Prochlorperazine (Stemetil) Side Effects in Pakistan

A complete guide to Prochlorperazine (Stemetil) side effects — from common side effects to serious warnings and emergency signs. What to expect from this medicine and when it is necessary to see a doctor.

Compiled by the PakVita Editorial Team · AI-assisted drafting with editorial review · Sourced from DRAP, WHO, BNF · Last updated: 2026-06-17

Side Effects

Quick Answer

Common side effects of Prochlorperazine (Stemetil) include drowsiness, dry mouth, constipation, and dizziness. Serious effects include acute dystonia, tardive dyskinesia (long-term use), and Neuroleptic Malignant Syndrome (NMS — rare but life-threatening).

Side Effects at a Glance

Common

Sedation / drowsiness (avoid driving)
Dry mouth
Constipation
Blurred vision (anticholinergic effect)
Hypotension
Akathisia (restlessness — can't sit still)
Photosensitivity
Weight gain

Serious — See a Doctor

Acute dystonia — oculogyric crisis (eyes rolling back), torticollis (neck stiffening), trismus (jaw locking) — especially young patients — TREATABLE but seek emergency care
Tardive dyskinesia — long-term use se uncontrolled repetitive movements
Neuroleptic Malignant Syndrome (NMS) — rare: high fever, severe muscle rigidity, confusion, autonomic instability — LIFE-THREATENING EMERGENCY
QT prolongation / cardiac arrhythmia
Agranulocytosis (rare — phenothiazine class — infection risk)

When to See a Doctor Immediately

IMMEDIATE EMERGENCY: Neck stiffening, eyes rolling back, jaw tightening — acute dystonia — treatable with IM anticholinergic
IMMEDIATE EMERGENCY: High fever + severe muscle rigidity + confusion — NMS — life-threatening
Irregular heartbeat (QT prolongation)
Uncontrolled repetitive movements develop (tardive dyskinesia)
Severe hypotension or near-fainting
Persistent restlessness (akathisia) that cannot be tolerated

Prochlorperazine (Stemetil) Side Effects

Prochlorperazine (Stemetil) is generally effective in short-term use but awareness of extrapyramidal side effects — especially in young patients — is necessary.

Common Side Effects

Sedation / drowsiness (do not drive)
Dry mouth
Constipation
Blurred vision
Hypotension
Akathisia
Photosensitivity
Weight gain

Serious Side Effects (Immediate Action Required)

Acute Dystonia (TREATABLE EMERGENCY)

Especially in young patients — after a dose: neck stiffening (torticollis), eyes rolling back (oculogyric crisis), jaw locking (trismus). It is frightening but treatable — GO TO THE EMERGENCY ROOM IMMEDIATELY. An IM anticholinergic (biperiden) resolves it quickly.

Tardive Dyskinesia

After long-term use — uncontrolled repetitive movements (lip smacking, chewing movements, limb jerks). It can become permanent. Therefore short-term use only or specialist supervision is required for long-term use.

Neuroleptic Malignant Syndrome (NMS)

Rare but LIFE-THREATENING: high fever + severe muscle rigidity + confusion + autonomic instability. Discontinue the medicine immediately and go to the EMERGENCY room.

QT Prolongation / Cardiac Arrhythmia

Heart rhythm can become abnormal — especially when combined with other QT-prolonging drugs.

Agranulocytosis (Rare)

A phenothiazine class effect — white blood cells may decrease — the risk of infection increases.

When to See a Doctor

IMMEDIATE EMERGENCY: Neck stiffening or eyes rolling back (acute dystonia)
IMMEDIATE EMERGENCY: High fever + muscle rigidity + confusion (NMS)
Irregular heartbeat (QT)
Uncontrolled repetitive movements (tardive dyskinesia)
Severe hypotension / near-fainting

Side Effects Summary Table

Type	Side Effect	Action
Common	Drowsiness	Avoid driving
Common	Dry mouth / Constipation	Monitor / inform doctor
Common	Akathisia (restlessness)	Inform doctor — dose review
Serious	Acute dystonia	IMMEDIATE EMERGENCY
Serious	Tardive dyskinesia	Stop + doctor
Serious	NMS	LIFE-THREATENING EMERGENCY
Serious	QT prolongation	Cardiac monitoring

Reporting Side Effects

If you notice any unexpected side effect, report it on the DRAP pharmacovigilance portal: https://www.dra.gov.pk/pharmacovigilance

The information in this guide is for educational purposes only. If you notice any side effect, contact your doctor or pharmacist.

Frequently Asked Questions

Prochlorperazine ke sabse common side effects kya hain?

Common side effects include drowsiness, dry mouth, constipation, and dizziness. These are usually mild but avoid driving.

Acute dystonia kya hota hai aur kya karna chahiye?

In acute dystonia, the neck stiffens, the eyes roll back (oculogyric crisis), or the jaw locks tight. It is frightening but treatable. GO TO THE EMERGENCY ROOM IMMEDIATELY — an IM anticholinergic injection resolves it quickly.

NMS kya hai aur kaise pehchanein?

Neuroleptic Malignant Syndrome (NMS) is rare but life-threatening: high fever, severe muscle rigidity, confusion, and autonomic instability. Discontinue Prochlorperazine and GO TO THE HOSPITAL IMMEDIATELY.

Tardive dyskinesia kya hai?

Tardive dyskinesia results from long-term phenothiazine use — uncontrolled repetitive movements (chewing, lip smacking, limb movements) develop. It can become permanent. Therefore, specialist review is necessary for long-term use.

Kya prochlorperazine lene se neend aayegi?

Yes — drowsiness is a common side effect. Avoid driving or operating heavy machinery until you have assessed your tolerance.

Brand alternatives, same-class options, and other medicines used for the same conditions as Stemetil Tablet.

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Used for the same conditions

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Sources

DRAP Registered Products Database — Drug Regulatory Authority of Pakistan
WHO Model List of Essential Medicines, 23rd ed. (2023) — World Health Organization
British National Formulary (BNF) — BMJ Group & Pharmaceutical Press

Medical disclaimer

This page is for educational use only and does not replace professional medical advice. Always confirm diagnosis, dose, and interactions with a qualified doctor or pharmacist before starting or changing any medicine.