This content has been checked for quality and accuracy by

James O'Loan Superintendent Pharmacist

What is Phenergan and when is it used?

Belonging to a group known as phenothiazines, which work by changing the actions of chemicals in the brain and acts as a anti-histamine, Phenergan can be used to treat allergy symptoms such as itching, runny nose, sneezing, itchy or watery eyes, hives, and itchy skin rashes.

This medication can also be used to help prevent motion sickness, treat nausea and vomiting or pain relief after surgery. It can also be used as a sedative or sleeping aid

How will it treat my symptoms?

The active ingredient is promethazine which is known as a sedating antihistamine. It works by preventing the actions of histamine in the body

Histamine is produced naturally by the body as a defense mechanism and causes symptoms of allergic reactions. Promethazine blocks histamine and prevents it from binding to receptors in the body which stops it from producing these symptoms.

Due to the active ingredient, Phenergan can also block histamine receptors in the vomit centre of the brain which is activated when it receives signals from the vestibular apparatus. This is will help prevent symptoms of motion sickness and vertigo such as nausea, dizziness or spinning sensations.

What causes allergic reactions?

Allergies occur when the body’s immune system tries to defend the body from a particular substance as though it is harmful.

Most people who are affected by allergies usually have a family history of allergies or conditions that are closely related. It is not really understood why allergies affect people thought it could be the result of a cleaner, germ-free environment. This reduces the number of germs our immune system has to deal with, which may cause it to overreact when it comes into contact with harmless substances.

Does Phenergan cause any side effects?

Yes, like all medication it can cause a range of side effects. Below they are listed by rarity.

Stop taking and seek emergency help immediately if any of the following effects occur:

• Convulsions (seizures)
• Difficult or unusually fast breathing
• fast heart rate or irregular pulse
• high fever
• high or low (irregular) blood pressure
• increased sweating
• loss of bladder control
• severe muscle stiffness
• unusually pale skin
• unusual tiredness or weakness

The more common side effects may go away within a few days, however if they persist or worsen then please talk to your doctor. These side effects include:

• Drowsiness
• changes in blood pressure
• allergic skin reactions
• reduced platelet counts
• reduced white blood cell production
• breathing problems
• increased excitability
• abnormal movements

What is the recommended dosage of this treatment?

The recommended dosage for allergies (such as hayfever, rashes and hives) is:

• Children 2-5 years: Phenergan Elixir should be given to this age group.
• Children 5-10 years: a single 25mg tablet given at night. Do not give more than 25mg each day.
• Children over 10 years and adults: Start with one 25mg tablet taken at night, this may be increased to a maximum of one 25mg tablet twice a day.

For treatment and prevention of travel sickness:

• For children of 2-5 years: Phenergan elixir should be taken for this age group
• For children of 5-10 years: Phenergan elixir or Phenergan 10mg Tablets should be given to this age group.
• Children over 10 years and adults: a single 25mg tablet to be taken the night before the journey, this can be repeated after 6-8 hours if needed.

How should I store these tablets?

Always keep your tablets in their packs and store in a cool dry place where temperatures are below 30 degrees Celsius.

Do not store this or any other mediation in the bathroom or near a sink and always ensure to keep medication away from children and out of their reach.

Why do I need to fill in an online questionnaire to buy this product?

Some over the counter medicines are only allowed to be sold under the supervision of a pharmacist.

Just like when you buy this medicine in a high street or local pharmacy, the pharmacist will need to ask you a few questions. This is a legal requirement for selling this type of medicine.

You may not always realise when your local pharmacist asks you the required questions, as this can sometimes be done subtly. When sold online, we need to make sure our pharmacists have all the information they need to ensure this treatment is right for you.