Could Pepcid help people with COVID-19?
As mentioned earlier in this issue of TreatmentUpdate, doctors are repurposing many medicines to find ones that have potential for preventing and treating COVID-19. One such medicine is the anti-ulcer/antacid drug famotidine. It is sold under the brand name Pepcid and is also available in generic formulations. Doctors became interested in this drug when they reviewed medical records of more than 6,000 people with COVID-19 in Wuhan, China. The doctors found that many people had been taking famotidine prior to developing COVID-19 (because of excess stomach acid) and during this infection. An analysis of these patients revealed that 14% of people taking famotidine died after developing COVID-19 vs. 27% of people not taking famotidine. However, such findings are merely suggestive, not definitive.
Spurred by the findings in Wuhan, doctors at the Columbia University Medical Center in New York reviewed the health records of 1,620 people hospitalized with COVID-19. They also found a suggestion that famotidine may be beneficial.
Scientists are not certain how or why famotidine might be helpful in people with COVID-19. It does not appear to have antiviral activity against coronaviruses or any enzymes used by SARS-CoV-2. It is possible that famotidine has an effect(s) on the immune system. The suggested immunological mode of action of famotidine is extremely complex and beyond the scope of this article. However, it is plausible that famotidine ultimately is able to reduce inflammation in the lungs—a hallmark of severe COVID-19. Clinical trials with this drug in people with COVID-19 are underway and will hopefully shed light on how famotidine might work.
We now report details of 10 people who took famotidine after becoming infected with SARS-CoV-2 and who were monitored by their doctors. Although the findings from these 10 people are at best anecdotal and cannot be used to justify the use of famotidine outside of clinical trials, they are nonetheless interesting.
Case reports
Participants ranged in age from their 20s to their 70s. There were six men and four women. Four people had underlying conditions, mostly some form of cardiovascular disease. None were hospitalized. Participants initiated famotidine when they developed symptoms of COVID-19.
Most participants (70%) were diagnosed with SARS-CoV-2 infection via virus detected from nasal swabs. Two others were found to have antibodies to the virus and one was diagnosed solely on the basis of their symptoms.
The most commonly used dose of famotidine was 80 mg three times daily, taken orally. Half of the participants took famotidine for between five and 11 days and the other half for up to 21 days.
Results
None of the participants required hospitalization. They reported feeling some improvement in symptoms beginning 24 hours after taking their first dose of the drug. Subsequently, symptoms continued to decrease such that 14 days after initiating famotidine they had resolved.
Three participants reported adverse events as follows:
- one person – mild dizziness and occasional “racing heart beats”
- one person – mild dizziness, dry skin and sleeping problems
- one person – mild, unspecified “gastrointestinal symptoms” and temporary forgetfulness
The doctors who monitored these patients noted that with the exception of temporary forgetfulness, all the other adverse events were probably famotidine-related side effects. The doctors also stated that “all side effects resolved on discontinuation of famotidine.”
Bear in mind
This report on 10 people is intriguing. However, definitive answers about famotidine’s potential impact on the course of COVID-19 will hopefully emerge from ongoing randomized clinical trials.
—Sean R. Hosein
REFERENCES:
- Janowitz T, Gablenz E, Pattinson D, et al. Famotidine use and quantitative symptom tracking for COVID-19 in non-hospitalised patients: a case series. Gut. 2020; in press.
- Borrell B. New York clinical trial quietly tests heartburn remedy against coronavirus. Science. 26 April 2020.
- Malone RW, Tisdall P, Fremont-Smith P, et al. COVID-19: famotidine, histamine, mast cells and mechanisms. Preprint. 2020.