Amiodarone ========== þ Dosage: - v. fib: 300 mg IV - IV loading for other arrhythmias: + 150 mg over 10 minutes (15 mg/min): 3 cc (150 mg) in 100 cc D5W (1.5 mg/cc) + 360 mg over next 6 hours (1 mg/min): 18 cc (900 mg) in 250 cc D5W (1.8 mg/cc) - Maintenance: 0.5 mg/min þ If patient on amioadarone and now NPO: - half-life is 55 days, so if on it for 3-4 months can skip for up to 2 weeks. - if on 200-400 mg/day for less than 3-4 months, should receive equivalent dose (100-200 mg, bioavailability about 50%) slow bolus over 10-20 minutes. - if getting more than 360 mg/day, should be on continuous IV infusion [Mercy Pharmacy Newsletter, August 2002] þ Amiodrarone as primary treatment for v.fib. arrest Ian B. Leber, M.D. wrote: > Several days ago one of our Medics (City of Pittsburgh) brought this to > my attention. It appears that a trial was executed to determine the > utility of amiodarone in v-fib/tach arrest. I don't have the published > study, but I have been given a copy of the protocol that has been > enacted by the Richmond (Virginia) Ambulance Authority. This protocol > instructs their medics that when treating a pt in v-fib or > "hemodynamically unstable v-tach" who does not respond to three stacked > shocks, they are to administer epinephrine and 300mg of Amiodarone IV. > To my knowledge, this is the first system in the US to use > amiodarone as first line therapy in cardiac arrest. I am in the process > of locating the original study that shows improved outcome and I will, > of course, post the reference on the list. Does anyone out there have > any additional information on this topic? > > Ian The study was a prospective randomized double blinded study that demonstrated an improved return of spontaneous circulation for amiodarone in patients that presented in vfib. There was no difference between the two groups (amiodarone vs. lidocaine) for survival to hospital discharge. My conclusion: The study probably did not have the power to demonstrate a difference in survival to discharge. The author states it did not, but, the literature I saw did not state the power of the study. The literature was an abstract presented at the AHA, no manuscript published yet that I know of. The study shows no difference in survival to discharge. Amiodarone is a relatively expensive drug. I do not believe that there is any evidence to suggest that amiodarone should become a routine part of out-of-hospital protocol for cardiac arrest at this time. The evidence probably suggests that further study is warranted. Craig B. Key, MD, EMT-P Associate Medical Director, Houston Fire Department, EMS -------------------------- And, our hospital cost is $1200 per dose. Richard Medlin, Jr. Winston-Salem, NC 27103 dickrpm@ibm.net -------------------------- Probably charge instead of cost, because it's about 300 canadian $, which mean not much (and less from day to day) since few weeks.. Alain Vadeboncouer MD --------------------- There was a discussion of this topic on emed about three years ago, after the manufacturer began advertising in EM journals encouraging use in emergency patients with ventricular malignant dysrthythmias. I'm reposting a piece of this discussion below, as well as two more recent articles giving a broader overview of the topic (ref 1,2,3). I know the AHA has considered including amiodarone as a first line agent for v-fib and v-tach in future ACLS updates. James Li, M.D. Mt. Auburn Hospital Division of Emergency Medicine Harvard Medical School REFERENCES (1) Votey SR, Herbert ME. Intravenous amiodarone for treating acute life threatening arrhythmias. West J Med 1998 Mar;168(3):183. (2) ARREST (AMIODARONE IN THE OUT-OF-HOSPITAL RESUSCITATION OF REFRACTORY SUSTAINED VENTRICULAR TACHYARRHYTHMIAS) Clin Card 1998;21(1):52. (3) Desai AD, Chun S, Sung RJ. The role of intravenous amiodarone in the management of cardiac arrhythmias. Ann Intern Med 1997 Aug 15;127(4):294-303 PURPOSE: To review the electropharmacology, clinical applications, side effects, and hemodynamic profile of intravenous amiodarone. DATA SOURCES: The MEDLINE database was searched for English-language material, including reports of clinical trials and in vivo studies, review articles, and abstracts presented at national symposia, that was published between 1985 and 1996. Bibliographies of textbooks and articles were also examined. STUDY SELECTION: Studies that reported on the efficacy, toxicity, and hemodynamic profile of intravenous amiodarone and studies that examined the pharmacologic behavior of intravenous amiodarone in laboratory models were reviewed. DATA EXTRACTION: Study design and quality and relevant data on efficacy of suppression and treatment of arrhythmias with oral and intravenous amiodarone therapy, the reported mechanisms of antiarrhythmic effect, and hemodynamic changes seen with therapy were analyzed. DATA SYNTHESIS: Amiodarone is a unique antiarrhythmic agent that is now available in oral and intravenous forms in the United States. The use of intravenous amiodarone in the short-term treatment of life-threatening or hemodynamically unstable rhythm disturbances has generated much interest. Amiodarone has many electropharmacologic actions, some of which differ between the oral and intravenous forms. The wide clinical application of amiodarone includes treatment and prevention of supraventricular and ventricular arrhythmias and arrhythmias related to myocardial infarction. Intravenous amiodarone is effective for supraventricular and ventricular arrhythmias that are resistant to other antiarrhythmic agents. The effectiveness of intravenous amiodarone as short-term treatment also suggests that the drug has an important role in protocols of advanced cardiac life support. Intravenous amiodarone seems to have an overall favorable hemodynamic profile and does not produce many of the unwanted long-term side effects associated with oral therapy. CONCLUSION: Intravenous amiodarone shows much promise for the short-term treatment of unstable arrhythmias. Its favorable hemodynamic effects and minimal short-term side effects make it an attractive option in the management of cardiac arrhythmias. PREVIOUS DISCUSSION: On 11-24-95 Simon Brown wrote: >I think amiodarone would be useful only infrequently in prolonged (as >opposed to recurrent) ED cardiac arrest, because the vast majority of >patients that do not respond to defibrillation or pacing tend to snuff it >no matter what we do. >As regards recurrent VF/VT arrests (which I seem to be encountering very >rarely these days), I find that Oxygenation, Lignocaine, Bretyllium and >Magnesium do the trick 99% of the time. Next line? I would actually try >sotolol next, amiodarone last. Personal preference with little science! >As the ERC recommends, a lot of research is needed here. It will also >need to be multicentre, as the numbers will be hard to get. >Success with amiodarone after 45 minutes of cardiac arrest? I doubt it. >More like the patients had perfusing rhythms throughout most of the >reported arrests and amiodarone just happened to be the poison that was >tried on recurrent (as opposed to persistent) VT/VF. I know amiodarone is >a fantastic drug, but it does not bring people back from the dead, at >least as far as I am aware..... In the study from from the Annals of Internal Medicine 1989 (4), that I reviewed, all of the patients who repsonded to amiodarone did indeed have recurrent, as opposed to, incessant v-fib. All of them had brief periods of perfusing rhythms related to the use of conventional treatment prior to it's administration. Two case reports, however, descibed patients with unrelenting v-fib. Both were from the Br Med J. In one (1) (massive digoxin overdose) v-fib unresponsive to epi, lidocaine and countershock. Amiodarone was administered 50 minutes into the resusitation attempt and he was sucessfully defibrillated 10 minutes later. The second case (2) was a postoperative patient who went into v-fib unresponsive to lidocaine, disopyramide (! no wonder they couldn't convert him) and 15 (!) defibrillation attempts over a period of 75 minutes. Three minutes after administration of amiodarone he was sucessfully converted with 400 j. What is one to make of case reports like this? Probably very little. Unless it is that "Acts of God" do appear to happen and physician's sometimes take the credit for it. I recall the initial enthusiasm over the use of bretyllium when it first came out. There was talk about "chemical defibrillation". After more sober reflection (read controlled studies), no advantage in comparison to the use of lidocaine could be consistantly demonstrated. If amiodarone turns out to be only useful in cases where rythyms (perfusing or otherwise) are transiently restored please consider that this would not necessarily be a bad thing. After all, lidocaine increases the DEfibrillation thresh- hold at the same time that it increases the fibrillation thresh-hold. Thus it probably makes defibrillation MORE difficult than it otherwise would be. As the ERC summary stated "...adjunctive administration of lidocaine to patients in ventricular fibrillation may indeed hinder successful defibrillation" (3). H. Louzon MD (1) Massive Digoxin Overdose: Successful Treatment with Intravenous Amiodarone. Maheswaran et. al. Br Med J 1983 287:392-393 (2) Intravenous Amiodarone in Ventricular Fibrillation. Chapman et. al. Br Med J 1981 282:951-952 (3) Drug Treatment of Arrhythmias During Cardiopulmonary