Researchers are investigating whether medication used to treat people with reflux disease could also help people with the coronavirus. While other studies suggest reflux drugs may double the risk of diagnosing positive for Covid-19.
Let’s take a look at the latest studies.
Famotidine has been linked to improved symptoms in patients with Covid-19, including cough, shortness of breath, fatigue, headaches and anosmia.
What is famotidine?
Famotidine belongs to a group of medicines known as histamine H2-receptor antagonists or H2-blockers.
These block the action of histamine in the stomach to decrease the production of stomach acid. Famotidine is known by the brand name Pepcid in the UK and the US.
A small US study has monitored the use of famotidine in a group of 10 patients with Covid-19 and found that patients reported marked improvements of disease related after starting the medication.
Researchers concluded that high-dose oral famotidine is ‘well tolerated and associated with improved patient-reported outcomes in non-hospitalised patients with Covid-19’.
All patients noticed a rapid improvement in their condition within 24 to 48 hours of starting famotidine.
The study has been published in this month’s medical journal Gut.
According to the US research team, it was inspired to explore famotidine’s potential after doctors who worked with coronavirus patients in Wuhan, China discovered that although one in five Covid-19 patients over the age of 80 died, many of those who survived had been taking famotidine.
Why would this medication work?
Some researchers say that histamine release may contribute to the inflammation associated with Covid-19 infection. Viruses activate mast cells – widely distributed in the gastrointestinal tract – that release early inflammatory chemical compounds, such as histamine and protease.
The study explains: “Mechanistically, famotidine could have a viral target, for example, one of the viral proteases, or a host target, resulting, for example, in modulation of the immunological response to the virus.”
So, does this mean Pepcid can stop the coronavirus?
It is important to remember that these studies are very small. The US study warns that while its findings suggest that famotidine may affect the course of Covid-19, they must be considered in the context of several limitations.
Placebo effect, enrolment bias and recall bias for symptoms may affect findings. There also remains the possibility that changes may reflect treatment independent convalescence, as the natural course of Covid-19 in patients who do not require hospital admission is not well known.
Study co-author Dr Kevin Tracey has also warned it is still to early to make firm conclusions, according to a report by CNN.
Dr Tracey told the US news publication that ‘patients in the study are in the hospital taking mega-doses intravenously – about nine times what someone would normally take for heartburn’ and warned that people ‘should not go to the drugstore and take a bunch of heartburn medicine.’
I thought H2-receptors were dangerous anyway?
Last year, drug companies recalled the H2 blocker ranitidine after the cancer-causing chemical N-nitrosodimethylamine (NDMA) was spotted in versions of the medication.
However, none of the other H2 blockers – including famotidine – have been found unsafe.
PPIs causing positive Covid-19 tests
According to a study published in the American Journal of Gastroenterology, usage of proton pump inhibitors (PPIs), in particular twice-daily dosing, have been correlated with increased odds for reporting a positive Covid-19 test.
The US study found that use of PPIs does not lead to an increase of Covid-19 symptoms but proposed that PPI-induced hypochlorhydria can impair the body’s proximal defence against ingested bacteria and viruses.
So, is reflux connected to coronavirus?
Another study in China, found that laryngopharyngeal reflux disease (LPR) ‘commonly prevalent in hospitalised patients with Covid‐19 and independently associated with risk of severe or critical infection’.
However, in response to the study other experts said ‘many points have to be addressed regarding the methodology and the conclusion of the study. In an article, it was suggested that any study into reflux and Covid-19 should involve a non-invasive objective approach, such as pepsin saliva detection.
Professor Peter Dettmar says: “Both these studies are very small and largely observational so it would be far too early to make any conclusions from them. Larger, controlled studies that involved other related medication would be needed to confirm how and if they can change the course of Covid-19, along with the determination of salivary pepsin in Covid-19 patients as a biomarker for reflux disease”.
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