ALERT: dextromethorphan

Signal boosting siderea here:

Stop taking dextromethorphan now, it might make COVID-19 more dangerous.

siderea linked to the relevant article with "talk about burying the lede." The finding that dextromethorphan might be dangerous is after lots of "here's this thing we think might help, and that one..." and says that clinical testing is needed before you act on it. I agree with her that no, testing is not needed to stop taking dextromethorphan.

The original article says

Interestingly, a seventh compound – an ingredient commonly found in cough suppressants, called dextromethorphan – does the opposite: Its presence helps the virus. When our partners tested infected cells with this compound, the virus was able to replicate more easily, and more cells died.
Laboratory testing is excellent at generating leads but clinical trials must be done to know if these findings translate to the real world.

This is potentially a very important finding, but, and I cannot stress this enough, more tests are needed to determine if cough syrup with this ingredient should be avoided by someone who has COVID-19.

One thing it doesn't mention is that almost nobody needs dextromethorphan: it's used widely as an over-the-counter cough suppressant, but it doesn't work. It's no better than taking a placebo, and basically a waste of money. (I say "almost" because it has at least one other use, as an adjuvant in a combination pill with quinidine sulfate for pseudo-bulbar affect.)