Overview
Uses and benefits
Side effects
How to use
How drug works
Safety advice
Missed dose
All substitutes
Quick tips
Fact box
Interaction with drugs
Patient concerns
FAQs

Author Details

Written By

Dr. Swati Mishra

BDS

Reviewed By

Dr. Rajeev Sharma

MBA, MBBS

Last updated

04 Jan 2026 | 12:08 PM (IST)

We provide you with authentic, trustworthy and relevant information

Want to know more

Have issue with the content?

Report Problem

Phenergan 2.5% Injection

Prescription Required

Marketer

Abbott

SALT COMPOSITION

Promethazine (2.5% w/v)

Storage

Store below 30°C

Product introduction

Phenergan 2.5% Injection is a systemic antihistamine used to relieve allergic reactions such as itching, sneezing, and rashes. It works by blocking histamine, a substance released during allergies, helping reduce allergy symptoms and discomfort.

Phenergan 2.5% Injection is given as an injection under the supervision of healthcare professionals. It should be taken as your doctor's advice. The dose and how often you take it depends on what you are taking it for. Your doctor will decide how much you need to improve your symptoms. You should take this medicine for as long as it is prescribed for you. You must inform your doctor if symptoms do not improve within 7 days of the treatment.

The most common side effects of this medicine include drowsiness, restlessness, headache, and tiredness. There may be ways of reducing or preventing them. It makes the skin more sensitive towards sunlight. Use sunscreen or wear protective clothing before going out.

Before taking this medicine, let your doctor know if you have glaucoma or have asthma issues, or have high blood pressure. Inform your doctor if you are pregnant, or breastfeeding. Your doctor should also know about all other medicines you are taking as many of these may make this medicine less effective or change the way it works. Generally, it is advised to avoid alcohol while on treatment.

Uses of Phenergan Injection

Treatment of Allergic conditions

Benefits of Phenergan Injection

In Treatment of Allergic conditions

Phenergan 2.5% Injection is used to treat many different inflammatory and allergic conditions. It works by lowering your immune system’s response to these conditions and prevents the release of substances in the body that cause inflammation. It helps relieve symptoms such as swelling, pain, itching, and other allergic-type reactions. If you are not sure why you are being given this medicine, ask your doctor.

This medicine is given orally (by mouth). You should always take it as it has been prescribed for you. Do not stop taking it without your doctor’s advice. This can cause unpleasant withdrawal symptoms. Because this medicine weakens your immune system, you should avoid being near people who are ill or have infections.

Side effects of Phenergan Injection

Most side effects do not require any medical attention and disappear as your body adjusts to the medicine. Consult your doctor if they persist or if you’re worried about them

Common side effects of Phenergan

Tiredness

How to use Phenergan Injection

Your doctor or nurse will give you this medicine. Kindly do not self administer.

How Phenergan Injection works

Phenergan 2.5% Injection is an antiallergic medication. When your body is exposed to an allergen (pollen, animal dander, house dust etc.), it produces a chemical called histamine. This causes watery eyes, runny or blocked nose, sneezing, skin rashes, itching etc. Phenergan 2.5% Injection works by blocking the action of histamine, thereby relieving these symptoms. It also works directly on several areas of the brain to prevent nausea/vomiting and help you feel more relaxed.

Safety advice

Alcohol

UNSAFE

Do not drink alcohol while you are taking this medicine. Phenergan 2.5% Injection may cause excessive drowsiness when taken with alcohol.

Pregnancy

CONSULT YOUR DOCTOR

Phenergan 2.5% Injection is not recommended during pregnancy as there is positive evidence of fetal risk based on animal studies. However, it may still be prescribed by a doctor in situations where the benefits outweigh the risks.

Breast feeding

CONSULT YOUR DOCTOR

Information regarding the use of Phenergan 2.5% Injection during breastfeeding is not available. Please consult your doctor.

Driving

UNSAFE

Phenergan 2.5% Injection may decrease alertness, affect your vision, or make you feel sleepy and dizzy. Do not drive if these symptoms occur.

Kidney

CAUTION

Phenergan 2.5% Injection should be used with caution in patients with kidney disease. Dose adjustment may be needed.

Liver

CAUTION

Phenergan 2.5% Injection should be used with caution in patients with severe liver disease. Dose adjustment may be needed.

What if you forget to take Phenergan Injection?

If you miss a dose of Phenergan 2.5% Injection, please consult your doctor.

All substitutes

For informational purposes only. Consult a doctor before taking any medicines.

No substitutes found for this medicine

Quick tips

Phenergan 2.5% Injection helps treat nausea, vomiting and allergic conditions.
Use caution while driving or doing anything that requires concentration as Phenergan 2.5% Injection can cause dizziness and sleepiness.
Do not drink alcohol while taking this medication as it may cause increased sleepiness.
It may make your skin more sensitive to sunlight. Avoid exposing your skin to strong sunlight, use a sunscreen lotion or make sure your skin is protected with clothing.
Do not take it for longer than 7 days. If your symptoms worsen or do not improve after 7 days, talk to your doctor.
Stop taking it at least three days before taking an allergy test as it can affect the test results.
Avoid driving or operating dangerous machinery as it may decrease alertness.
Avoid consuming alcohol when taking the Phenergan 2.5% Injection, as it may cause excessive sleepiness or drowsiness.

Fact Box

Chemical Class

Phenothiazines

Habit Forming

Therapeutic Class

RESPIRATORY

Action Class

First-Generation H1 Antihistamines

Interaction with drugs

Taking Phenergan with any of the following medicines can modify the effect of either of them and cause some undesirable side effects

Tranylcypromine (Oral Route) Life-threatening

Clozapine (Oral Route) Moderate

Watch out for symptoms such as dry mouth, increased heart rate, urination difficulties, constipation, loss of appetite or nausea and consult your doctor if you experience them. Co... More

Trihexyphenidyl (Oral Route) Moderate

Talk to your doctor if you notice any unusual symptoms. Concurrent use may cause dry mouth, blurred vision, urinary retention, constipation, and confusion.

Trihexyphenidyl (Injection Route) Moderate

Talk to your doctor if you notice any unusual symptoms. Concurrent use may cause dry mouth, blurred vision, urinary retention, constipation, and confusion.

Lorazepam (Oral Route) Moderate

Do not drive or do anything requiring concentration or alertness until you know how the medicines affect you. Concurrent use may increase sleepiness.

View all drug interactions

Patient concerns

My daughter is suffering from cold and fever should i give him phenergan

Dr. Gopal Bansilal Samdani

Paediatrics

no need of phenarganMonitor temp . Place a cool, damp washcloth on your child's forehead , Give your child a lukewarm tub bath or a sponge bath. Give a sponge bath as follows:- ? Use lukewarm water [90?F (32.2?C) to 95?F (35?C)] . Do not use cold water, ice, or rubbing alcohol, which will lower the child's body temperature too quickly. ? Sponge for 20 to 30 minutes. ? Stop if the child starts to shiver. If your child doesn't like the sponge bath or doesn't feel better after the bath, there is no need to give another one. You can use Paracetamol also along with above measures to control fever till you consult Dr.There are many underlying causes of your symptoms. Different cause needs different treatment. Specific treatment cannot be given unless we establish exact underlying cause. Final and perfect diagnosis cannot be done without doing clinical examination of child. Please consult me or any other Paediatrician. will take detail history and will examine your child in detail. At time may ask you relevant investigations if necessary. All information will be used to determine exact underlying cause of problem. Depending upon cause will prescribe you treatment. Your child may need antibiotics. It is mandatory for the customer to have a prescription for the prescription medicines he/she is procuring. Valid prescription cannot be given without diagnosis.

Always he suffer from coughing and looses his weight. Few days ago PATIENT phenergan drops. Now PATIENT from dry cough.

Dr. Rahul Yadav

Paediatrics

Hello, please start syp chericoff 2.5 ml twice daily for the next 5 days. Also nasoclear nasal drops SOS for nasal blockage. Give lukewarm water and fluids to drink.

She is 6 months old and has got cough cold from past one week . sometimes fever also. what medicine . prescribed phenergan but not much help

Dr. Gopal Bansilal Samdani

Paediatrics

For cough, cold -- Prevent dehydration. Fluids may help thin secretions and soothe an irritated throat. Dry, hacking coughs respond to honey in hot water, tea, or lemon juice. Drink plenty of fluids to replace those lost from sweating and having a runny nose, get plenty of rest, eat healthily ? a low-fat, high-fibre diet is recommended, including plenty of fresh fruit and vegetables. OTC drugs, gargling with salt water and sucking on menthol sweets can help relieve a sore throat and blocked nose, are generally safe for older children and adults to take, but might not be suitable for babies, young children. Avoid applying Vicks VapoRub to babies and toddlers.You should never give children under 4 years of age over-the-counter cough and cold products without checking with your child's doctor. These medicines may harm young children. There are many underlying causes of cough and cold. Different cause needs different treatment. Specific treatment cannot be given unless we establish exact underlying cause. Final and perfect diagnosis cannot be done without doing clinical examination of patient. Please consult me or any other Paediatrician. will take detail history and will examine patient in detail. All information will be used to determine exact underlying cause of problem. Depending upon cause will prescribe you specific treatment.

Ive got tested for hiv after 4 months of possible exposure (not sure if partner was +ve and sex was with condom) and results were negative and its been 6 months till date after the possible exposure now i was suffering from blocked nose wnd difficulty in breathing so i went to a chest specialist and was given total ige" test and the report came +ve with very highly elevated ige levels about 2000 ku/l is there anything to worry and is there any relation between total ige levels and hiv im very stressed once again please help."

Dr. Sunil Sekhri

Diabetology

IgE levels indicate that the conditions is allergic

Is Phenergan 2.5% Injection or Phenergan 2.5% Injection DM syrup a narcotic/opiate/pain killer?

Phenergan 2.5% Injection is antihistaminic drug and not a narcotic/opiate/pain killer. Patient should follow the advice of doctor regarding its use

Is Phenergan 2.5% Injection over the counter?

No, it is available with doctor's prescription only

Can I take Phenergan 2.5% Injection for a hangover/sore throat/ nausea/stomach flu/cramps/toothache/ headache/ cough/pain?

Phenergan 2.5% Injection is used for treatment of symptoms of allergies, but not used for hangover, sore throat, stomach flu, cramps, toothache, headache and cough. Patient should follow the advice of doctor regarding its use

Can I take Phenergan 2.5% Injection with Nyquil/ codeine and ibuprofen/ Tylenol/ oxycodone/ Benadryl/ Dayquil/ Zofran/codeine and Nyquil/Xanax?

Yes, but taking other medicines may alter the effects of Phenergan 2.5% Injection. Always consult your doctor for the change of dose regimen or an alternative drug of choice that may strictly be required

Does Phenergan 2.5% Injection or Phenergan 2.5% Injection DM make you sleepy/ get you high/make you tired?

Phenergan 2.5% Injection may cause these side effects which are not serious. However, always consult your doctor if you experience any of these side effects.

Show less

Related lab tests

Absolute Eosinophil Count

Peripheral Smear Examination

Total IgE

Top Physicians

5 ★

5 ★

3.8 ★

MBBS, MD, Diploma, Diploma

5 ★

Dr. ( Maj.) Mukesh Dwivedi

MBBS, Diploma, Certification

5 ★

Want to share the information?

Disclaimer:

Tata 1mg's sole intention is to ensure that its consumers get information that is expert-reviewed, accurate and trustworthy. However, the information contained herein should NOT be used as a substitute for the advice of a qualified physician. The information provided here is for informational purposes only. This may not cover everything about particular health conditions, lab tests, medicines, all possible side effects, drug interactions, warnings, alerts, etc. Please consult your doctor and discuss all your queries related to any disease or medicine. We intend to support, not replace, the doctor-patient relationship.

References

Briggs GG, Freeman RK, editors. A Reference Guide to Fetal and Neonatal Risk: Drugs in Pregnancy and Lactation. 10th ed. Philadelphia, PA: Wolters Kluwer Health; 2015. pp. 1159-60.
Promethazine. Guildford, Surrey: SANOFI; 2002 [revised 17 Aug. 2016] (online) Available from:
Chaves RG, Lamounier JA. Breastfeeding and maternal medications. J Pediatr (Rio J). 2004;80(5 Suppl):S189-S198. [Accessed 01 Apr. 2019] (online) Available from:
Promethazine hydrochloride. Xiangyang, Hubei. Tianjin kingyork group hubei tianyao pharmaceutical co.,ltd. [Accessed 04 Jan. 2026] (online). Available from: