Haldol

Haldol is a prescription intramuscular injection that contains the active ingredient haloperidol, a butyrophenone antipsychotic. It is marketed in the European Union and is supplied without a specified strength in this description. Haloperidol works primarily as a dopamine D2 receptor antagonist and is used under medical supervision for certain psychiatric conditions. It is classified under ATC code N05AD01 and is typically administered by a healthcare professional in acute care settings.

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.