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a drug of the butyrophenone series, used for its antianxiety, sedative, and antiemetic effects as a premedication prior to surgery and during induction and maintenance of anesthesia, as a postanesthesia antiemetic, and to produce conscious sedation; administered intravenously or intramuscularly. A combination of droperidol and fentanyl citrate is administered intramuscularly to produce neuroleptanalgesia.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.



Pharmacologic class: Butyrophenone

Therapeutic class: General anesthetic, antiemetic

Pregnancy risk category C

FDA Box Warning

• QT prolongation and torsades de pointes may occur at or below recommended doses, even in patients with no known risk factors. (Risk factors for prolonged QT syndrome include heart failure, bradycardia, cardiac hypertrophy, hypokalemia, hypomagnesemia, age older than 65, alcohol abuse, and use of diuretics, drugs that prolong the QT interval, benzodiazepines, volatile anesthetics, or I.V. opioids.) Some cases have been fatal. Reserve drug for patients with refractory disease. Use with extreme caution in patients at risk for prolonged QT interval.

• Drug is contraindicated in patients with known or suspected QT prolongation.


Produces marked sedation by directly blocking subcortical receptors. Produces antiemetic effect by blocking CNS receptors in chemoreceptor trigger zone.


Injection: 2.5 mg/ml in 1-ml, 2-ml, and 5-ml ampules and in 2-ml, 5-ml, and 10-ml vials

Indications and dosages

Perioperative nausea and vomiting

Adults: Initially, 2.5 mg I.M. or I.V. Additional doses of 1.25 mg may be given. Dosages are highly individualized according to patient's age, weight, physical status, and underlying pathologic condition.

Children ages 2 to 12: Initially, 0.1 mg/kg I.M. or I.V. Additional doses up to a total of 2.5 mg may be given. Dosages are highly individualized according to patient's age, weight, physical status, and underlying clinical condition.

Dosage adjustment

• Elderly or debilitated patients

• High-risk patients (such as patients over age 65 and those with heart failure, alcohol abuse, or other factors that predispose to prolonged QT interval)

• Patients who have received other CNS depressants (such as analgesics or anesthetics)


• Hypersensitivity to drug

• Known or suspected QT-interval prolongation (more than 440 millisec in males or 450 millisec in females)


Use cautiously in:

• severe cardiac or renal disease, diabetes mellitus, respiratory insufficiency, prostatic hypertrophy, angle-closure glaucoma, CNS depression, CNS tumors, intestinal obstruction, bone marrow depression

• elderly patients

• pregnant or breastfeeding patients

• children younger than age 2.


• Know that drug is indicated to ease perioperative nausea and vomiting only in patients who don't respond adequately to other treatment.

• Be aware that drug doesn't need to be diluted for I.V. or I.M. use.

• Give by slow I.V. injection, or inject I.M. into large muscle.

Adverse reactions

CNS: weakness, dysarthria, dysphonia, dizziness, extrapyramidal reactions, headache, postoperative hallucinatory episodes with transient depression, tremor, irritability, paresthesia, aggression, vertigo, ataxia, loss of consciousness, seizures, neuroleptic malignant syndrome

CV: chest pain, hypertension, hypotension, vasodilation, arrhythmias, atrial fibrillation

EENT: cataracts, blurred vision, eye irritation, sore throat

GI: nausea, vomiting, diarrhea, abdominal cramps, bloating, epigastric pain, fecal incontinence, increased salivation, dysphagia

GU: urinary frequency, increased libido

Hepatic: cholestatic jaundice

Metabolic: dehydration

Musculoskeletal: muscle cramps, arthritis, bone fractures

Respiratory: bronchitis, dyspnea

Skin: bruising, rash, urticaria, facial sweating, diaphoresis, pruritus, flushing

Other: toothache, weight loss, hot flashes, influenza, chills


Drug-drug. Antihypertensives, nitrates: additive hypertension

CNS depressants (including antidepressants, antihistamines, opioids): additive CNS depression

Drugs that induce hypokalemia or hypomagnesemia (such as diuretics and laxatives and supraphysiologic use of steroid hormones with mineralocorticoid activity): possible precipitation, QT interval prolongation

Drugs that prolong QTc interval (such as antidepressants, class I or III antiarrhythmics, antimalarials, calcium channel blockers, some antihistamines, some neuroleptics): increased risk of conduction abnormalities

Drug-herbs. Chamomile, hops, kava, skullcap, valerian: increased CNS depression

Drug-behaviors. Alcohol use: additive CNS depression

Patient monitoring

Monitor QT interval; report prolongation. Also watch for torsades de pointes.

Know that drug may cause sudden death at high doses (above 25 mg) in patients at risk for arrhythmias.

Monitor for signs and symptoms of neuroleptic malignant syndrome, such as hyperthermia, severe extrapyramidal symptoms, altered mental status, stupor, coma, hypertension, tachycardia, pallor, or diaphoresis. (However, this syndrome is rare.)

• Assess vital signs frequently. Stay alert for orthostatic hypotension and tachycardia. Keep I.V. fluids and vasopressors on hand to treat pronounced hypotension.

Don't place hypotensive patient in Trendelenburg position because this may deepen anesthesia, precipitating respiratory arrest.

• Avoid abrupt position changes.

• Observe for signs and symptoms of respiratory compromise if drug is used concurrently with narcotics.

Patient teaching

• Advise patient not to drink alcohol or take CNS depressants for 24 hours after receiving drug.

• Tell patient drug may cause extreme drowsiness for several days after administration.

• Caution patient not to drive or perform other activities requiring mental alertness.

• Instruct patient to change positions slowly.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, herbs, and behaviors mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


A butyrophenone antipsychotic drug that causes emotional quietening and a state of mental detachment. It is sometimes used as a premedication before surgery.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
The most severe form of nausea, hyperemesis gravidarum, occurs in less than 1% of pregnancies and requires hospitalization and intravenous antiemetics, such as droperidol (Inapsine), prochlorperazine, and ondansetron.
* Finally, droperidol (Inapsine) appears to be a particularly effective agent for migraine headaches of any duration, but especially those that are prolonged.
Hyperemesis gravidarum, requires intravenous antiemetics, such as droperidol (Inapsine), prochlorperazine, and ondansetron.
He also expects that it will help fill the "substantial void" created by the reduced use of intramuscular and intravenous droperidol (Inapsine) for acute agitation.
Benztropine [bull] Cogentin Clomipramine [bull] Anafranil Diphenhydramine [bull] Benadryl Droperidol [bull] Inapsine Haloperidol [bull] Haldol Ketamine [bull] Ketalar Nitroprusside [bull] Nitropress
Diazepam (Valium), pentobarbital, betamethasone, mannitol, lorazepam (Ativan), baclofen (Lioresal), phenytoin (Dilantin), and droperidol (Inapsine) are additional drugs identified within the literature with varied success (Baguley et al.; Boeve et al.; Horntagl et al.; Pranzatelli et al.; Rossitich & Bullard; Strum; Thorley, Wertsch, & Klingbeil).
In December 2001, the Food and Drug Administration placed a black box warning on droperidol (Inapsine) because of concerns over QT prolongation and torsades de pointes.
These other causes include kidney failure, diabetes, nerve damage and certain medications including antiseizure drugs such as phenytoin (Dilantin) or droperidol (Inapsine); antinausea drugs such as prochlorperazine (Compazine) or metoclopramide (Reglan); antipsychotic drugs such as haloperidol (Haldol); and most antidepressant medications, including widely prescribed ones such as fluoxetine (Prozac), paroxetine (Paxil) and sertraline (Zoloft).
Neuroleptics frequently used are oral or IM haloperidol (Haldol) 2-10 mg and IM droperidol (Inapsine) 1-2 mg.