New OB nurse with question about methergine and HTN crisis!

[Cpdrn]

Methergine can cause hypertensive crisis. How soon after administration for a post partum hemmorhage would one likely see a HTN crisis if one were to occur?

[SoldierNurse22, BSN, RN]

That really depends on the patient's underlying disease process(es) and the extent of the bleed.

Generally speaking, if you're giving methergine to a patient who is experiencing a hemorrhage and has contraindicating factors for the drug) such as preeclampsia, gestational hypertension, etc.,), a hypertensive crisis is going to be the least of your worries. Typically severe hypotension is more the concern in a hemorrhage.

However, to answer your question more directly, a drug given IM is generally going to start acting 10-20 minutes after administration, so that would be the earliest you'd see symptoms of hypertension. The half life is 3.39 hours, so if you are dealing with a hypertensive crisis, I would imagine the severity of the HTN would begin to fade at that point. If you've got a patient hemorrhaging, BP should be cycling at very close intervals (every 1 minute in my hospital), so you should be able to catch it pretty quickly.

[ArtF]

In this case the IM injection actually starts having an effect within 2-5 minutes of the injection. However a hypertensive crisis is much less likely when given IM. The risk is much worse for IV administration (also a high risk for CVA when given IV). The only time you should ever see it given IV though would be in a life or death situation. In any case where it would even be considered IV I would expect the patient to be monitored constantly while probably being taken to an OR if not already there.

[SoldierNurse22, BSN, RN]

My apologies, OP--onset time for methergine IM is 2-5 minutes, as stated by a PP. So if you were going to see symptoms of a hypertensive crisis, it would be much faster than what I indicated in my original post.