Over the past 6 months, pharmacists have been inundated with questions about the use of supplements, OTC medications, and prescription drugs in the battle against the SARS-Cov-2 virus that causes COVID-19. While the best evidence continues to support three behaviors as the most effective methods of reducing risk—maintaining a physical distance of 6 feet, wearing a mask, and washing hands frequently and thoroughly—some research indicates that certain supplements and common OTC medications could reduce the risk of infection or mitigate the seriousness of symptoms.
The Eastern Virginia Medical School (EVMS) and other healthcare organizations have incorporated a mix of readily available agents into their management protocol for COVID-19, while acknowledging that “there is very limited data (and none specific for COVID-19)” for the combinations.
For prophylaxis, the medical school recommends vitamin C (500 mg) and quercetin (250 mg-500 mg twice a day) with zinc (75 mg-100 mg per day), melatonin (0.3 mg-2 mg) each night, and vitamin D3 (1,000-4,000 IU per day). Famotidine (20 mg-40 mg per day) may be added to the mix. For patients with mild symptoms, EVMS recommends the same combination, with optional additions of ivermectin (150 ug-200 ug per kg as a single dose), and one low-dose or regular aspirin per day.
What’s the thinking behind recommending these supplements and medications?
Vitamin C is critical to the proper functioning of immune cells. It’s also a powerful antioxidant that protects the body from the oxidative stress caused by free radicals, which are associated with a number of diseases. Vitamin C has been used for years to reduce the symptoms of colds, about one-quarter of which are caused by other coronaviruses, and a meta-analysis of studies that enrolled more than 11,000 patients showed that it also reduced the risk of contracting colds. Perhaps the most direct evidence for vitamin C’s use in COVID-19 is a study published this February demonstrating that it reduced symptoms in patients with sepsis and acute respiratory distress syndrome caused by other viruses.
Quercetin has shown preclinical benefit as an antiviral medication, and a Chinese study found that it bound with the spike protein in the novel coronavirus, reducing its ability to infect cells. Like vitamin C, it has antioxidant effects. On the downside, it has not shown significant stability or potency in in vitro experiments.
Zinc is essential for immune-cell development, and some studies have found that it reduces the risk of contracting respiratory infections. It may also reduce the number of days that someone has a cold or other respiratory tract infection. About 30% of American adults are deficient in the mineral, so taking a moderate dose of the supplement may be helpful anyway.
Melatonin is best known and most commonly used to boost sleep and reduce anxiety, both of which improve the immune system. It also blocks inflammasome activity, reducing inflammation in the lungs, and it reduces the risk of fibrosis, one of the most challenging complications for patients who have had COVID-19.
Evidence for vitamin D3 is mixed. On the one hand, several studies early in the pandemic found that countries with populations that had low levels of vitamin D on average were more likely to have serious outbreaks and higher mortality rates. Other observational studies found that individuals with vitamin D deficiency were more likely to be hospitalized in the U.S., but confounding factors could explain some of the difference as well.
In the U.S. studies, low levels of vitamin D were associated with patients who lived in nursing homes and with African American patients. Both groups also had other notable risk factors for COVID-19. “Vitamin D deficiency has also been implicated in asthma and other respiratory disorders,” according to Thomas Carpenter, MD, an endocrinologist at Yale Medicine, so it might be helpful. Excess vitamin D, however, might overstimulate the immune system, which could be damaging in COVID-19. In addition, too much vitamin D can be toxic to the heart and kidneys.
Famotidine is available OTC as Pepcid and as you’ve likely experienced, it has been in short supply in many parts of the country since an April news report stated that it reduced the risk of death or ventilator use in patients hospitalized with COVID-19. A subsequent case series published in June found that 10 people who managed the disease at home improved within a couple of days of taking famotidine. Results of a large clinical trialin hospitalized patients have not yet been published, and exactly why the drug would work remains unclear.
Aspirin reduces the symptoms of fever and aches associated with COVID-19. It may also reduce the risk of blot clots, which have emerged as a serious problem in COVID-19. Up to 70% of patients hospitalized with the novel coronavirus experience hypercoagulability, and about 25% of patients admitted to the ICU with the disease develop pulmonary embolisms. A growing number of reports indicate that stroke is a common—and sometimes presenting—symptom of COVID-19.
Consequently, many hospitals put all patients admitted with the disease on a blood thinner. That doesn’t mean that everyone who develops symptoms should take aspirin, however. Children and adolescents should avoid aspirin because of the risk of Reye’s syndrome, and patients with bleeding issues should not take it either.
The antiparasitic ivermectin requires a prescription.
Any patients who believe they have COVID-19 should be tested and consult with their primary care provider on the next steps for their care, if they test positive.