[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Dopamine-antagonist antiemetics and prokinetics](https://durgical.com/en/pharmacology/classes/dopamine-antagonist-antiemetics-and-prokinetics/) › Droperidol # Droperidol ## Dopamine-antagonist antiemetics and prokinetics? Dopamine-antagonist antiemetics and prokinetics A butyrophenone dopamine blocker given by injection to prevent nausea and vomiting around surgery. It can prolong the QT interval. Updated Nov 1, 2026 ## Quick facts **Group** [Dopamine-antagonist antiemetics and prokinetics](https://durgical.com/en/pharmacology/classes/dopamine-antagonist-antiemetics-and-prokinetics/) **Target** Dopamine D2 receptor (chemoreceptor trigger zone) **Used for** Prevention and treatment of nausea **Key effects** Mild to moderate low blood pressure · Restlessness **Monitor** Blood pressure and heart rate **ATC** N05AD08 No doses: the clinician sets them by the current guideline. On this page - The basics Mechanism of action - Indications - Adverse effects - Pharmacokinetics - Memory aid - Safety Contraindications - Key interactions - What is monitored - Administration and safety - Pregnancy and breastfeeding - Nursing care - Study Test yourself - Connections Connections ## Mechanism of action ◎**Dopamine D2 receptor (chemoreceptor trigger zone)**Droperidol ⓘ The figure shows haloperidol, the butyrophenone closest to droperidol, bound to the human D2 receptor. **Target in 3D:** Dopamine D2 receptor (chemoreceptor trigger zone). PDB structure 6LUQ (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/6LUQ) · Drag to rotate · pinch to zoom Droperidol is a butyrophenone neuroleptic. It blocks dopamine D2 receptors in the chemoreceptor trigger zone, which lowers nausea and vomiting during and after surgery and diagnostic procedures. It also sedates, causes mild alpha-adrenergic blockade with vasodilation and low blood pressure, and potentiates other CNS depressants. Like other butyrophenones it can prolong the QT interval and trigger torsade de pointes. - Droperidol blocks D2 receptors in the trigger zone - Less nausea and vomiting around surgery - Sedation and mild alpha-blockade (low blood pressure) - Delayed repolarisation can prolong QT ## Indications - Prevention and treatment of nausea and vomiting with surgical and diagnostic procedures, when other treatments fail or are unsuitable ## Adverse effects ### Common - Mild to moderate low blood pressure and fast heart rate - Drowsiness after surgery - Restlessness, anxiety, dysphoria (often akathisia) - Dizziness, chills, shivering ### Serious (rare, important) - QT prolongation, torsade de pointes, ventricular arrhythmias, cardiac arrest (boxed warning) - Extrapyramidal reactions: dystonia, akathisia, oculogyric crisis - Neuroleptic malignant syndrome - Severe hypertension and tachycardia in phaeochromocytoma - Anaphylaxis, laryngospasm, bronchospasm (rare) ## Contraindications - Known or suspected QT prolongation, including congenital long QT syndrome - Hypersensitivity to droperidol - Extreme caution with bradycardia, heart disease, low potassium or magnesium, or other QT-prolonging drugs ## Key interactions **Other QT-prolonging drugs (class I and III antiarrhythmics, some antihistamines, antimalarials, antipsychotics, antidepressants)** Additive QT prolongation and torsade risk; not combined **Drugs that lower potassium or magnesium (diuretics, laxatives, mineralocorticoid steroids)** Electrolyte loss makes QT prolongation more likely **Opioids, benzodiazepines, barbiturates, general anaesthetics** Additive CNS depression; the doses of both are lowered **MAO inhibitors** Listed among risk factors for QT prolongation; extreme caution ## What is monitored - 12-lead ECG before the dose to exclude a prolonged QT - ECG monitoring for a few hours after the dose when risk is accepted - Blood pressure and heart rate - Potassium and magnesium - Sedation and extrapyramidal signs ## Administration and safety - For IV or IM use only. - Fluids and other measures to treat low blood pressure must be ready. - Lower starting doses are used in older, frail and high-risk patients. - Move and position the patient carefully because of orthostatic hypotension. - Look-alike risk with other butyrophenones (haloperidol); the name is checked. ## Pregnancy and breastfeeding There are no adequate studies in pregnant women; use in labour and delivery is not recommended. ## Nursing care - Confirm a 12-lead ECG and normal QT before giving it. - Review the medication list for other QT-prolonging drugs and check potassium and magnesium. - Watch for palpitations, fainting, low blood pressure and over-sedation after the dose. - Look for restlessness, dystonia or eye-rolling (extrapyramidal reactions). - Report fever, rigidity or confusion at once (neuroleptic malignant syndrome). ## Pharmacokinetics **Metabolism** Liver and kidney function matter for its metabolism and excretion; caution in their impairment **Half-life** Sedation usually lasts a few hours; reduced alertness can last up to about half a day **Onset and duration** Acts within minutes of an IV or IM dose; peak effect may take up to about half an hour ## Memory aid «Drop the nausea, watch the QT»: an ECG before droperidol, every time. ## Test yourself Think of the answer, then tap the question to see it. ## Which ECG check is required before droperidol? A 12-lead ECG to exclude a prolonged QT interval. ## Which receptor does droperidol block to prevent vomiting? The dopamine D2 receptor in the chemoreceptor trigger zone. ## A patient becomes restless and cannot sit still after droperidol. What is it? Probably akathisia, an extrapyramidal reaction. ## Which two electrolyte problems raise its QT risk? Low potassium and low magnesium. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/pharmacology/droperidol/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## Connections ## Related drugs 4 - [Haloperidol](https://durgical.com/en/pharmacology/haloperidol/) - [Metoclopramide](https://durgical.com/en/pharmacology/metoclopramide/) - [Prochlorperazine](https://durgical.com/en/pharmacology/prochlorperazine/) - [Ondansetron](https://durgical.com/en/pharmacology/ondansetron/) [← Back to the class: Dopamine-antagonist antiemetics and prokinetics](https://durgical.com/en/pharmacology/classes/dopamine-antagonist-antiemetics-and-prokinetics/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [DailyMed - DROPERIDOL injection, solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=147e033d-d997-4ef6-8bb5-a9ba372590b2) (DailyMed (U.S. National Library of Medicine), 2023); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=N05AD08) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [RCSB PDB - 6LUQ: Haloperidol bound D2 dopamine receptor structure inspired discovery of subtype selective ligands](https://www.rcsb.org/structure/6LUQ) (RCSB Protein Data Bank, 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/droperidol/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/droperidol/