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  • Sominex Tablets (Pack of 16)

Sominex Tablets (Pack of 16)

From £4.99

Medication features

  • Night time sleep aid
  • One a night tablets
  • Contains Promethazine Hydrochloride


About Sominex

Sominex contains the active ingredient promethazine hydrochloride, an antihistamine, that causes drowsiness and is commonly used for temporary sleeping difficulties.

You should not take sominex for more than 7 days in a row without consulting your GP. If you are struggling to reestablish your normal sleeping patterns, stop taking this medicine and seek advice from a doctor.

You should not take sominex with any other sleep aid medication as many of these products contain the same active ingredients which could potentially be harmful to you. It is advised that you speak to a doctor or pharmacist if you take any other medication before you start taking Sominex.

Sleeping difficulties

Poor sleep quality, finding it hard to fall asleep or maintaining sleep can be caused by many different factors such as daytime napping or stress.

This medication is used only for assisting with short term sleep problems caused by factors such as:

  • stress
  • jet lag
  • personal problems such as bereavement

Practical tips

  • It is very important to ensure ‘good sleep hygiene’, which is maintaining a regular bedtime routine. (this includes having a comfortable bedroom and removing objects that stimulate activity for example TVs, laptops, phones)
  • Having a hot shower or bath may also be helpful before bedtime. You could also try adding lavender oils in your bath.
  • Drink a warm, milky drink before bed.
  • Avoid caffeine in the evening.
  • Avoid heavy late night meals.
  • If possible, try to keep a sleep diary to pinpoint different factors that are influencing your sleeping pattern.
  • Regular exercise is important but not before going to sleep.
  • Relaxation techniques are also helpful in aiding sleeping difficulties.


Other treatments for temporary sleeping difficulties are available at Rightdose. these include:

  • Nytol original
  • Nytol herbal tablets
  • Nytol tablets one-a-night
  • Sominex herbal tablets


How do I take Sominex tablets? 

The recommended dose for individuals over 16 years old is 1 tablet with water, 30 minutes before you go to bed. Children should be supervised when using this product.

When should I use Sominex?

Sominex can be taken if you have had sleepless nights and sleeping difficulty, it acts as a temporary solution to help you get a restful night sleep. Sominex should only be taken when you can get a full night's rest and as such must be taken between 6 and 8 hours before you are required to wake up.

When should I not use Sominex?

Do NOT use Sominex if you:

  • Are allergic to any of the ingredients found in the medication.
  • Are under 16 years old.
  • Are pregnant.
  • Have had a stomach ulcer or have had an obstruction in your stomach or gut again.
  • Have had a recent head injury, concussion, dizziness, drowsiness or light-headedness
  • Have taken a medicine for depression called a monoamine oxidase inhibitor (MAOI) in the last 2 weeks
  • Can I use Sominex if I am pregnant or breastfeeding?
  • If you are breastfeeding, pregnant, think you be pregnant or are planning to become pregnant then it is advised that you speak to your Doctor before taking this medication.

Can I drink alcohol if I take Sominex?

No. Alcohol should be avoided during the course of treatment with Sominex.

Side Effects

All medication can have potential side effects, however, not all individuals will experience these.

Stop using this medicine immediately and see a doctor as soon as possible, if you have any of the following:

  • Allergic reactions (signs include: breathing difficulties, swelling of the mouth/skin, vomiting or stomach pain.)
  • Jaundice (signs include: yellowing of the skin and eyes).
  • Palpitations or abnormal heart rhythm.
  • Low blood pressure (signs include: dizziness and Lightheadedness).
  • Blurred, reduced vision or eye pain.
  • Listlessness and lack of energy.
  • Convulsions
  • Reduced white blood cells and platelets in the blood (signs include: easy bruising, high temperatures, ulcers in mouth/throat).

Other potential side effects include:

  • Drowsiness.
  • Dizziness.
  • Headache.
  • Clumsiness.
  • Shaking/trembling.
  • Stomach upsets.
  • Dry mouth.
  • Difficulty in passing urine.
  • Restlessness.
  • Disorientation.
  • Sensitivity to sunlight.

Info Leaflet

Before taking any medication, it is important to read the Patient Information Leaflet. You can find information leaflets for your medicines by typing them into the search bar at medicines.org, or by contacting us.


Directions for use

For individuals over 16 years old:

  • Take one tablet at bedtime.
  • It may be taken up to one hour after going to bed when you can't go to sleep.
  • Do not use this medicine for more than 7 days in a row. If your natural sleeping pattern does not return within 7 days or you continue to have episodes of sleeplessness talk to your doctor.


Do not use Sominex if you have:

  • An allergy to any of the ingredients in Sominex
  • An allergy to Phenothiazine drugs (for example chlorpromazine or pericyazine).
  • Had a concussion, lightheadedness, drowsiness, dizziness or any kind of recent head injury.
  • Taken MAOls (monoamine oxidase inhibitors) within the last 14 days.
  • If you still have sleeping difficulties after 7 days of using Sominex (you should speak to your doctor).
  • Drank alcohol.
  • Are under 16 years old.
  • Are pregnant.
  • Have had a stomach ulcer or have had an obstruction in your stomach or gut again.


active ingredient: promethazine hydrochloride 20mg

other ingredients: lactose, maize starch, croscarmellose sodium, magnesium stearate.

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