Haldol (Haloperidol)

Haloperidol injection is indicated for several acute psychiatric conditions where rapid symptom control is required, particularly when oral administration is impractical or when immediate therapeutic effect is desired.

• Management of acute exacerbations of schizophrenia.
• Treatment of acute psychotic episodes, including those associated with substance use.
• Control of manic episodes in bipolar disorder when oral therapy is not feasible.
• Rapid calming of severe agitation or aggression in emergency settings.
• Adjunctive use for pre‑operative sedation in patients at risk of delirium.

Like other antipsychotics, intramuscular haloperidol can produce a range of side effects that vary in frequency and severity.

Common

• Drowsiness or sedation.
• Extrapyramidal symptoms such as tremor, rigidity, or restlessness.
• Dry mouth, constipation, or blurred vision.
• Elevated prolactin levels causing menstrual changes or breast discomfort.
• Weight gain or metabolic changes.

Serious

• Neuroleptic malignant syndrome, a rare but life‑threatening reaction.
• Torsades de pointes or other significant cardiac arrhythmias.
• Severe hypotension or syncope.
• Persistent severe depression or suicidal thoughts.

Haloperidol injection should be used with caution, and clinicians consider several precautions before prescribing.

• Assess for a history of cardiovascular disease, as haloperidol may affect heart rhythm.
• Evaluate for extrapyramidal disorder risk, especially in patients with Parkinsonian features.
• Use carefully in patients with liver or kidney impairment due to altered drug clearance.
• Monitor for signs of neuroleptic malignant syndrome during the first few days of therapy.
• Avoid use in individuals with known hypersensitivity to haloperidol or other butyrophenones.
• Consider pregnancy and lactation status; safety data are limited.

Haloperidol can interact with other medications, influencing its efficacy or safety profile.

Avoid

• Other dopamine antagonists or antipsychotics, which may increase extrapyramidal risk.
• QT‑prolonging agents such as certain antiarrhythmics, macrolide antibiotics, or antimalarials.
• CNS depressants (e.g., benzodiazepines, opioids) that can enhance sedation.
• Alcohol, which can potentiate central nervous system depression.

Use with caution

• Anticholinergic drugs, which may mask early signs of extrapyramidal symptoms.
• CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) that can raise haloperidol plasma levels.
• CYP3A4 inducers (e.g., carbamazepine, rifampin) that may reduce therapeutic effect.
• Lithium, as combined use may increase risk of neurotoxicity.
• Other QT‑prolonging medications, requiring ECG monitoring.