AZELASTINE NASAL SPRAY

What is azelastine?

Azelastine is an over-the-counter antihistamine nasal spray for seasonal or year-long allergy symptoms such as nasal congestion, a runny nose, sneezing, itching, and post-nasal drip. It can be given as one or two sprays in each nostril twice a day and is a suitable antihistamine option with fewer side effects compared to oral antihistamines.

How can azelastine help alleviate certain long COVID symptoms?

Histamine is a chemical our immune system releases that causes our allergy symptoms. Cells in our body called mast cells release histamine, and in some patients after COVID, they may release too much, leading to some of the symptoms of long COVID. Two types of drugs can block histamine in the body, which we call our H1- and H2-antihistamines. Azelastine is an example of an H1-antihistamine that has also been found to bind to the ACE-2 and sigma-1 receptors in the nasal epithelium.^1,2 This may inhibit the SARS-CoV-2 virus from binding to ACE-2 and replicating intracellularly. As an antihistamine, azelastine’s anti-inflammatory properties can also aid in relieving nasal symptoms of long COVID.

What evidence supports azelastine’s use for long COVID?

In several studies, Azelastine has shown antiviral activity against COVID in vitro and a more significant reduction in viral load compared to placebo.²  Intranasal azelastine has also demonstrated a faster decline in symptom severity compared to placebo in COVID patients.³ While antihistamines as a whole have been extensively studied for long COVID symptoms, there is a lack of studies specifically evaluating the use of azelastine post-COVID. Therefore, azelastine may not be as effective for long COVID symptoms compared to oral H1-antihistamines such as fexofenadine.

What should you be aware of when taking azelastine?

Azelastine nasal spray may cause nasal irritation, sore throat, headache, or drowsiness. Some may also complain that it has a bitter aftertaste.

References:

1)      Mashauri HL. Covid-19 Histamine theory: Why antihistamines should be incorporated as the basic component in Covid-19 management? Health Sci Rep. 2023 Feb 7;6(2):e1109. doi: 10.1002/hsr2.1109

2)      Klussmann JP, Grosheva M, Meiser P, Lehmann C, Nagy E, Szijártó V, Nagy G, Konrat R, Flegel M, Holzer F, Groß D, Steinmetz C, Scherer B, Gruell H, Schlotz M, Klein F, de Aragão PA, Morr H, Al Saleh H, Bilstein A, Russo B, Müller-Scholtz S, Acikel C, Sahin H, Werkhäuser N, Allekotte S, Mösges R. Early intervention with azelastine nasal spray may reduce viral load in SARS-CoV-2 infected patients. Sci Rep. 2023 Apr 26;13(1):6839. doi: 10.1038/s41598-023-32546-z

3)      Dings C, Meiser P, Holzer F, Flegel M, Selzer D, Nagy E, Mösges R, Klussmann JP, Lehr T. Pharmacometric Modeling of the Impact of Azelastine Nasal Spray on SARS-CoV-2 Viral Load and Related Symptoms in COVID-19 Patients. Pharmaceutics. 2022 Sep 27;14(10):2059. doi: 10.3390/pharmaceutics14102059