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    DEA Class; Rx

    Common Brand Names; Inapsine

    • Antiemetic Agents; 

    Parenteral butyrophenone derivative, sedative-hypnotic structurally similar to haloperidol; more potent antiemetic, but less antipsychotic properties compared to haloperidol; due to the risk of QT prolongation and torsade de pointes, limited indication for surgical nausea and vomiting prophylaxis in patients refractory to other treatments.

    Indicated for nausea/vomiting prophylaxis associated with diagnostic procedures and for post-operative nausea/vomiting (PONV) prophylaxis.

    For sedation induction of the acutely agitated and/or violent patient (i.e., chemical restraint).
    For treatment of anxiety prior to induction of anesthesia (preanesthesia).
    For the acute treatment of migraine.
    For the treatment of post-operative nausea/vomiting (PONV).

    Known or suspected QT prolongation (eg, QTc interval greater than 440 msec for males or 450 msec for females); including patients with congenital long QT syndrome

    Any use other than for treatment of perioperative nausea and vomiting in patients for whom other treatments are ineffective or inappropriate

    • Restlessness
    • Anxiety
    • Extrapyramidal Symptoms
    • Dystonic reactions
    • Pseudoparkinsonian signs and symptoms
    • Tardive dyskinesia
    • Seizure
    • Altered central temperature regulation
    • Sedation
    • Drowsiness
    • Prolonged QT interval (dose dependent)
    • Swelling of breasts
    • Weight gain
    • Constipation
    • Hallucinations
    • Persistent tardive dyskinesia
    • Akathisia
    • Orthostatic hypotension
    • Tachycardia
    • ECG: abnormal T waves
    • Hypertension
    • Nausea
    • Vomiting
    • Dysuria

    Cases of QT prolongation and serious arrhythmias (eg, torsade de pointes, ventricular arrhythmias, cardiac arrest, and death) reported during post-marketing treatment with this drug; some cases have occurred in patients with no known risk factors and at doses at or below recommended doses; there has been at least one case of nonfatal torsade de pointes confirmed by rechallenge

    All patients should undergo a 12-lead ECG prior to administration of this drug to determine if a prolonged QT interval (eg, QTc > 440 msec for males or 450 msec for females) is present; if there is a prolonged QT interval, this drug should not be administered; for patients in whom the potential benefit of the treatment is felt to outweigh risks of potentially serious arrhythmias, ECG monitoring should be performed prior to treatment and continued for 2-3 hours after completing treatment to monitor for arrhythmias; vital signs and ECG should be monitored routinely

    Fluids and other countermeasures to manage hypotension should be readily available

    As with other CNS depressant drugs, patients who have received this drug should have appropriate surveillance

    Recommended that opioids, when required, initially be used in reduced doses

    As with other neuroleptic agents, very rare reports of neuroleptic malignant syndrome (altered consciousness, muscle rigidity, and autonomic instability) reported in patients who have received this drug

    Since it may be difficult to distinguish neuroleptic malignant syndrome from malignant hyperpyrexia in the perioperative period, consider prompt treatment with dantrolene if increases in temperature, heart rate, or carbon dioxide production occur

    Appropriately reduce initial dose of this drug in the elderly, debilitated, and other poor-risk patients; effect of initial dose should be considered in determining incremental doses

    Since this drug may decrease pulmonary arterial pressure, this fact should be considered by those who conduct diagnostic or surgical procedures where interpretation of pulmonary arterial pressure measurements might determine final management of the patient

    When the EEG is used for postoperative monitoring, it may be found that the EEG pattern returns to normal slowly

    There are no adequate and well-controlled studies in pregnant women. Inapsine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus

    Not known whether this drug is excreted in human milk; because many drugs are excreted in human milk, caution should be exercised when Inapsine is administered to a nursing mother


    2.5 mg IM/IV as an initial dose for most indications; dosage may be carefully titrated but should not exceed maximum recommendations per indication.


    2.5 mg IM/IV as an initial dose for most indications; dosage may be carefully titrated but should not exceed maximum recommendations per indication.


     2.5 mg IM/IV as an initial dose.


    >= 2 years: 0.1 mg/kg IM/IV as an initial dose.
    < 2 years: Safety and efficacy have not been established.


    injectable solution

    • 2.5mg/mL