Treatment of schizophrenia when prolonged parenteral therapy required.


Individualize. Administer by deep IM every 4 weeks. Initial therapy: switching from oral form: initially 10–20 times previous daily dose of oral haloperidol. Stabilized on low daily oral dose, elderly, or debilitated: 10–15 times previous daily dose of oral haloperidol. Maintained on high dose antipsychotics, risk of relapse, or if tolerant: consider 20 times previous daily oral dose; then titrate downward subsequently. Max initial dose: 100mg; if conversion requires >100mg, then give balance in 3–7 days. Maintenance therapy: usual range: 10–15 times previous daily dose of oral haloperidol based on response. Max: 450mg/month.


Not established.


Severe CNS depression. Coma. Parkinsonism.

Boxed Warning:

Increased mortality in elderly patients with dementia-related psychosis.


Elderly with dementia-related psychosis (not approved use): increased risk of death. Risk of QT prolongation: electrolyte disturbances (eg, hypokalemia, hypomagnesemia), underlying cardiac abnormalities, hypothyroidism, familial long QT-syndrome, concomitant drugs known to prolong the QT interval. Seizures. Thyrotoxicosis. Pre-existing low WBCs or history of leukopenia/neutropenia; monitor CBCs during 1st few months of treatment; discontinue if WBCs decline. Severe cardiovascular disorders. Mania. Perform fall risk assessments when initiating and recurrently on long-term therapy. Avoid abrupt cessation. Debilitated. Neonates: risk of extrapyramidal and/or withdrawal symptoms post delivery (due to exposure during 3rd-trimester pregnancy). Pregnancy (Cat.C). Nursing mothers: not recommended.

See Also:

Pharmacologic Class:



CNS depression potentiated with alcohol, other CNS depressants. Possible neurotoxicity with lithium: monitor, discontinue if occurs. Caution with drugs that prolong the QT interval (eg, ketoconazole, paroxetine). May be potentiated by CYP3A4 or CYP2D6 inhibitors/substrates (eg, itraconazole, nefazodone, buspirone, venlafaxine, alprazolam, fluvoxamine, quinidine, fluoxetine, sertraline, chlorpromazine, promethazine. May be antagonized by CYP3A4 inducers (eg, rifampin, carbamazepine); monitor and adjust doses. May increase intraocular pressure with anticholinergics, antiparkinson agents. Monitor anticoagulants.

Adverse Reactions:

Tardive dyskinesia, neuroleptic malignant syndrome, extrapyramidal symptoms, hyperpyrexia, heat stroke, bronchopneumonia, cardiovascular effects, hematological effects, GI upset, anticholinergic effects; QT prolongation, Torsades de Pointes, dystonia.

How Supplied:

Inj (1mL amps)—10; Decanoate 50 (1mL amps)—3; Decanoate 100 (1mL amps)—5