half-life question

[blee1]

i just started in a CTICU and ive gotten questions about half-lifes of drugs (eg. epi, dop, dob, mil, etc.) by some of my preceptors. why is it that some make it a big deal to know? isnt more important to know when a drugs peak affects will occur and their duration of action? what am i missing here??

[jmgrn65, RN]

becasue in critical situations it is even more important to know how long a drug will be in the system.

[Diary/Dairy, RN]

Better to know how long they are going to be in the system before you have to know.....

[longroadahead]

The majority of those drugs are going to start working rapidly - what you really want to know is, once those drugs are up and hanging or once you've made a change in the drugs, how long is it going to take for the drug to wear off if the patient doesn't tolerate the change.

For instance, let's say you've got a patient on a beta blocker drip for rate control with atrial flutter and all of a sudden you're pressure is in the toilet (even though you didn't change a thing on the beta blocker or any other medication). You're going to want to know exactly how long the effects of that beta blocker drip are going to last (once you've turned it down or off) and when you should start to see an effect of the drug wearing off (i.e., the pressure coming back up) and if you don't see any effect in the blood pressure after the drug should be starting to wear off what are you going to want to do next?

You need to know the half-life. Same thing if you're weaning off epi - you're going to want to know the half-life in order to know when to shoot some cardiac numbers and determine if the heart is working adequately enough with the change in the epi.

It's all about the half-life.