Antihistamines show promise in treating 'long COVID' symptoms

Antihistamines may provide relief for people suffering from symptoms of long COVID that impair daily functioning.
Posted at 9:07 AM, Feb 16, 2022
and last updated 2022-02-16 11:18:16-05

Antihistamines may provide relief for people suffering from symptoms of long COVID that impair daily functioning. That’s the conclusion of a case report on the experiences of two such patients co-authored by nursing scholars at the University of California-Irvine.

The effects of COVID on individuals range from mild symptoms to several weeks of illness to ailments including 'brain fog,' joint pain, exercise intolerance, and fatigue that last for months after the initial infection. The clinical term for these lingering long COVID effects is post-acute sequelae of SARS-CoV-2 (PASC), for which there is no standard treatment.

UCI said in a news release last week that the case report, recently published in The Journal for Nurse Practitioners, describes two healthy, active middle-aged women with PASC who found, by chance, that antihistamines led to greatly enhanced daily function, now sustained for almost a year.

Both took over-the-counter antihistamines to treat other conditions – the first one had triggered her dairy allergy by eating cheese, and the other had run out of the allergy medication she usually took – and experienced improved cognition and much less fatigue the next morning.

The first woman’s long COVID symptoms also included exercise intolerance, chest pain, headaches, a rash and bruising, while the second coped with joint and abdominal pain, as well as the rashes and lesions known as “COVID toes.”

In the first case, the woman didn’t take another antihistamine for 72 hours; when her symptoms reappeared, she took the medication and again found relief. With guidance from her primary healthcare provider, who prescribed her an antihistamine, she began a daily dosage that has significantly decreased her other long COVID symptoms. She reported that she has regained 90 percent of her pre-COVID-19 daily function.

In the second case, the woman took a different over-the-counter antihistamine as a substitute for what she had taken for years to manage her seasonal allergies. After noting that her long COVID-19 fatigue and cognition had improved, she continued to take it daily along with other allergy medicine. Her course of treatment, which now includes both over-the-counter medications, has also significantly reduced her additional long COVID-19 symptoms. She reported that she has regained 95 percent of her pre-illness functioning.

Previous studies, including those in the Journal of Investigative Medicine and Pulmonary Pharmacology & Therapeutics, have also shown the potential benefit of antihistamines as treatment for PASC.

People are urged to contact a healthcare provider if they have questions about their Covid treatment.