Provides detailed information on all sleeping pills & minor tranquillisers currently available in the UK.
Diphenhydramine is an antihistamine sometimes used as a sleeping pill.
It is an ingredient in some over-the-counter cold and flu medicines and sleep aids, under trade names such as Benylin, Nytol and Boots Sleapeaze.
You can find detailed information about this drug in the official Patient Information Leaflet (PIL). This includes information on what the medication is for, how to take it, possible side effects and safety information.
This leaflet should come with your medication, usually inside the box. Or you can download a PDF version of the PIL for your medication:
Some drugs come in different forms, such as tablets or liquid. There may be a separate PIL for each form of the drug, as well as for different doses. You should look at the PIL for the form and dose you have been prescribed.
You can also search these websites for your specific drug to find further information and PILs:
If you have any questions about your medication you can:
If you experience any side effects from your drug, you can report them to the MHRA via their Yellow Card scheme. This scheme allows the MHRA to collect information about which drugs cause which side effects and how common they are. This lets drug manufacturers give more accurate information about their medication.
Our pages on sleeping pills and minor tranquillisers have lots more information about this type of medication. This includes how they work, what they are prescribed for and what to know before taking them. It also covers their side effects and withdrawal effects.
These pages may also help:
This information was published in April 2021. We will revise it in 2024.
References and bibliography available on request.
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