Haloperidol Mercury Pharmaceuticals (Haloperidol)

Haloperidol injectable solution is indicated for the management of several acute psychiatric conditions.

• Schizophrenia, particularly during acute exacerbations where rapid symptom control is needed.
• Acute psychotic episodes associated with mood disorders, providing intramuscular sedation.
• Severe agitation or aggression requiring prompt tranquilization in emergency settings.
• Pre‑operative sedation for patients with known psychosis to ensure safe anesthesia.
• Management of delirium when oral antipsychotics cannot be administered.

Haloperidol may cause a range of adverse effects that differ in frequency and severity.

Common

• Drowsiness or sedation, which may affect alertness and daily activities.
• Extrapyramidal symptoms such as tremor, muscle rigidity, akathisia, or dystonia.
• Dry mouth, increased salivation, and other anticholinergic‑like sensations.
• Constipation, abdominal discomfort, or reduced gastrointestinal motility.
• Blurred vision or difficulty focusing.
• Weight changes, including possible loss of appetite.

Serious

• Neuroleptic malignant syndrome, a rare but life‑threatening reaction characterized by fever, muscle rigidity, and autonomic instability.
• Tardive dyskinesia, involving involuntary, repetitive movements that may persist after discontinuation.
• Cardiac arrhythmias, especially QT interval prolongation that can lead to torsades de pointes.
• Severe hypotension or cardiovascular collapse in susceptible individuals.
• Hepatic dysfunction presenting as elevated liver enzymes.

Haloperidol should be prescribed and monitored by a qualified healthcare professional.

• Assess cardiovascular status, including ECG, before initiating therapy due to potential QT prolongation.
• Monitor for early signs of extrapyramidal symptoms, especially in patients with prior movement disorders.
• Use caution in individuals with a history of seizures, CNS depression, or Parkinsonian features.
• Evaluate liver and kidney function periodically, adjusting dose if impairment is detected.
• Avoid abrupt discontinuation; taper the dose to reduce risk of rebound psychosis or withdrawal.
• Consider pregnancy and lactation status; the safety profile is not well established.
• Educate patients and caregivers about the need to report any sudden fever, muscle rigidity, or cardiac symptoms promptly.

Haloperidol can interact with several other medicines, influencing its safety or effectiveness.

Avoid

• Other dopamine antagonists such as metoclopramide, which may increase the risk of extrapyramidal side effects.
• Drugs that prolong the QT interval (e.g., certain antiarrhythmics, macrolide antibiotics, fluoroquinolones), heightening cardiac risk.
• Central nervous system depressants, including high‑dose benzodiazepines, when excessive sedation is a concern.

Use with caution

• Anticholinergic agents used to treat EPS, as they may mask early movement‑disorder symptoms.
• Strong CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) that can raise haloperidol plasma concentrations.
• CYP3A4 inducers (e.g., rifampin, carbamazepine) that may reduce haloperidol effectiveness.
• Other psychotropic drugs, requiring close monitoring for additive sedation or cardiac effects.