Haldol (Haloperidol)

Haldol intramuscular injection is employed in several psychiatric and neurologic situations where a rapid onset of action is desired.

• Management of acute agitation associated with schizophrenia or other psychotic disorders.
• Control of severe manic episodes in bipolar disorder when oral therapy is insufficient.
• Treatment of acute psychosis in patients unable to take oral medication.
• Adjunctive therapy for severe behavioral disturbances in dementia or delirium.
• Short‑term use for pre‑operative sedation in selected cases.

Side effects of haloperidol administered intramuscularly vary in frequency and severity, ranging from mild, transient reactions to rare but serious events.

Common

• Drowsiness or sedation, often occurring shortly after injection.
• Restlessness or akathisia, presenting as an inner sense of unease.
• Dry mouth and reduced salivation.
• Blurred vision or mild visual disturbances.
• Constipation or gastrointestinal slowdown.

Serious

• Extrapyramidal symptoms such as acute dystonia, rigidity, or parkinsonism.
• Neuroleptic malignant syndrome, characterized by fever, muscle rigidity, and autonomic instability.
• Cardiac arrhythmias, including QT interval prolongation and potential torsades de pointes.
• Severe hypotension or orthostatic dizziness.

When using intramuscular haloperidol, clinicians should evaluate patient history and monitor for specific safety concerns to minimize risk.

• Assess for a history of cardiovascular disease, especially arrhythmias.
• Evaluate for prior extrapyramidal reactions or movement disorders.
• Use caution in patients with hepatic or renal impairment.
• Monitor elderly patients closely due to increased sensitivity and risk of delirium.
• Avoid use in individuals with known hypersensitivity to haloperidol or its excipients.
• Consider pregnancy and lactation status, as safety data are limited.
• Ensure appropriate dosing intervals to reduce accumulation.

Haloperidol can interact with several medications, affecting its efficacy or increasing the likelihood of adverse effects.

Avoid

• Concurrent use with other potent dopamine antagonists, which may amplify extrapyramidal side effects.
• Co‑administration with drugs that significantly prolong the QT interval, such as certain antiarrhythmics or macrolide antibiotics.
• Combining with strong CYP3A4 inhibitors that raise haloperidol plasma levels.

Use with caution

• Use with CYP3A4 inducers (e.g., carbamazepine, phenytoin) as they may reduce therapeutic effect.
• Concomitant use of central nervous system depressants, including benzodiazepines or opioids, may enhance sedation.
• Interaction with anticholinergic agents may mask early signs of extrapyramidal symptoms.