Prochlorperazine

Nausea and Vomiting

Prochlorperazine is frequently prescribed to manage severe nausea and vomiting. It is used to control these symptoms when they are caused by various medical conditions or treatments, such as surgery or radiation therapy.

Mental and Emotional Conditions

This medication is used to treat the manifestations of psychotic disorders, such as schizophrenia. It helps manage symptoms that may include hallucinations, delusions, and disorganized thinking.

Anxiety

Prochlorperazine may be used for the short-term treatment of generalized non-psychotic anxiety. It is typically reserved for situations where the anxiety is severe and has not responded adequately to other types of medication.

Mechanism of Action

Prochlorperazine works by blocking dopamine receptors in the brain. Dopamine is a chemical messenger that transmits signals between nerve cells. By interfering with these signals, the medication can help stabilize brain activity and reduce specific symptoms.

Control of Nausea and Vomiting

To prevent or treat nausea and vomiting, prochlorperazine acts on a specific area of the brain called the chemoreceptor trigger zone. By blocking dopamine in this region, the drug helps suppress the signals that trigger the urge to vomit.

Effects on Mental Health

When used for mental health conditions like schizophrenia or severe anxiety, prochlorperazine helps regulate brain chemistry. It alters the effects of dopamine and other substances to help reduce agitation, hallucinations, and other symptoms associated with these conditions.

Common Side Effects

Prochlorperazine may cause several common side effects. Consult your doctor if these symptoms are severe or do not go away:

• Drowsiness or dizziness
• Blurred vision
• Dry mouth or stuffy nose
• Constipation
• Difficulty sleeping (insomnia)
• Jitteriness or agitation
• Breast swelling or discharge
• Missed menstrual periods
• Weight gain or swelling in the hands or feet

Serious Side Effects

Seek medical attention immediately if you experience any of the following serious side effects:

• Uncontrolled movements: Tremors, muscle spasms, or rhythmic movements of the face, jaw, mouth, or tongue (tardive dyskinesia).
• Neuroleptic Malignant Syndrome: High fever, muscle rigidity, confusion, sweating, and irregular pulse or blood pressure.
• Infection signs: Fever, sore throat, and chills, which may indicate a low white blood cell count.
• Liver problems: Yellowing of the skin or eyes (jaundice).
• Severe reactions: Seizures, skin rash, hives, or swelling of the face, lips, and throat.
• Vision changes: Difficulty seeing at night or other persistent changes in vision.
• Difficulty urinating.

Boxed Warning: Dementia-Related Psychosis

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Prochlorperazine is not approved for the treatment of patients with dementia-related psychosis.

Contraindications

Prochlorperazine is contraindicated in patients who are in a comatose state or who have consumed large amounts of central nervous system depressants, such as alcohol, barbiturates, or narcotics. It is not for use in children under 2 years of age or weighing less than 20 pounds. It is also contraindicated for use in pediatric surgery or in individuals with a known hypersensitivity to phenothiazines.

Serious Neurological Conditions

• Neuroleptic Malignant Syndrome (NMS): This is a rare but potentially fatal reaction to antipsychotic drugs. Symptoms include high fever, muscle stiffness, confusion, and irregular heart rate or blood pressure.
• Tardive Dyskinesia: Long-term use may lead to involuntary, potentially irreversible muscle movements, particularly in the face and tongue. The risk increases with the duration of treatment and total cumulative dose, especially in elderly patients.
• Extrapyramidal Symptoms: Patients may experience acute dystonic reactions, such as spasms of the neck or back muscles, or motor restlessness. These reactions are more common in children and young adults.

Blood and Liver Precautions

There is a risk of serious blood disorders, including agranulocytosis, leukopenia, and neutropenia. Patients with a history of low white blood cell counts or those taking other medications that affect blood counts may require frequent monitoring. Additionally, the medication is used with caution in individuals with impaired liver function or a history of jaundice.

General Precautions

Seizure Threshold: Prochlorperazine may lower the threshold for seizures, requiring caution in patients with a history of epilepsy or those receiving treatments that also lower the seizure threshold.

Hypotension: A significant drop in blood pressure may occur, particularly with injectable forms. Patients are typically advised to remain lying down for at least 30 minutes after receiving an injection.

Environmental Sensitivity: This drug can interfere with the body's ability to regulate temperature, increasing the risk of heatstroke in hot environments. It may also cause skin to become more sensitive to sunlight, increasing the risk of severe sunburn.

Pregnancy and Breastfeeding

Use during pregnancy is generally limited to situations where the potential benefit justifies the potential risk to the fetus. Newborns exposed to antipsychotic drugs during the third trimester are at risk for extrapyramidal or withdrawal symptoms after delivery, such as agitation, feeding problems, or respiratory distress.

Pregnancy

There is limited information regarding the safety of prochlorperazine during pregnancy. It is generally recommended only when clearly needed and after a discussion with a healthcare provider about potential risks and benefits.

Using prochlorperazine during the third trimester of pregnancy may cause problems in the newborn after delivery. These symptoms, known as extrapyramidal or withdrawal symptoms, may include:

• Tremors or muscle stiffness
• Muscle weakness
• Sleepiness
• Difficulty breathing
• Feeding problems
• Agitation

If you become pregnant while taking this medication, contact your healthcare provider to discuss your treatment plan.

Breastfeeding

It is not known whether prochlorperazine passes into human breast milk. Because many medications can be transferred through milk and potentially affect a nursing infant, caution is recommended. Consult a healthcare provider to weigh the benefits of breastfeeding against the potential risks to the infant while using this medication.

Available Forms

Prochlorperazine is provided in several different forms to accommodate various medical needs:

• Oral Tablets: Standard tablets taken by mouth.
• Oral Extended-Release Capsules: Long-acting capsules designed for gradual release.
• Rectal Suppositories: Formulated for rectal administration.
• Injectable Solution: Administered by a healthcare provider via intramuscular injection or intravenous infusion.

FDA Approval and Indications

Prochlorperazine is approved by the U.S. Food and Drug Administration (FDA) for the management of severe nausea and vomiting of various causes. It is also indicated for the treatment of schizophrenia and for the short-term treatment of generalized non-psychotic anxiety.

Boxed Warning

The FDA requires a boxed warning for prochlorperazine because elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Prochlorperazine is not approved for the treatment of patients with dementia-related psychosis.

Pediatric Regulatory Status

The FDA has established specific age and weight restrictions for the use of prochlorperazine in children. It is contraindicated for use in pediatric patients under 2 years of age or weighing less than 20 pounds. Due to the risk of severe extrapyramidal reactions, its use in children should be limited to conditions where the potential benefits clearly outweigh the risks.

Safety Warnings

Regulatory labeling includes warnings for several serious conditions associated with prochlorperazine use:

• Tardive Dyskinesia: A syndrome of potentially irreversible, involuntary movements that may develop in patients treated with antipsychotic drugs.
• Neuroleptic Malignant Syndrome (NMS): A potentially fatal symptom complex characterized by hyperpyrexia, muscle rigidity, and autonomic instability.
• Falls: Prochlorperazine may cause somnolence, motor instability, and orthostatic hypotension, which can lead to falls and subsequent injuries.

Withdrawal Symptoms

Stopping prochlorperazine suddenly after long-term use or high doses can cause physical symptoms. These effects are more likely to occur if the body has become accustomed to the medication over time.

Commonly reported withdrawal symptoms include:

• Nausea and vomiting
• Dizziness
• Shakiness or trembling
• Stomach inflammation or discomfort (gastritis)

How to Stop Safely

It is important to follow a doctor's instructions when discontinuing prochlorperazine. A healthcare provider will typically create a schedule to slowly decrease the dose. This tapering process helps the body adjust and reduces the risk of unpleasant side effects. In some instances, a doctor may recommend continuing other specific medications for a few weeks after stopping prochlorperazine to help manage the transition.