Brief summary: Still too soon for antibody testing and no Pepcid (famotidine) available because it is being studied as a possible COVID 19 treatment.
The last few weeks have seen the availability of many new tests for antibodies to COVID 19, most of which, have not been adequately tested for accuracy. Many of you have asked about whether to get tested. The answer is still not yet, for the following three reasons:
(1) Only a few percent of people in Contra Costa County have positive antibodies. Even among very high risk patients with symptoms suggestive of active disease, only 7% of PCR tests were positive. Recent studies in Santa Clara and Los Angeles Counties showed about a 3% positive rate. Our county has much lower rates.
(2) The antibody tests may not be accurate enough. Most tests have a false positive rate of a few percent. That is, for every 100 people tested 2-3 positive tests would be false positives. If the rate of antibody positivity is only several percent, a test of 100 people would yield 5-6 positive tests, with 50% being false positive. If your test came back positive, you would have no way of knowing whether it was a true of false positive result.
(3) Even if you knew that you were a true positive, it would not have any actionable consequence because at this point we do not know if those with COVID 19 antibodies can be reinfected. Thus, you would still have to adhere to all social distancing recommendations.
At present, the only role for COVID 19 antibody testing is for determining how many people have been infected at the population level. It does not yet provide accurate or meaningful results for an individual. So, I ask your patience to wait a bit longer.
Here are some recent New York Times articles on the topic:
https://www.nytimes.com/article/antibody-test-coronavirus.html?referringSource=articleShare
https://www.nytimes.com/2020/05/03/world/europe/coronavirus-antibodies-italy.html
Also, in our topsy turvy world of coronavirus, nothing is certain, not even stomach acid pills!
On Sunday night April 26, 2020, Science News released on online report of an ongoing drug trial in New York, using high dose intravenous famotidine as a possible treatment for COVID 19 illness. https://www.sciencemag.org/news/2020/04/new-york-clinical-trial-quietly-tests-heartburn-remedy-against-coronavirus
Within twenty-four hours almost all available stock of Pepcid (famotidine) had been sold out, an illustration of both the rapid-fire news cycle and the degree of panic around the COVID 19 virus. Many of you take Pepcid (famotidine) as treatment for digestive tract illness and may have difficulty finding additional supply of the drug in the near term. Unfortunately, a similar drug Zantac (ranitidine) has already been removed from the market due to possible carcinogenic contaminants in the manufacturing process.
If you run out of Pepcid (famotidine), you may need to use Prilosec (omeprazole), which is also available without a prescription. Prilosec (omeprazole) is proton-pump inhibitor, which is a different category of medication than Pepcid (famotidine) which is a H2 blocker and has a higher risk of side effects in the long run. However, you will only need to use it as a temporary substitution.
Please contact me with any questions or concerns.
Thank you,
Barry Rotman MD