For pulseless VT/VF-defibrillation first- remember the first three successive shocks first! If still pulseless either epi or vasopressin per protocol and consider antiarrhythmics- continue with shock/drug etc...amiodarone is something that is being given along with everything else. I know you didn't specificially ask about this part but I figured I would say it so those that are newer to the code thing don't forget about that part. Amiodarone is not the first line drug for a code (although it is the often the first line antiarrhythmic recommended.)
Amiodarone has mulitple effects on the sodium, potassium, and calcium channels. Like papawjohn said, it does all kinds of things! It is kind of like the fire department putting out a big fire. So after you shock, shock, shock, give some epi, do some CPR- patient is still if VT or VF- somebody is preparing that syringe of Amiodarone. Drug/Shock etc is continued and Amiodarone 300mg IV push can be given as treatment for cardiac arrest due to shock resistant VF or pulseless VT. Dilute the drug with 20-30 cc of D5W. If VF/Vt recurs you can consider a second dose of 150 mg IV. The max cumulative dose is 2.2g over 24 hours.
If after you receive a perfusing rhythm- an IV continuous antiarrhythmic should be considered. A rapid infusion of 150 mg over 10 minutes should be bolused if the patient reverts back to pulseless VT/VF, then a continuous infusion of 360 mg (1 mg/min) over 6 hours (33.33 cc/hr in you are mixing 900mg in 500d5) then a maintenence infusion of 540 mg over the next 18 hours (0.5 mg/min or 16.6 cc/hr). Of course you can consider lidocaine or procainamide as well...
That being said- I almost never see amiodarone given IVP...it seems we shock most people out of pulseless VT/VF with one of the first three shocks at which time we administer either 300 mg or 150 mg mixed in 100cc and run it in over 10 minutes. Then we start a drip as I outlined in the above paragraph. Our docs all start amiodarone if there has been issues with Vt or VF.
Our docs start amiodarone alot. It is a nice drug because you can use it on both impaired and noraml hearts. OUr docs will often start if for freqent pvcs or pacs or little runs of either (depending on the patient/lab values/other issues examined) we also frequently use it for stable VT, pulseless VT, VF, AFIB (both rate control and rhythm conversion).
I hardly ever see lido used and procainamide even less (in fact, I think that I have only used this once- and the patient was already on amio/lido etc... she didn't do so well).