Just wondering whether adenosine is safe to give to pregnant woman in an outpatient clinic with crash cart readily available and patient is connected to the crash cart monitor. Patient’s heart rate was 160, and complaining of palpitation.
Do you think this patient should have to transfer to emergency for adenosine?
Thanks,
Julie
Jeff with admin. says
Adenosine is safe for use during pregnancy. However, it would be a wise clinical decision to treat any patient that has SVT in a controlled setting (i.e. emergency room) with experienced providers if it is feasibly possible. Transferring the patient to a higher level of care would be the more prudent choice.
Kind regards,
Jeff
Kathy123456 says
I am confused about when to use adenosine vs cardioversion in the unstable patient. The book says (p116) if the pt. is unstable due to tachycardia “immediate synchronized cardioversion is indicated”, but the algorythm says (box 4) “synchronized cardioversion….if regular narrow complex consider adenosine”. So, are there times that adenosine is a better choice than cardioversion (besides the time involved in getting the machine ready)? I would imagine this would be true if the atrial fib/flutter were long standing, but that may be hard to know in an emergency situation. Also, this site seems to indicate that adenosine is only indicated in the stable patient.
thanks
Jeff with admin. says
The administration of adenosine for anything unstable does require some clinical judgement on the part of the provider treating the patient. The best choice when is doubt is to use synchronized cardioversion for unstable tachycardia. You are correct there are some instances (atrial fibrillation/flutter) where adenosine may be a better first choice. Also, there are other things that would need to be done in these situations before cardioversion could take place.
Adenosine may be used for unstable tachycardia when the tachycardia has a regular narrow complex. Clinical judgement would dictate when this should take place. This is borderline beyond the scope of ACLS. The effects of adenosine of pretty short-lived and it is a viable option in this situation.
Kind regards,
Jeff
whitej1 says
Sorry if this question has been answered elsewhere and thanks for your input in advance.
I’m trying to determine push rates for the ACLS drugs. I realize that adenosine must be pushed quickly, but for all of the other drugs, how fast should they be pushed. I’m trying to figure out if there is specific harm in pushing too fast (or too slow).
-Jon
Jeff with admin. says
When providing drugs during cardiac arrest, the medications are to be pushed as rapidly as possible and followed with a 20 mL normal saline flush as rapidly as possible.
There will not be any harm by rapid pushes and this rapid push will bolus the drug into the system and provide the medications effects as rapidly as possible to the patient’s cardiovascular system.
So, during cardiac arrest you can give the medication as fast as you can push the plunger on the syringe without causing damage to your IV or central line.
Kind regards,
Jeff
Hilgendh says
Thanks! I’ve been trying to figure this out too! In my “Fast Facts for Critical Care” book, I read that amiodarone should be pushed over 3-5 mins, followed with rapid 20cc NS, and separated by 3-5 mins. But I haven’t found that instruction anywhere else. Would there be any reason to do it this way? or is this just wrong? It seems like a long push time.
Somewhere else I read that Adenosine has to be given with a 3-way stop cock to ensure it is given fast enough. Is this accurate ?
Thanks for your help and expertise!
Jeff with admin. says
In a code situation there would not be any reason to push the medication slowly. It is wrong. If the patient is not in cardiac arrest then the medication can be pushed slowly over 3-5 minutes. The patient is in cardiac arrest, you are rapidly doing everything possible to revive them. Push the medicaton as fast as possible and follow it with 20 ml of NS.
Adensoine is give to paitents in SVT. Adensoine metabolizes in just seconds so it must be pushed as fast as possible and then followed with 20 ml of NS as fast as possible. A 3 way stop-cock help with the speed of getting the NS in after the adensoine is pushed. If possible, use a 3 way stop-cock.
Kind regards,
Jeff
Michelle says
Are there any other reasons why adenosine wouldn’t be effective, (other than adenosine being metabolised too fast/ not a fast enough push)?
Jeff with admin. says
Generally speaking every person will respond somewhat differently depending on a number of metabolic, physical, and chemical factors. Also, the type of narrow complex tachycardia will determine its success. Kind regards, Jeff
Lauren says
It wouldn’t be effective if the rhythm is not dependent on the AV node (to exist, not to be propagated). For example, sinus tachycardia is not a re-entrant rhythm but it uses the AV node to activate the ventricles so adenosine would briefly interrupt it but it would recur right away. Same with atrial flutter and atrial tachycardia. Rhythms that use the AV node to cycle, re-entrant rhythms, ‘should be’ sensitive to adenosine (if given properly). So if you give it, the ventricular rate falls and then comes right back, question your diagnosis (if possible, have a 12 lead ecg recording as you give the adenosine, very helpful to unmask atrial activity once the noise of the QRS is suppressed). There are exceptions to this, a minority of SVT’s are stubborn and resistant to adenosine but might respond to other AV agents like verapamil.
Jeff with admin. says
Thanks for adding some clarification on that Lauren. Kind regards, Jeff
Claire Smith says
My daughter has SVT and had adenosine administered today ( the third time in the last 4 months) and I attended hospital with her. The first dose increased her heart rate from 198 to 215 before reducing to 194, the second dose increased her heart rate to 218. The staff, including a doctor and junior doctor, said they had never seen this reaction before and left the cubicle to discuss and then telephone for advice. A third dose of adenosine was then administered, which reduced her heart rate to 130, and, after maintaining this rate for a further hour, she was discharged. I have two questions:
Why did the adenosine cause the sudden increase in heart rate, on two consecutive occasions
and
Had the third dose not worked, what would have been the next course of action?
Thank you
Jeff with admin. says
I cannot give any medical advice, but I can answer your questions since these are not specifically asking for medical advice.
1. I have no idea why adenosine would do that. Adenosine should not cause an increase in heart rate. I bet the physicians were stumped.
2. If the third dose had not worked, I’m sure that they would have referred her to a pediatric cardiologist. They probably would have admitted her to the hospital for observation. Depending on her age, the HR of 130 that she was discharged with is still kind of high.
Kind regards,
Jeff
Nick says
Hi..
This is a very interesting page with some excellent information. Claire’s question above has prompted me to enquire about something similar that I experienced with Adenosine.
Whilst undergoing tests to determine if I had an accessory pathway, my cardiologist arranged an Adenosine test. At the time of the test, I had a normal rhythm and was injected with increasing amounts which I think were 3, 6, 12 and 18mg. It was an absolutely horrendous experience but thankfully short lived. I recall holding the nurse’s hand for comfort as it was quite unpleasant. Anyway, each time I was injected, my heart rate increased considerably which surprised the cardiologist somewhat. A few weeks later, the test was repeated with the same doses and the same result with the increased heart rate.
I still haven’t received an adequate explanation of why the Adenosine affected my heart in that way.
I still experience regular palpitations and ‘flutterings’, some of which cause quite a bit of discomfort. However, as of yet, only PVCs have been detected on ECG so the cardiologist was satisfied that everything is ok.
I appreciate that you’re unable to provide medical advice but I am interested in your thoughts about the Adenosine test.
Thanks for any help…
Nick
Jeff with admin. says
Thanks for sharing your story. I’m not sure what is happening and I have never see a paradoxical reaction with adenosine as you described. I believe that a syndrome called Wolf Parkinson White (WPW) can cause this to occur, but I have never seen it.
The best thing to do would be to have a 12-lead EKG running while you are actively receiving the adenosine. This would tell you much more about what is occurring.
Sorry I cannot be of more help.
Kind regards,
Jeff
cindy says
I heard on an ED podcast recently that you can put the Adenosine in the 20 cc flush and push it fast, and that it works. I am researching this…has anyone tried it?
Jeff with admin. says
I have not heard of this. It would seem counter intuitive to how adenosine as a bolus works. The reason why it is given rapid IV push is to decrease the amount that it is diluted as it is bloused into the system. It would seem that diluting adenosine prior to administration would reduce its effectiveness.
Kind regards,
Jeff
gen says
hi jeff,
I’m a first time ACLS-er and our instructor told us that after rapid administration of adenosine + rapin 20 ml NS via peripheral line we should elevate the hand to facilitate faster flow of the drug towards the heart. Is this a proven practice and is it effective?
Jeff with admin. says
Raising the arm for adenosine administration is an unproven practice. Much more important would be placement of an IV as close to the heart as possible. The IV should be place in the antecubital area or above. The shorter the distance to the heart, the better. This will ensure that the bolus is not fully metabolized before it reaches the heart. Every cell in the body can metabolize adenosine (think ATP) there rapid IV bolus as close to the heart as possible is best.
Kind regards,
Jeff