Side Effects Of Promethazine

Like all medicines, promethazine can cause side effects, although not everyone gets them.

Children are more likely to get side effects such as feeling restless or excited.

Common side effects of promethazine

There are things you can do to help cope with these side effects of promethazine:

Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.

Serious side effects

Call your doctor or call 111 straight away if:

• you're feeling confused - you're unable to concentrate or think clearly, or have muddled thoughts
• you have blurred vision
• you have difficulty peeing

Call your doctor or call 111 straight away and stop taking promethazine if:

• the whites of your eyes or your skin turn yellow, although this may be less obvious on black or brown skin - these can be signs of liver problems
• you are bruising or bleeding more than normal
• you have muscle stiffness or shaking, or unusual face or tongue movements
• you have a fast, pounding or irregular heartbeat (palpitations)
• your child becomes aggressive, sees or hears things that are not there (hallucinations) and becomes hyperactive

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to promethazine.

Call 999 now if:

• your lips, mouth, throat or tongue suddenly become swollen
• you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
• your throat feels tight or you're struggling to swallow
• your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
• you suddenly become very confused, drowsy or dizzy
• someone faints and cannot be woken up
• a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)

You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.

These can be signs of a serious allergic reaction and may need immediate treatment in hospital.

Other side effects

Promethazine can sometimes make your skin more sensitive to sunlight. Keep out of direct or strong sunlight while you're taking it and follow sun safety advice.

These are not all the side effects of promethazine. For a full list, see the leaflet inside your medicine packet.

Reporting side effects

You can report any suspected side effect using the Yellow Card safety scheme.

Visit the Yellow Card website for more information about reporting side effects.

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