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.
Katharibe says
So adenosine is okay for SVT, Sinus Tachycardia, and A Flutter.
But not for A Fib.
And obviously never for V Tach or V Fib.
Is that correct?
Jeff with admin. says
When adenosine is given, it blocks/slows conduction of electrical impulses through the AV node for a short period of time.
The rapid bolus of adenosine also interrupts reentry (SVT causing) pathways through the AV node and restores sinus rhythm in patients with SVT.
Adenosine is not used to correct sinus tachycardia, atrial fibrillation, or atrial flutter.
Patients with irregular heart rates, especially atrial fibrillation, patients with PSVT mimics such as atrial flutter with 2:1 conduction or sinus tachycardia in a dehydrated or stressed patient should never receive adenosine. Also, Adenosine should never be used in wide irregular tachycardias
Kind regards,
Jeff
John says
Where is the best place to administer adenosine? Or does placement of iv even matter?
Jeff with admin. says
Any peripheral site that is close is closer to the central circulation is acceptable. On or above the Antecubital area is ideal.
Kind regards, Jeff
Jason says
AC or above, EJ if they have it
Cindy says
What drugs are contraindicated in PSVT?
Jeff with admin. says
There are no absolutely contraindicated medications. However, any medications that are going to increase heart rate (i.e. epinephrine) would be avoided.
Kind regards,
Jeff
Jordha dathees says
After the second dose of adenosine still the SVT is not revert with stable patient, what is the next treatment
Jeff with admin. says
A third dose of 12 mg of adenosine can be given. If conversion still does not occur after this then expert consultation should be obtained and most likely be next intervention will be synchronized cardioversion.
Kind regards,
Jeff
Jason says
Cardioversion and if the QRS is narrow it has to be done quickly
Maria says
I noticed that you stated not to use adenosine in the event of a-fib. However our protocol has adenosine as a first line drug .
Just wondering about this .
Jeff with admin. says
Adenosine is contraindicated when atrial fibrillation is present. Adenosine can have a pro-arrhythmic affect and can lead to rhythm degeneration.
If you are correct and your protocol for atrial fibrillation includes adenosine then someone has made a serious error in the development of the protocol.
Here is an article which covers the adverse affects of adenosine when certain arrhythmias, including atrial fibrillation, are present. Article
Kind regards,
Jeff
Kristi says
If a patient has a central line and the initial dose is reduced to 3mg, should the 2nd dose also be reduced? So only 6mg or can they get the full 12mg after the 3mg dose failed? Thanks!
Jeff with admin. says
There would be some physicians that would just go directly to the 12 mg.
There will be other more conservative physicians that would attempt 6 mg instead of the 12 mg.
Giving a bolus dose of adenosine through a central line at the normal dosage would increase the length of time that the person remains in asystole while the heart’s electrical system resets.
This typically would not be a problem, but the feeling of the heart stopping can be quite uncomfortable and scary. There is a possibility that the person might even experience symptoms of cardiovascular instability. (syncope, dizziness, chest pain)
Kind regards,
Jeff
eyla says
when started for 6-12-12??
Jeff with admin. says
The change occurred when the American Heart Association updated the ACLS guidelines in 2015.
Kind regards,
Jeff
Regena says
Is it ok to give 3 doses of adenosine? 6-12-12?
Jeff with admin. says
yes it is OK to give three doses of adenosine.
Kind regards,
Jeff
E says
Is it ever OK to give 12 mg first and skip the 6 mg dose?
Jeff with admin. says
In some cases when 6mg has in the past failed to convert a patient out of SVT, it may be decided to start with 12 mg rather than 6mg.
Kind regards,
Jeff
Ee.nu says
I would like to know ..Is it indicated to keep patient on face mask oxygen while adminstring adenosine for SVT patient ?
Jeff with admin. says
It is not necessary to keep a patient on a face mask while administering adenosine for SVT.
Whatever oxygen is necessary to maintain an oxygen saturation greater than 90% is sufficient.
Kind regards,
Jeff
Nat says
If you were given the full 30mg of Adenosine and it worked… and some time later you had a SVT episode, how much time is advised before another 30mg of Adenosine can be administered?
Anyone have any info on this? I couldn’t find any.
Thanks, Nat
Jeff with admin. says
30 mg is a lot of adenosine. The standard dose is 6 or 12 mg.
However, to answer your question, if you received 30 mg of adenosine this would be metabolized very rapidly. The half-life of adenosine is 30 seconds. If you gave 30 mg of adenosine, this would prolong the episode of asystole that adenosine causes. It would not be recommended.
That said, you would probably be safe to give a second is three or four minutes later.
I have never seen any recommendation for adenosine at a dose over 18 mg.
Kind regards,
Jeff
gabriel says
Methylxantines such as theophylline and caffeine can inhibit the A1 receptor and thus inhibit or completely block the action of Adenosine.
Sometimes high doses as 30 mg of Adenosine may be required in case of theophylline or caffeine users.
Jeff with admin. says
Thank you for sharing this.
Kind regards,
Jeff
Kate says
Is it necessary or “best practice” to elevate the arm when using AC peripheral line to give adenosine push?
Jeff with admin. says
It is not necessary or best practice to raise the arm when administering IV adenosine. AHA does not recommend this, but it is not contraindicated. Adenosine should simply be pushed as rapidly as possible and be followed with 20 ml of NS as fast as possible. This process is made much faster with a stopcock is used so that both the adenosine and the 20 ml flush are connected at the time of administration. Kind regards, Jeff
Sandra Taylor says
I can tell you from personal experience that as the patient in SVT raising the arm certainly feels much better. In 2016 l was administered the drug (12 mg.) in the ER 16 times and twice in an Ambulance. I certainly think it helps and when the nurse didnt do it once…l asked her to do it.
I am a very greatful patient ????
Jeff with admin. says
Thank you for sharing that Sandra.
Eric says
I was giving an adenosine stress test the other day and the patient started sneezing one after another with no breaks before going into a block. Is this sneezing always a precursor that someone is going into a block?
Jeff with admin. says
Sneezing is a rare side effect caused by the administration of adenosine.
Are you saying that the patient sneezed after you administered the adenosine?
Sneezing in some rare cases can cause a vasovagal response which could cause syncope.
From a brief review of the literature, Sneezing is not typically a precursor to a block.
Kind regards,
Jeff
Rainer says
What about intravenous ATP infusions over prolonged time? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2039853/
When given too quickly, will they lead to cardiac arrest invariably? At which rate will they lead to cardiac arrest?
Jeff with admin. says
The study referenced has nothing to do with adenosine used within the framework of ACLS. Adenosine and its use within ACLS is limited to very rapid IV push of 6 mg and 12 mg doses. The rapid IV push of adenosine does cause a temporary (arrest) cessation of the electrical impulse of the heart. Adenosine is metabolized very rapidly by every cell in the body. For adenosine to cause arrest is must be a very rapid IV bolus and the dose would have to be extremely high. An infusion is not likely to cause cardiac arrest or even significant symptoms as the study suggests.
Kind regards,
Jeff
Kimberly says
Why can’t you use more than 12mg of adenosine on a patient that’s in STV? Is it something that might damages the heart later in life, or just your body won’t respond to it anymore because its already being metobized, so it’s no longer a shock to the body?
Jeff with admin. says
Other than in the AHA material, 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.
Adenosine does not build up in the system and is metabolized very rapidly by every cell in the body.
Kind regards,
Jeff
Shahram Bayanati says
Does Adenosine use in polymorphic SVT as well?
Jeff with admin. says
I have not ever heard of polymorphic SVT??
Do you mean polymorphic VT? If this is what you mean then the answer would be no you would not use adenosine for polymorphic VT because the rate is not regular.
SVT is typically caused by an accessory pathway in the heart and will have a regular rate that is generated by the ventricles. If you see an SVT like rhythm that is irregular, you should assume atrial fibrillation and adenosine is contraindicated for atrial fibrillation.
Studies in the literature report serious rhythm degeneration and even death when adenosine has been inadvertently given to patients with either atrial fibrillation or atrial flutter.
Ref:
Mallet ML. Proarrhythmic effects of adenosine: A review of the literature. Emerg Med J. 2004;21(4): 408–410.
Exner DV, Muzyka T, & Gillis AM. Proarrhythmia in patients with the Wolff-Parkinson-White syndrome after standard doses of intravenous adenosine. Ann Int Med. 1995;122(5):351–352.
12. Haynes BE. Two deaths after prehospital use of adenosine. J Emerg Med. 2001;21(2):151–154.
Shah CP, Gupta AK, Thakur RK, et al. Adenosine-induced ventricular fibrillation. Indian Heart Journal, 2001;53(2):208–210.
Kind regards,
Jeff
Liz says
No such thing as polymorphic SVT. Very important to know your cardiac rhythms if thinking about giving a medication affecting the heart!!!
Linds says
Shaming someone for asking questions is a bad way to ensure they continue to ask them. Especially when they’re critical questions about the heart. But I’m glad you’re talking your responsibility to educate this person so seriously, hopefully you haven’t done irreparable damage. Because the next time they’re unsure about something they might.
Dr.hasan says
Please remember that we have all been in the same shoes initially…a person is a learner till death..there are better ways to address and be contributory to someone’s knowledge