Diphenhydramine
Diphenhydramine or diphenhydramine hydrochloride is a commonly used antihistamine, which is also used for coughs, to aid sleep, for certain symptoms of Parkinson's diease, as well as for allergy symptoms, bites, itching and eczema.[1][2] Diphenhydramine is the active ingredient in Benadryl, which is sometimes used as a sleep aid as well as an anti-histamine.[1]
Contents
Additional active ingredients[edit | edit source]
Products containing diphenhydramine often contain other ingredients, for example:
- acetaminophen (paracetamol) for night-time pain relief
- expectorants like guaifenesin, or dextromethorphan hydrobromide in cough products[3]
- levopenthol, a decongestant and pain reliever[3][4]
Other common ingredients include:
- ethyl (a form of alcohol) especially in cough syrups
- food colorings, especially reds and blues[3]
Brand names[edit | edit source]
Diphenhydramine is marketed under many different brand names including:
- Allermax
- Banophen
- Benadryl
- Benylin Chesty Coughs Original and Benylin Mucus Cough Nights (syrup)
- Compoz Nighttime Sleep Aid
- Covonia Nighttime Forumla
- Diphedryl or Diphenhis
- Nytol One-A-Night
- Nytol QuickCaps
- QlearQuil Nightitme Allergy Relief
- Siladryl Allergy
- Silphen Cough
- Sominex original
- Tranquil
- Twilite
- Vanamine PD
- Unisom Sleepgels maximum strength
- Z-Sleep
- ZzzQuil[1][5][6]
Theory[edit | edit source]
Evidence[edit | edit source]
Dosage[edit | edit source]
The usual dose suggested is:
- creams for bites, itches or eczema - apply a thin layer once or twice a day
- allergies and hayfever, itching or as an anti-histamine - 25mg to 25mg, 3 or 4 times a day
- cough and cold symptoms – diphenhydramine is typically mixed with other medicines, the dose depends on the medicine
- creams for bites, itches or eczema - apply a thin layer once or twice a day
- sleep problems or insomnia - 25mg to 50mg[2]
Risks and safety[edit | edit source]
Diphenhydramine has a wide range of side effects include dizziness and drowsiness.[1]
It is described as non-addictive/not habit forming, but recently concerns have been raised about long term use including the reduced effectiveness in the long term, causing people to increase the dose.[7] Theoharides and Stewart (2016) stated that in high risk over 65s taking 50mg for 3 years or 50mg for 3 years was associated with cognitive dysfunction.[7]
Using a product containing diphenhydramine marketed for nighttime pain, coughs or cold and flu also involves the side effects of other active ingredients, or from inactive ingredients such as food colorings.[3][6]
Costs and availability[edit | edit source]
Diphenhydramine is available over the counter, under many different brand names including Benadryl.[1] Diphenhydramine is available in tablet, capsule or syrup/liquid form, and in anti-histamine products as a cream, spray or ointment to be applied to the skin.[8]
In the UK, diphenhydramine is a pharmacy-only medication and is not given on prescription.[3] Diphenhydramine is available under the brand names Benylin Chesty Coughs, Histergan, and Nytol Once-A-Day.[2]
See also[edit | edit source]
Learn more[edit | edit source]
- Diphenhydramine - drugs.com
- Diphenhydramine - NHS
- Diphenhydramine - WedMD
References[edit | edit source]
- ↑ 1.01.11.21.31.4 "Diphenhydramine Uses, Dosage & Side Effects". Drugs.com. Retrieved Nov 9, 2020.
- ↑ 2.02.12.2 "Diphenhydramine (including Nytol Original & Histergan): drowsy antihistamine". National Health Service. Sep 21, 2018. Retrieved Feb 14, 2021.
- ↑ 3.03.13.23.33.4 "Electronic Medicines Compendium". www.medicines.org.uk. Retrieved Feb 13, 2021.
- ↑ "Levomenthol". Drugs.com. Retrieved Feb 13, 2021.
- ↑ "£8.59 - Benylin Chesty Coughs Original 300ml". Weldricks Pharmacy. Retrieved Feb 12, 2021.
- ↑ 6.06.1 "Covonia Night Time Formula - Summary of Product Characteristics (SmPC)". www.medicines.org.uk. Retrieved Feb 13, 2021.
- ↑ 7.07.1 Theoharides, TC; Stewart, JM (2016). "Antihistamine and mental status" (PDF). J Clin Psychopharmacol. 36 (3): 195–7.
- ↑ "Diphenhydramine Oral: Uses, Side Effects, Interactions, Pictures, Warnings & Dosing". www.webmd.com. Retrieved Feb 13, 2021.
expectorant - An antitussive is a cough suppressant, an expectorant is a cough suppressant that helps someone discharge or cough up mucus.
α - Greek letter alpha or alfa (symbol)
adverse reaction - Any unintended or unwanted response to the treatment under investigation in a clinical trial.
The information provided at this site is not intended to diagnose or treat any illness.
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