Common side effects
Side effects promethazine Like all medicines, promethazine can cause side effects, although not everyone gets them.
Talk to your pharmacist or doctor if these side effects bother you or do not go away:
- feeling tired during the daytime
- feeling dizzy or unsteady on your feet, or having difficulty concentrating
Promethazine can sometimes make your skin more sensitive to sunlight. Keep out of direct or strong sunlight and follow sun safety advice.
If you’re over 65, you’re more likely to get side effects such as:
- feeling confused
- dry mouth
- blurred vision
- difficulty peeing
Talk to a doctor or call 111 straight away if you have these side effects.
Children are more likely to get side effects such as feeling restless or excited.
Serious side effects
Call your doctor straight away 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 notice more bruising or bleeding than normal
- you have muscle stiffness or shaking, or unusual face or tongue movements
Serious allergic reaction
In rare cases, it’s possible to have a serious allergic reaction (anaphylaxis) to promethazine.
Immediate action required:Call 999 or go to A&E now if:
- you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
- you’re wheezing
- you get tightness in the chest or throat
- you have trouble breathing or talking
- your mouth, face, lips, tongue or throat start swelling
You could be having a serious allergic reaction and may need immediate treatment in hospital.
These are not all the side effects of promethazine. For a full list, see the leaflet inside your medicine packet.