Medical Editor: John P. Cunha, DO, FACOEP Last updated on RxList: 9/13/2021
Inapsine Side Effects Center

What Is Inapsine?

Inapsine (droperidol) is a sedative, tranquilizer, and anti-nausea medication used to reduce nausea and vomiting caused by surgery or other medical procedures. Inapsine is available in generic form.

What Are Side Effects of Inapsine?

Common side effects of Inapsine include:

  • drowsiness,
  • dizziness, or
  • feeling restless or anxious

Dosage for Inapsine

The maximum recommended adult initial dose of Inapsine is 2.5 mg IM (intramuscular) or slow IV (intravenous). For children two to 12 years of age, the maximum recommended initial dose is 0.1 mg/kg, taking into account the patient's age and other clinical factors.

What Drugs, Substances, or Supplements Interact with Inapsine?

Inapsine may interact with arsenic trioxide, diuretics (water pills), laxatives, drugs to treat psychiatric disorders, anti-malaria medication, heart or blood pressure medications, heart rhythm medication, drugs to treat high blood pressure or a prostate disorder, narcotics, or antibiotics, Tell your doctor all medications you use.

Inapsine During Pregnancy or Breastfeeding

During pregnancy, Inapsine should be taken only if prescribed. It is unknown if this drug passes into breast milk or if it could harm a nursing baby. Consult your doctor before breastfeeding.

Additional Information

Our Inapsine (droperidol) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Inapsine Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Tell your caregivers right away if you have:

  • fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out);
  • slow heart rate, weak pulse, fainting, slow breathing (breathing may stop);
  • confusion, hallucinations;
  • bronchospasm (wheezing, chest tightness, trouble breathing);
  • twitching or uncontrollable movements of your eyes, tongue, jaw, or neck; or
  • severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors.

Serious side effects may be more likely in older adults.

Common side effects include:

  • fast heart rate;
  • drowsiness, dizziness; or
  • feeling restless, anxious, or uneasy.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Inapsine (Droperidol)


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Inapsine Professional Information


QT interval prolongation, torsade de pointes, cardiac arrest, and ventricular tachycardia have been reported in patients treated with INAPSINE. Some of these cases were associated with death. Some cases occurred in patients with no known risk factors, and some were associated with droperidol doses at or below recommended doses.

Physicians should be alert to palpitations, syncope, or other symptoms suggestive of episodes of irregular cardiac rhythm in patients taking INAPSINE and promptly evaluate such cases (see WARNINGS, Effects On Cardiac Conduction).

The most common somatic adverse reactions reported to occur with INAPSINE (droperidol) are mild to moderate hypotension and tachycardia, but these effects usually subside without treatment. If hypotension occurs and is severe or persists, the possibility of hypovolemia should be considered and managed with appropriate parenteral fluid therapy.

The most common behavioral adverse effects of INAPSINE (droperidol) include dysphoria, postoperative drowsiness, restlessness, hyperactivity and anxiety, which can either be the result of an inadequate dosage (lack of adequate treatment effect) or of an adverse drug reaction (part of the symptom complex of akathisia).

Care should be taken to search for extrapyramidal signs and symptoms (dystonia, akathisia, oculogyric crisis) to differentiate these different clinical conditions. When extrapyramidal symptoms are the cause, they can usually be controlled with anticholinergic agents.

Postoperative hallucinatory episodes (sometimes associated with transient periods of mental depression) have also been reported.

Other less common reported adverse reactions include anaphylaxis, dizziness, chills and/or shivering, laryngospasm, and bronchospasm.

Elevated blood pressure, with or without pre-existing hypertension, has been reported following administration of INAPSINE combined with SUBLIMAZE (fentanyl citrate) or other parenteral analgesics. This might be due to unexplained alterations in sympathetic activity following large doses: however, it is also frequently attributed to anesthetic or surgical stimulation during light anesthesia.


Potentially Arrhythmogenic Agents

Any drug known to have the potential to prolong the QT interval should not be used together with INAPSINE. Possible pharmacodynamic interactions can occur between INAPSINE and potentially arrhythmogenic agents such as class I or III antiarrhythmics, antihistamines that prolong the QT interval, antimalarials, calcium channel blockers, neuroleptics that prolong the QT interval, and antidepressants.

Caution should be used when patients are taking concomitant drugs known to induce hypokalemia or hypomagnesemia as they may precipitate QT prolongation and interact with INAPSINE. These would include diuretics, laxatives and supraphysiological use of steroid hormones with mineralocorticoid potential.

CNS Depressant Drugs

Other CNS depressant drugs (e.g., barbiturates, tranquilizers, opioids and general anesthetics) have additive or potentiating effects with INAPSINE. Following the administration of INAPSINE, the dose of other CNS depressant drugs should be reduced.

Read the entire FDA prescribing information for Inapsine (Droperidol)

© Inapsine Patient Information is supplied by Cerner Multum, Inc. and Inapsine Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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