Haldol Decanoat (Haloperidol Decanoate)

Haloperidol decanoate is indicated for the treatment of several psychotic conditions where long‑term control is required.

• Schizophrenia, including maintenance therapy after stabilization.
• Acute psychotic episodes when oral therapy is not feasible.
• Chronic psychotic disorders such as schizoaffective disorder.
• Situations requiring improved adherence, such as patients with a history of non‑compliance.
• Adjunctive use in combination with oral antipsychotics during transition periods.
• Long‑acting injectable therapy for patients who have responded to oral haloperidol and need a depot formulation.
• Management of relapse prevention in individuals stabilized on haloperidol who require less frequent dosing.

The safety profile of haloperidol decanoate, like other long‑acting antipsychotics, may cause side effects that range from mild and transient to severe and potentially permanent. Patients and clinicians should be aware of the typical reactions as well as the rarer, more serious complications that require prompt medical attention.

Common

• Drowsiness or sedation.
• Extrapyramidal symptoms such as tremor, rigidity, or akathisia.
• Dry mouth and increased salivation.
• Constipation or gastrointestinal discomfort.
• Weight gain or changes in appetite.
• Blurred vision or dizziness.

Serious

• Neuroleptic malignant syndrome, a rare but life‑threatening reaction.
• Tardive dyskinesia, characterized by involuntary movements after prolonged use.
• Significant cardiac arrhythmias, including QT prolongation.
• Severe hypotension or orthostatic dizziness, especially after the first injection.

When prescribing haloperidol decanoate, clinicians should consider several precautionary measures to minimize risks and ensure appropriate patient selection.

• Assess cardiovascular status, including ECG, because the drug may prolong QT interval.
• Evaluate for a history of movement disorders or tardive dyskinesia before initiating therapy.
• Use caution in patients with hepatic impairment, as metabolism may be reduced.
• Monitor elderly patients closely for sedation, falls, and orthostatic hypotension.
• Discuss pregnancy and lactation status; the safety profile in these populations is not well established.
• Review concomitant medications that affect dopamine pathways to avoid additive effects.
• Ensure proper injection technique to avoid intravascular administration and local tissue injury.

Haloperidol decanoate can interact with other medicines, altering its effectiveness or increasing the risk of adverse events.

Avoid

• Concurrent use with other dopamine antagonists or high‑potency antipsychotics, which may intensify extrapyramidal effects.
• Co‑administration with medications known to significantly prolong the QT interval, such as certain antiarrhythmics or macrolide antibiotics.

Use with caution

• CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) that can raise plasma levels of haloperidol.
• CYP3A4 inducers (e.g., carbamazepine, rifampin) that may reduce drug concentrations.
• Central nervous system depressants, including benzodiazepines or opioids, which can enhance sedation.
• Anticholinergic agents that may mask early signs of extrapyramidal symptoms.