Understanding Prochlorperazine Side Effects

Prochlorperazine is a phenothiazine medication prescribed for severe nausea and vomiting, schizophrenia, and short-term anxiety. Like all medications, it can cause side effects. Most are mild and go away on their own, but some need immediate medical attention.

This guide covers what to expect, what's considered normal, and the warning signs that mean you should call your doctor or go to the emergency room. If you're new to this medication, you may also want to read what Prochlorperazine is and how it's used.

Common Side Effects of Prochlorperazine

These side effects happen in many people who take Prochlorperazine. They're usually mild and often improve as your body adjusts to the medication over the first few days or weeks:

Drowsiness and Sedation

This is the most commonly reported side effect. Prochlorperazine works by blocking dopamine receptors in the brain, which can make you feel sleepy. Avoid driving or using heavy machinery until you know how the medication affects you.

What helps: Take your dose at bedtime if possible. Avoid alcohol and other sedating medications. Talk to your doctor if drowsiness is interfering with your daily life.

Dizziness

You may feel lightheaded, especially when standing up quickly. This happens because Prochlorperazine can lower blood pressure slightly.

What helps: Stand up slowly from sitting or lying positions. Stay hydrated. Hold onto something sturdy if you feel unsteady.

Dry Mouth

Prochlorperazine has anticholinergic effects that reduce saliva production.

What helps: Sip water throughout the day, chew sugar-free gum, or use over-the-counter saliva substitutes.

Constipation

The same anticholinergic effects that cause dry mouth can also slow down your digestive system.

What helps: Eat fiber-rich foods, drink plenty of water, and stay physically active. An over-the-counter stool softener may help if needed.

Blurred Vision

Some people notice temporary changes in their vision, especially during the first week of treatment.

What helps: This usually improves on its own. Avoid tasks that require sharp vision until it clears. See your doctor if it persists.

Nasal Congestion

A stuffy nose is a less well-known but common side effect.

What helps: Over-the-counter saline nasal spray can provide relief.

Movement-Related Side Effects (Extrapyramidal Symptoms)

Prochlorperazine can cause a group of side effects that affect your muscles and movements. These are called extrapyramidal symptoms (EPS), and they happen because the medication blocks dopamine in parts of the brain that control movement.

Akathisia (Restlessness)

You may feel an intense urge to move, pace, or fidget. This can feel very uncomfortable — like you can't sit still no matter how hard you try.

Dystonia (Muscle Spasms)

Involuntary muscle contractions, often in the neck, face, or back. This can happen suddenly, sometimes within the first few doses. Young adults and men are at higher risk.

Parkinsonism (Tremor and Stiffness)

Symptoms that look like Parkinson's disease — trembling hands, stiff muscles, shuffling walk, and a mask-like facial expression.

What to do about EPS: Report any of these symptoms to your doctor. They can adjust your dose, switch you to a different medication, or prescribe a medication like benztropine or diphenhydramine to help manage these effects. Do not stop Prochlorperazine suddenly without talking to your doctor.

Serious Side Effects: When to Call Your Doctor

Some side effects are rare but serious. Contact your doctor right away if you experience any of the following:

Tardive Dyskinesia

This involves involuntary, repetitive movements — often of the face, tongue, or jaw. You might notice lip smacking, tongue thrusting, or grimacing that you can't control. Tardive dyskinesia can develop after weeks, months, or years of use and may be permanent even after stopping the medication.

Action needed: Tell your doctor immediately. The earlier this is caught, the better the chance of it improving.

Neuroleptic Malignant Syndrome (NMS)

This is a rare but life-threatening reaction. Symptoms include:

• Very high fever (over 104°F / 40°C)
• Severe muscle rigidity
• Confusion or altered mental status
• Rapid heart rate
• Fluctuating blood pressure
• Excessive sweating

Action needed: Call 911 or go to the emergency room immediately. NMS requires emergency medical treatment.

Blood Disorders (Agranulocytosis)

Prochlorperazine can rarely affect your bone marrow's ability to make white blood cells. Warning signs include:

• Unexplained fever or chills
• Severe sore throat
• Mouth sores
• Signs of infection that won't go away

Action needed: Contact your doctor right away. A simple blood test can check your white blood cell count.

Heart Rhythm Changes (QT Prolongation)

Prochlorperazine can affect the electrical activity of your heart, especially if you take other medications that interact with it. Symptoms may include:

• Feeling like your heart is racing, pounding, or skipping beats
• Sudden dizziness or fainting
• Shortness of breath

Action needed: Seek immediate medical attention if you experience these symptoms.

Severe Low Blood Pressure

While mild dizziness is common, severe drops in blood pressure can cause fainting, especially when the medication is given by injection.

Seizures

Prochlorperazine lowers the seizure threshold. If you have a history of seizures or epilepsy, your doctor should know this before prescribing the medication. Seek emergency care if a seizure occurs.

Jaundice (Liver Problems)

Yellowing of the skin or eyes, dark urine, or severe abdominal pain could indicate liver damage. Contact your doctor immediately.

Important Boxed Warning

Prochlorperazine carries an FDA boxed warning — the most serious type of warning — about use in elderly patients with dementia-related psychosis. Studies have shown an increased risk of death in this population. Prochlorperazine is not approved for treating behavioral problems related to dementia.

Side Effects by Dosage Form

How you take Prochlorperazine can affect which side effects you experience:

• Oral tablets (5 mg, 10 mg): Most common route. Side effects tend to build gradually.
• Rectal suppositories (25 mg): Local irritation is possible. The higher dose may increase sedation.
• Injectable (IM/IV): Effects happen faster. Severe hypotension and acute dystonia are more likely with injections, especially IV administration.

Who Is More Likely to Have Side Effects?

Some groups are at higher risk for side effects from Prochlorperazine:

• Elderly patients: More sensitive to sedation, hypotension, and EPS
• Children: Higher risk of dystonia and other movement-related side effects; not approved for children under 2 years old
• People taking multiple medications: Drug interactions can increase side effects — see our drug interactions guide
• People with liver or kidney problems: The medication may be processed more slowly, increasing side effect risk

How to Manage Side Effects

Here are general tips for handling Prochlorperazine side effects:

1. Don't stop suddenly. Abruptly stopping can cause withdrawal symptoms. Talk to your doctor about tapering if you want to stop.
2. Track your symptoms. Write down any side effects, when they happen, and how severe they are. This information helps your doctor make adjustments.
3. Stay hydrated. Water helps with dry mouth, constipation, and dizziness.
4. Avoid alcohol. Alcohol increases sedation and other CNS effects.
5. Use sun protection. Phenothiazines can increase sun sensitivity. Wear sunscreen and protective clothing.
6. Keep all follow-up appointments. Regular check-ins let your doctor monitor for tardive dyskinesia and other long-term effects.

When Side Effects Mean You Need a Different Medication

If side effects are too bothersome or if you develop serious reactions, your doctor may switch you to an alternative medication. Common alternatives include Ondansetron (Zofran), Promethazine (Phenergan), and Metoclopramide (Reglan), though each has its own side effect profile.

Having trouble finding Prochlorperazine at your pharmacy? Learn about the current shortage situation or use MedFinder to check pharmacy stock near you. You can also save money on your prescription with coupon cards and assistance programs.