Posted by: Denise | 2020/02/23


Long-term side effects of allergex usage

I have been taking an Allegex tablet every night for years, to assist me in falling  asleep. will there be any long term side affects or will affect me daily well being now I'm just wondering how long i can take allegex as i have been taking it for a long time, as a sleep aid.

Expert's Reply


Allergy expert
- 2020/03/05

Allergen (chlorpenamine) is one of the older generation "anticholinergic" sedating antihistamines. Hence it helps you fall asleep. Unfortunately there have been some reports in the medical media suggesting that these older sedating antihistamines can cause dementia and Alzheimers Disease if used for prolonged periods.

Antihistamines with anticholinergic properties include the following:

·       Chlorpheniramine

·       Cyproheptadine

·       Doxylamine

·       Hydroxyzine

·       Dimenhydrinate

·       Diphenhydramine

·       Meclizine

·       Promethazine


Original Investigation 

June 24, 2019

Anticholinergic Drug Exposure and the Risk of DementiaA Nested Case-Control Study

Carol A. C. Coupland, PhD1Trevor Hill, MSc1Tom Dening, MD2; et alRichard Morriss, MD2Michael Moore, MSc3Julia Hippisley-Cox, MD1,4

Author Affiliations Article Information

JAMA Intern Med. 2019;179(8):1084-1093. doi:10.1001/jamainternmed.2019.0677


The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.

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