Actually, Humalog and Novalog can be given IV, but they cost more, & offer no advantage over regular insulin.
Just remember that IV insulin has a very short half-life. There's no point in giving an IV bolus of insulin unless you are going to start a drip within 30 minutes. The ER docs are famous for doing this and all it does is lower the pt's BG for a few minutes. In fact, to quote a well respected UofMiami endocrinologist, "the only place for regular insulin in a hospital is in an insulin drip." We're still trying to abolish use of the "regular insulin sliding scale" (RISS)
Like I tell all of my students and new RN's LOOK IT UP ! Never take what anyone tells you as fact. Besides if you look it up your more likley to remember the facts. If you find it in a med book , if you go to court you can say ....I found it in _____. But if you go to court and say, well the other nurse told me....... You'll look like a fool.