ADMINISTRATION ROUTES:
IV, IM
ALTERNATIVE NAMES:
Droleptan
ICU INDICATIONS:
- Post-operative nausea and vomiting
- Acute severe agitation, hyperactivity or aggression in adults
PRESENTATION AND ADMINISTRATION:
2.5 mg in 1 mL clear colourless solution for injection. Administer undiluted by IV or IM route. Can dilute for administration over 1-2 minutes if required.
Compatible with the following IV fluids: 0.9% saline, 5% dextrose, Hartmann's.
Store at room temperature. Protect from light.
DOSAGE:
Nausea and vomiting:
IV:
0.5 - 1.25 mg PRN max QID
Acute severe agitation:
IM:
5 -10 mg. Max 20 mg in 24 hours
May take up to 30 mins for full effect.
IV:
2.5 – 5 mg, repeat 5 minutely if needed to max 20 mg
DOSAGE IN RENAL FAILURE OR HEPATIC IMPAIRMENT:
Max 0.625 mg PRN QID
DOSAGE IN PAEDIATRICS:
Post-operative nausea and vomiting:
20 – 50 mcg/kg (max 1.25 mg). Repeat PRN QID
CLINICAL PHARMACOLOGY:
Droperidol is a butyrophenone antipsychotic with antiemetic effect resulting from blockade of dopamine receptors in the chemoreceptor trigger zone. It also has mild alpha1-adrenergic blockade which can decrease peripheral vascular resistance.
When used in the setting of severe agitation, droperidol is equally effective by both IV & IM routes. The median time to effective sedation is 10 mins (IV) vs 20 mins (IM) for a 10 mg dose. In this setting, droperidol is associated with fewer adverse events and less need for repeat sedation when compared to midazolam. Droperidol should only be used in the short term for acute severe episodes.
CONTRAINDICATIONS:
- Hypersensitivity to droperidol
- Patients with Parkinson's disease
- Phaeochromocytoma
- Known QTc prolongation (males > 440 msec, females > 450 msec) including congenital long QT syndrome
WARNINGS:
QT prolongation / arrhythmia
Dose-dependent risk of QT prolongation and ventricular arrhythmias (such as torsades de pointes). Risk appears to be low with doses < 2.5 mg IV. Use with caution or avoid in patients with other risk factors for QT prolongation such as bradycardia, electrolyte disturbance (hypokalaemia/hypomagnesaemia), congestive cardiac failure, heavy alcohol consumption or concomitant use of other QT-prolonging drugs.
Neuroleptic malignant syndrome (NMS)
Droperidol has been associated with rare cases of NMS. Discontinue use immediately if hyperthermia occurs.
Parkinson's disease
Droperidol can precipitate or exacerbate symptoms of Parkinson's disease so should be avoided.
PRECAUTIONS:
General:
Patients at increased risk of cardiac arrhythmia should have baseline and serial ECG to assess QTc, and assessment of serum potassium and magnesium prior to receiving droperidol. Cardiac monitoring is recommended for patients receiving doses > 2.5 mg or at increased risk of QTc prolongation/arrhythmia.
Hepatic dysfunction:
Reduce dose as drug undergoes extensive hepatic metabolism (maximum 0.625 mg every 6 hours as required)
Pregnancy and lactation:
Droperidol is non-teratogenic in animals. There are occasional reports of neonates experiencing extrapyramidal or withdrawal symptoms after exposure to antipsychotics in third trimester. Limited data in breastfeeding.
Elderly:
Reduce dose. There is an increased risk of death in patients over 80 years of age when treated with antipsychotics for dementia-related psychosis.
IMPORTANT DRUG INTERACTIONS IN ICU:
Avoid combining droperidol with other drugs known to prolong the QT interval. If necessary, monitor QTc with ECG.
Potentiates the sedative action of benzodiazepines and other CNS depressants.
Inhibits the action of dopamine agonists (e.g. levodopa, bromocriptine).
ADVERSE REACTIONS
Cardiovascular:
QT prolongation, tachyarrhythmias including torsade de pointes and ventricular tachycardia / cardiac arrest, hypotension, hypertension (in patients with phaeochromocytoma)
Neurological:
Sedation, extrapyramidal symptoms (akathisia, dystonia, tardive dyskinesia, oculogyric crisis), hallucinations, NMS, anxiety, restlessness.
Gastrointestinal:
Decreased gastrointestinal motility due to anticholinergic effect
Endocrine:
Hyperprolactinaemia (galactorrhoea, gynaecomastia, oligo/amenorrhoea)
Haematological:
Agranulocytosis, leucopenia