Dopamine and Haldol

 Q:  Haloperidol ______________ the vasodilatory effect of low dose Dopamine (at 1 to 2 mcg/kg/minute)? (select one) 

 A) increases 

B) decreases 

 

Answer: B

The objective of the above question is to highlight the drug interactions which frequently get forgotten under the complicated need for polypharmacy in ICU. The response to Dopamine is dose-dependent At a lower dose of 1 to 2 mcg/kg/minute, it has a vasodilatory effect via dopamine-1 receptors in the renal, mesenteric, cerebral, and coronary beds. Description of all of the effects of Dopamine is beyond the scope of this website.  

Haloperidol is still a common and reflexly ordered drug in ICU. It blunts the vasodilatory effect of Dopamine. The mechanism of action of Haloperidol is by inhibiting dopamine. It is a Dopamine antagonist.

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#cardiology

#psychiatry

References:

1. Dasta JF, Kirby MG. Pharmacology and therapeutic use of low-dose dopamine. Pharmacotherapy 1986; 6:304.

2. Fox CA, Mansour A, Watson SJ Jr. The effects of haloperidol on dopamine receptor gene expression. Exp Neurol. 1994 Dec;130(2):288-303. doi: 10.1006/exnr.1994.1207. PMID: 7867758.