Consumer Diary: Antihistamines May Help “Long COVID Patients,” Studies Show | Business


A friend of ours unfortunately has a case of “Long COVID”, also known as “Long Haul COVID”.

It’s a collection of various symptoms of the virus – sometimes all of them, sometimes just some – that can last unabated for months and months after you’ve contracted the affliction and the original infection has cleared up. Our friend suffers from debilitating headaches, incessant fatigue and eye problems.

Now there is hope for relief, according to a report published Feb. 7 in The Journal for Nurse Practitioners, which indicates that over-the-counter antihistamines taken for allergies can relieve symptoms.

The report describes two middle-aged women who caught COVID-19 in early 2020 and recovered.

Months later, the symptoms returned, including brain fog, rashes and bruises, chest pain, mouth ulcers, loss of taste and smell, and profound fatigue. About six months after her initial illness, the first patient ate cheese, to which she is allergic, and promptly took the over-the-counter antihistamine Benadryl (diphenhydramine). To his surprise, the long COVID symptoms subsided. The second patient had the same experience and took OTC Allegra (fexofenadine) for his seasonal allergies and then added Benadryl. Both now take antihistamines daily and say they are almost back to their pre-COVID state.

This report is supported by a major study, published October 5 in The Journal of Investigative Medicine, involving 49 long-term COVID patients. Of these patients, 26 took antihistamines and 19 had complete or partial relief of symptoms. Only six of the other 23, who were not taking antihistamines, saw their symptoms improve.

An article describing the two studies in the online magazine LiveScience suggests how immune cells – the “mast” cells – may be at the root of COVID’s long troubles. Mast cells release histamine – a defense chemical – when they detect a pathogen, such as a virus or bacteria, or a foreign substance. The chemical not only fights invaders, but it also triggers inflammation, swelling, allergic reactions and more. According to the National Cancer Institute, it may also act as a chemical messenger in the brain and increase heart rate and acid production in the stomach.

Mast cells “may go haywire in some patients following COVID-19 infection and trigger a flood of material,” the article says.

But antihistamines “could theoretically slow the flooding, as there is some evidence the drugs can help reduce mast cell activity,” hematologist Dr Lawrence Afrin said in the article, and so may be helpful in treating the long COVID.

However, you can’t generalize that they’ll work for everyone with long COVID, said Melissa Pinto, an associate professor of nursing at the University of California, Irvine, who authored the Feb. 7 report. “It shouldn’t be extrapolated because ‘it will help everyone,'” she said. On the contrary, she hopes for the point for further research.

On the other hand, “the great thing about antihistamines is that there are very few downsides” because the drugs are safe, cheap, and have few side effects, Dr. Paul Glynne, first author of the Journal of Investigative Medicine report. For most long-term COVID patients, “I don’t see a good reason not to start antihistamines,” he said.

Note: Long-term use of certain antihistamines has been linked to an increased risk of dementia, particularly in the elderly, the main reason I gave up my nightly use of over-the-counter generic Benadryl for decades to fight against insomnia.

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