Haloperidol is an antipsychotic medication available in injectable form [1]. It is used to manage psychotic disorders, control agitation and aggression, and treat Tourette's syndrome [2]. The injectable formulation allows for rapid onset of action, making it suitable for acute situations [3].
What is Haloperidol Injection Used For?
Haloperidol injection is prescribed for various conditions. It is primarily used to treat schizophrenia and other psychotic disorders. It is also effective in managing severe agitation and aggression in patients with these conditions [2]. Additionally, it can be used to control involuntary muscle movements and vocalizations associated with Tourette's syndrome [2]. The injectable form is particularly useful when rapid symptom control is necessary, such as in emergency psychiatric situations [3].
How Does Haloperidol Injection Work?
Haloperidol is a typical (first-generation) antipsychotic that works by blocking dopamine D2 receptors in the brain [4]. Dopamine is a neurotransmitter that plays a role in mood, behavior, and cognition. By blocking these receptors, haloperidol helps to reduce the positive symptoms of psychosis, such as hallucinations and delusions, and to calm agitated behavior [4].
What Are the Different Forms of Haloperidol Injection?
Haloperidol is available in several injectable forms, including a standard solution for intramuscular injection and a long-acting decanoate ester formulation for intramuscular injection [5]. The standard solution provides relatively rapid but short-term effects, while the decanoate ester formulation is designed for sustained release over several weeks [5].
How Long Does Haloperidol Injection Last?
The duration of action for haloperidol injection depends on the formulation. The standard intramuscular injection typically provides symptom relief within minutes to an hour, with effects lasting for several hours [3]. The haloperidol decanoate, a long-acting injectable, can provide therapeutic effects for up to four weeks after a single injection, reducing the need for daily oral medication [5].
What are the Risks and Side Effects of Haloperidol Injection?
Like all medications, haloperidol injection carries potential risks and side effects. Common side effects include drowsiness, dizziness, dry mouth, and constipation [1]. More serious side effects can include extrapyramidal symptoms (EPS), such as involuntary muscle movements, stiffness, tremors, and restlessness (akathisia) [4]. Neuroleptic Malignant Syndrome (NMS) is a rare but life-threatening reaction characterized by high fever, muscle rigidity, altered mental status, and autonomic instability [1]. Prolonged QT interval, which can lead to serious heart rhythm disturbances, is another potential cardiac risk [1].
When Does Haloperidol Patent Expiry Occur?
Haloperidol is a well-established medication, and its original patents have long since expired [6]. This means that generic versions of haloperidol injection are available, generally leading to lower costs [6]. DrugPatentWatch.com tracks patent information for pharmaceuticals, but as haloperidol is an older drug, its primary market exclusivity has expired [6].
Who Manufactures Haloperidol Injection?
Multiple pharmaceutical companies manufacture generic versions of haloperidol injection. These include companies like Fresenius Kabi, Hikma Pharmaceuticals, and others that produce injectable medications [7]. The specific manufacturers can vary by region and availability.