labetalol contraindicated in cocaine users?

[soxman]

I've read that labetalol is contraindicated to treat HTN in cocaine users or any sympathomimetic drug, but I cant seem to get the reasoning well in my head. Could anyone enlighten me on this? Thanks!

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[tkim]

http://emedicine.medscape.com/article/813959-treatment#aw2aab6b6b4

"However, labetalol, a combined alpha- and beta-blocking agent, has an alpha-to-beta blockade ratio of 1:7. Therefore, it may not provide enough protection for cocaine-toxic patients from (relatively) unopposed alpha stimulation. Its risk of exacerbating myocardial ischemia parallels the risk of beta-blockers. Labetalol also increased seizures and mortality in animal models; therefore, its use cannot be promoted."

 

[cbrons]

I actually thought labetalol WAS the only BB you could use for cocaine overdose.

http://www.ncbi.nlm.nih.gov/pubmed/8124849

SUMMARY:

Unlike "pure" beta blockers, labetalol maintains cardiac output, reduces total peripheral resistance, and does not decrease peripheral blood flow. It has been used to treat hypertension of all degrees of severity and may be especially useful in black patients, elderly patients, patients with renal disease, and in pregnancy. It can be used in conditions that produce catecholamine crises, such as pheochromocytoma, clonidine withdrawal, and cocaine overdose. Its hemodynamic profile is attractive for use in myocardial ischemia. The parenteral form is useful in situations where blood pressure must be lowered quickly. The major side effect is orthostatic hypotension, and hepatotoxicity has been reported.
CONCLUSIONS:

Labetalol has several advantages over pure beta-blocking drugs and offers an alternative in managing hypertension that is difficult to control.


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Can a pharmacist clarify this?

 

[gasflea]

not a pharmacist... but i think the IM world is starting to say that beta blockade in cocaine abusing patients may not be so bad... There is debate, but some experts believe that in the absence of definitive evidence of harm in humans, beta blockers should be used if there is a class I indication for beta blockade. Example: CHFer who uses cocaine... needs to be on an appropriate beta blocker.

Not sure how this fits into the anesthesia world though, would love to hear some thoughts

Circulation.
2008; 117: 1897-1907 AHA Scientific Statement
Management of Cocaine-Associated Chest Pain and Myocardial Infarction

Arch Intern Med. 2010 Nov 8;170(20):1859-60; author reply 1860.
Beta-blockers and cocaine: still a bad idea.
Gupta AK, Greller HA, Hoffman RS.

Arch Intern Med. 2010 May 24;170(10):874-9.
Beta-blockers for chest pain associated with recent cocaine use.
Rangel C, Shu RG, Lazar LD, Vittinghoff E, Hsue PY, Marcus GM.

 

[gasflea]

if i had to acutely treat htn emergency, I might try a benzo

 

[Gern Blansten]

http://emedicine.medscape.com/article/813959-treatment#aw2aab6b6b4

"However, labetalol, a combined alpha- and beta-blocking agent, has an alpha-to-beta blockade ratio of 1:7. Therefore, it may not provide enough protection for cocaine-toxic patients from (relatively) unopposed alpha stimulation. Its risk of exacerbating myocardial ischemia parallels the risk of beta-blockers. Labetalol also increased seizures and mortality in animal models; therefore, its use cannot be promoted."

The above is also my understanding.

 

[soxman]

thanks for the replies, guys! I thought that labetalol had a blockade ration of 1:3 (alpha:beta) but never knew that it was actually 1:7!

 

[partydoc]

thanks for the replies, guys! I thought that labetalol had a blockade ration of 1:3 (alpha:beta) but never knew that it was actually 1:7!

1:7 iv, 1:3 po

 

[pgg]

I would think that most of these patients who are admitted for hypertensive crisis, regardless of cause, are going to a monitored bed and will probably get a-lines for continuous BP monitoring. In that case I doubt it matters what agents you use, so long as you do it carefully. Ie nothing wrong with some beta blocker, so long as you throw in something else to handle the alpha.

(Ordering a drug to be given by a nurse, and checking back in 10 or 15 minutes, in the usual non-anesthesiologist intensivist / ED style isn't what I mean here.)

 

[periopdoc]

Why not just give phentolamine plus Nipride or nitroglycerin?

- pod

 

[BLADEMDA]

Why not just give phentolamine plus Nipride or nitroglycerin?

- pod

Old school. It works well.


http://guidelines.gov/content.aspx?id=12951 (easy and quick summary)

 

[BADMD]

The reality is that no one really knows the answer.

None of the studies are all that good. Labetolol probably won't induce a hypertensive crisis, but it isn't that good at fixing the vasospasm associated with cocaine chest pain. My first line for acute intoxication is large dose benzodiazepine therapy, followed by nitroglycerin.

 

[Gern Blansten]

The reality is that no one really knows the answer.

None of the studies are all that good. Labetolol probably won't induce a hypertensive crisis, but it isn't that good at fixing the vasospasm associated with cocaine chest pain. My first line for acute intoxication is large dose benzodiazepine therapy, followed by nitroglycerin.

Years ago, a colleague gave labetalol to a patient that had an untreated pheo and had a HTN crisis just as described. Not saying it always happens, but it can happen.

 

[Planktonmd]

If the cocaine abuser is having an acute hypertensive/ tachycardic epissode I would start Nitroglycerine first then give Labetalol.

 

[proman]

If the cocaine abuser is having an acute hypertensive/ tachycardic epissode I would start Nitroglycerine first then give Labetalol.

.My first line for acute intoxication is large dose benzodiazepine therapy, followed by nitroglycerin.

Like our local toxicologist, BADMD, said first line treatment for acute hypertensive crisis from cocaine is benzodiazepine. The crisis is from CNS hyperactivity. Treat that first.

 

[Planktonmd]

Like our local toxicologist, BADMD, said first line treatment for acute hypertensive crisis from cocaine is benzodiazepine. The crisis is from CNS hyperactivity. Treat that first.

Makes sense

 

[Bostonredsox]

if i had to acutely treat htn emergency, I might try a benzo

This is my answer. 5 of Valium and a nitro drip. Although I am growing quite fond of nicardapene In my non HD or AKI htn emergencies. Actually discussed this with cardio attending other day on rounds, so long as they're not cocaine + and having an actual MI whether its vasospasm or true occlusion infarct, BBs are not truly contraindicated. But, as there are so many other options out there, why use the BB? Valium/Ativan + nitro/nipride works exceedingly well. Though I spose you can BB them and add phentolamine, never used it though personally.