Introduction
Acid suppression therapy is one of the most commonly prescribed medications worldwide. These medications include proton pump inhibitors (PPI) and Histamine-2 receptor antagonists (H2RA). They have been game-changing for treating people with gastroesophageal reflux disease (GORD) and peptic ulcers (1). Acidic stomach secretions with a pH level of 3 or lower can kill the bacteria, and thus guard the intestines against harm (2). Acid suppression therapy, while reducing stomach acid can be beneficial to patients with acid-related diseases, may also leave the gut vulnerable to some enteric infections (4, 5).
The coronavirus 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS CoV-2). COVID-19 has been continuously affecting populations worldwide, creating a global outbreak, since it was initially reported in China in December 2019 (6). COVID-19 related mortality rates vary widely among different populations, and risk factors are still being identified. Some of the confirmed risk factors include old age, chronic lung disease and smoking, cardiovascular disease, chronic kidney disease, diabetes mellitus and obesity, malignancy and chronic HIV infection (7). Use of various medications have also been described to increase the risk of COVID-19; nevertheless, these issues have not been ultimately confirmed.
COVID-19 can infect the GI system (8). Given the high expression of ACE2 receptor (the cellular receptor for SARS-CoV-2) in the intestinal epithelium, it is highly plausible that the gut is a site of active viral replication leading to GI involvement in COVID-19 (9, 10). This raises the possibility of increased susceptibility to and severity of COVID-19 infection among those using acid suppressant therapy.
Recently published observational studies highlight the various impacts of the use of acid suppressant therapy in COVID-19 infection (11-14). We review here the biological plausibility, the evidence and the recommendations that can be made for acid suppressant use in the present COVID-19 pandemic.