THERAPEUTICS

Brands

• Inapsine

Generic?

• Yes

Class

• Antiemetic

Commonly Prescribed for

(FDA approved in bold)

• Antiemetic for nausea and vomiting related to surgical and diagnostic procedures

• Migraine (acute)

• Chemotherapy-induced nausea and vomiting

How the Drug Works

• Antidopaminergic, with mild α1 adrenergic blockade and sedative effects

How Long Until It Works

• Migraine, nausea in less than 10 minutes

If It Works

• Use at lowest required dose

• Monitor QTc interval, potassium and magnesium level

If It Doesn't Work

• Change to another agent

Best Augmenting Combos for Partial Response or Treatment-Resistance

• For migraine, can be used with dihydroergotamine or NSAIDs

Tests

• Obtain ECG to monitor QTc

ADVERSE EFFECTS (AEs)

How the Drug Causes AEs

• Hypotension and dizziness are related to α-blockade, and abnormal movement AEs are related to dopamine blocking effects

Notable AEs

• Drowsiness, hypotension, tachycardia, chills

• Dystonia, akathisia, restlessness, anxiety, state of mental detachment

• Less common: elevated blood pressure, apnea, muscular rigidity

Life-Threatening or Dangerous AEs

• QTc prolongation and torsade de pointes have been reported, especially with higher doses

Weight Gain

• Unusual

Sedation

• Common

What to Do About AEs

• Lowering dose or changing to another antiemetic improves most AEs

• Use with caution in patients if QTc is above 450 (females) or 440 (males). Lower dose or change to another agent. Do not administer droperidol for QTc greater than 500

• For patients on daily IV therapy, continue to monitor with daily ECG, especially as dose increases

Best Augmenting Agents to Reduce AEs

• Give fluids to avoid hypotension and dizziness

• Give anticholinergics (diphenhydramine or benztropine) for extrapyramidal reactions

DOSING AND USE

Usual Dosage Range

• 0.625–2.5mg every 6–8 hours

Dosage Forms

• Injection: 2.5mg/mL