droperidol (Inapsine)

Introduction

Tradename: Inapsine.

Indications

• symptomatic treatment of nausea & vomiting
• adjunct to analgesia

Contraindications

• NOT to be used for sedation/anxiolysis in intensive care patients
• avoid in elderly patients

pregnancy category = c

safety in lactation = ?

Dosage

• tranquilization & reduction of operative nausea
  • 2.5 to 10 mg IV/IM
• adjunct to analgesia with fentanyl
  • 1.25 to 5.0 mg IV/IM
• chemotherapy-induced nausea/vomiting
  • haloperidol is 1st line agent
  • 2.5 mg IV/IM every 3-6 hours PRN.
• treatment of vomiting in the emergency department

Pharmacokinetics

• onset of action is 3-10 minutes, sometimes longer
  • when given IM, droperidol has a more rapid onset of action & a shorter 1/2life than haloperidol
• tranquility effect lasts 2-4 hours
• drowsiness & altered consciousness may last 12 hours
• readily crosses blood-brain barrier
• metabolized by liver
• excreted in urine & feces

elimination via liver

Monitor

blood pressure, EKG

Adverse effects

• common (> 10%)
  • drowsiness, hypotension (mild to moderate), tachycardia
• less common (1-10%)
  • extrapyramidal (dystonic) reactions, respiratory depression, hypertension
• uncommon (< 1%)
  • dizziness, chills, shivering, laryngospasm, bronchospasm, hallucinations
• other
  • restlessness
  • facial sweating
  • may cause delirium in elderly patients
  • prolongation of QT interval -> torsades de pointes

• drug adverse effects of dopaminergic receptor antagonists
• drug adverse effects of antihypertensive agents

Drug interactions

• lowers seizure threshold when used concurrently with analeptics
• increased CNS depression when used concurrently with CNS depressants
• antagonizes dopaminergic activity of anti-Parkinson agents
• in combination with alpha-methyldopa may cause dementia
• reverses pressor effects of epinephrine
• fentanyl or other analgesics in combination may exacerbate hypertension
• avoid use with other agents that prolong the QT interval

• drug interaction(s) of NSAIDs & antihypertensives

Mechanism of action

• butyrophenone, similar to haloperidol
• strong central dopamineric (D2-selective) antagonism
  • mesolimbic system
  • frontal cortex
  • chemoreceptor trigger zone (CTZ)
• inhibits sympathetic postganglionic alpha-receptors, causing vasodilation

More general terms

• butyrophenone
• dopaminergic receptor antagonist
• anti-emetic

Component of

• droperidol/fentanyl
• intravenous anti-emetic combination

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=3168