Five things to know about antihistamines

Antihistamines are one of the most widely taken medications worldwide, used to relieve allergy symptoms such as runny noses, sneezing and congestion.

But new research points out that misconceptions around these common medications abound, leading to both misuse and overuse.

A paper published in the Canadian Medical Association Journal lists five facts to know about them:

1. Antihistamines are widely misused. They can relieve symptoms of hay fever and outbreaks of hives, but aren’t useful for asthma, eczema, coughs or insomnia.
2. Older antihistamines, referred to as “first-generation antihistamines”, have negative side effects and can be dangerous for both older and younger people. Treatments containing diphenhydramine, chlorpheniramine or hydroxyzine can cause drowsiness and affect cognitive functions. Overdosing can be fatal.
3. Newer antihistamines are as effective as first-generation medications, while being safer and causing fewer side effects. They should still not be taken with alcohol, though.
4. Antihistamines are not a substitute for epinephrine when treating anaphylaxis. They may be used in conjunction with epinephrine injections, but shouldn’t be used instead.
5. Most antihistamines can be used safely during pregnancy and breastfeeding at standard doses. They’re also usually safe for children to use.

“People need to rethink what they stock in their home cabinets as allergy medicines, what hospitals keep on formulary, and what policymakers recommend,” says Derek Chu, a researcher in allergies at McMaster University in Canada and co-author on the paper.

“There are new modern second-generation antihistamines that are potent, specific, fast acting and of proven safety which everyone should be using to treat allergic rhinitis and hives,” adds Gordon Sussman, a professor of medicine at the University of Toronto in Canada and co-author on the paper.

More information can be found on HealthDirect and NPS Medicinewise.

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