Sniffing Astepro or Inhaling Heparin to Prevent or Calm COVID

Two inexpensive drugs are turning out to be surprisingly effective against COVID. One is the anticoagulant heparin. The other is an antihistamine nasal spray sold over the counter as Astepro (azelastine). Compare these inexpensive treatments to Paxlovid (nirmatrelvir + ritonavir). According to GoodRx, the retail price for this treatment is almost $1,800. With a GoodRx coupon, it’s only around $1500. Perhaps sniffing Astepro can prevent COVID. If someone catches COVID and develops lung problems, inhaling heparin might prevent complications. These old and affordable drugs might be worth discussing with a healthcare professional if the need arises.

Preventing COVID with an OTC Nasal Spray: Sniffing Astepro!

Have you caught COVID-19 once? How about twice or three times? According to the CDC more than three-fourths of Americans have caught COVID at least once. That means well over 200 million people in the United States have been infected by the SARS-CoV-2 virus. Even people who managed to avoid COVID until now are coming down with the latest variant.

That’s why we have been fascinated with the latest research about an over-the-counter antihistamine nasal spray called Astepro (azelastine). In the latest study, sniffing Astepro was surprisingly effective at preventing COVID. We wrote about this research in JAMA Internal Medicine (Sept. 2, 2025) at this link:

“Sniffing Out New Treatments for COVID (Azelastine) Offers Promise!”

The authors summed up their research findings this way:

“The findings of this randomized clinical trial suggest that azelastine nasal spray may reduce the incidence of respiratory infections caused by SARS-CoV-2. The established safety profile, over-the-counter availability, and ease of use of azelastine nasal spray support its potential as a practical, scalable on demand approach to preexposure prophylaxis, particularly in high-risk settings such as large gatherings or travel.”

You can read the details of the study at this link.

How Does Azelastine Work Against COVID?

This OTC antihistamine spray appears to block ACE2 receptors in the nose. It is these receptors that the SARS-CoV-2 virus binds to in order to get a foothold in the body. It’s possible that this drug, azelastine, also reduces transmission of rhinoviruses that cause colds.

The bottom line seems to be that sniffing Astepro can reduce the likelihood of catching COVID. So, if you are planning to travel or be in a large group of people, you might want to contemplate sniffing Astepro before departing.

Other Research Supporting Sniffing Astepro:

Lest you think that the recent research in JAMA Internal Medicine (Sept. 2, 2025) is the only investigation supporting the antihistamine azelastine, here are some other supporting studies:

On December 13, 2024, a study was published in the journal Viruses.

The authors describe the research this way:

“SARS-CoV-2 enters the respiratory tract via the nose and causes an infection through a series of events including binding to the nasal epithelial cells, entering the nasal epithelial cells via the host receptor angiotensin-converting enzyme-2 (ACE-2), undergoing local replication and transmission after entry, as well as causing the infection of ciliated cells in the upper respiratory tract… So as to prevent the progression of the disease at early infection phase wherein the viral load is highest in the nose and nasopharynx, the applicability of nasal spray with an active substance that inhibits virus entry and replication may stop or delay the progression of the disease to the lower respiratory system and reduce the transmission to uninfected individuals.”

The investigators used an azelastine nasal spray in patients who were newly infected with COVID.

Here were the conclusions:

“Overall, no incidence of COVID-19-related hospitalization, accompanied by significant reduction in viral load and improvements in symptom severity in this study support the use of azelastine 0.1% nasal spray in subjects tested positive for SARS-CoV-2 with mild symptoms.”

In other words, sniffing Astepro seemed to prevent COVID from doing a lot of damage. A reduced “virus load” after using the antihistamine seems to be a promising outcome.

Another study in the same journal, Viruses (Nov. 23, 2023) points out that the antihistamine azelastine has antiviral activity. The authors suggest that sniffing azelastine (Astepro) might protect against SARS-CoV-2 variants, RSV infection and influenza viruses.

Of course, much more research needs to be conducted before we can say with certainty that sniffing Astepro will protect you from viral infections. On the other hand, if you are venturing into enemy territory (where people are likely to be spreading colds, flu or COVID), sniffing and masking might not be such a bad preventive strategy.

The Heparin Story Is Intriguing:

The Food and Drug Administration first approved the anticoagulant heparin in 1939. It was originally used to prevent blood clots. Doctors still use heparin today to prevent such clots from expanding.

Surgeons sometimes use heparin during an operation to prevent blood clots. For example, if a cardiac surgeon needs to put a patient on a heart-lung machine, heparin can be used to keep blood clots from developing.

A new study of COVID patients demonstrates that heparin can prevent severe complications from SARS-CoV-2 (eClinical Medicine, Sept. 27, 2025).

Here is how the investigators introduce their heparin research:

“Inhaled nebulised unfractionated heparin (UFH) has a strong rationale as a treatment for severe respiratory infections, including COVID-19, due to its antiviral, anti-inflammatory, and anti-coagulant properties, which may prevent viral entry, lung injury progression, and pulmonary thrombosis. We aimed to evaluate the efficacy of inhaled nebulised UFH to prevent intubation or death in hospitalised COVID-19 patients.”

Did you appreciate the significance of these words?

“Antiviral, anti-inflammatory and anti-coagulant”

Such capabilities are extraordinary for one medication. Add to those crucial biological actions against COVID-19 one more benefit:

an anti-cancer potential!

 An article in the journal Discover Oncology, Feb. 24, 2025 offered the following:

“Heparin, traditionally known for its anticoagulant properties, has recently been identified as a potential agent in cancer therapy. Its derivatives, including low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH), are being investigated for their multifaceted roles in oncology.

“Currently, heparin serves not only as an anticoagulant but also finds applications in respiratory diseases, inflammation, and even antimicrobial treatment…In recent years, growing evidence has indicated heparin’s potential anticancer effects, which extend beyond its anticoagulant properties. Studies have suggested that heparin can inhibit cancer metastasis, tumor growth, and angiogenesis.”

 Inhaling Heparin Against COVID Complications:

You just read how sniffing Astepro, the antihistamine azelastine, might protect against or lessen COVID symptoms. In the study of hospitalized COVID patients, 238 people with COVID were assigned to receive inhaled heparin. Another 215 received standard of care and 25 got placebo.

In-hospital death was far higher in the control group. Administering heparin in inhaled form apparently prevented lung injury and blood clots in the lungs. The researchers suspect that heparin could be beneficial against other serious lung infections, such as pneumonia or influenza. Of course, inhaled heparin can only be done in a hospital setting with careful monitoring. Nevertheless, this old drug may have new uses against both COVID and cancer.

Final Words:

We have been fascinated with the idea of repurposing old drugs for new uses. There can be lots of benefits.

1. The medications are almost always available at low cost compared to new drugs.
2. We have lots of experience with such medicines, especially when it comes to side effects.
3. Old drugs have jumped through FDA hoops and don’t require new testing.
4. Doctors can prescribe old drugs for new purposes without FDA approval.

If you would like to learn more about repurposed drugs, here are some links you will find helpful:

Show 1328: Teaching Old Drugs New Tricks

Show 1401: Are Miracle Cures Hiding in Plain Sight? Unlocking the Lifesaving Potential of Old Drugs

There are cautions, however. Here is an article I wrote a few years ago warning about the downside of off-label prescribing:

Teaching Old Drugs New Tricks Is Risky

Whether it’s sniffing Astepro against COVID-19, taking a beta blocker such as metoprolol for performance anxiety or taking gabapentin for pain, it is important for people to know the pros and cons of repurposed medicines. Doctors should always let patients know if they are prescribing a medicine “off label.”

If you found this article about azelastine and heparin interesting, we would grateful if you would pass it along to friends and family. We fear that COVID-19 will be with us for a long time to come. Having an easy-to-use OTC antihistamine available as a potential protector might be helpful, don’t you think?