Don't stress solly
When I was taking antabuse I had to research all the stuff that contained alcohol, you would be surprised how many items out there have ethanol as an ingredient. Deodorant, mouthwash, skin creams, sauces, antiseptic cream, cleaning products..... as long as your not taking this particular medication or drinking the listerine with ice in a tall glass you will be fine. A mouthful won't even register in your brain that alcohol is present... although it might now that you know (power of the mind and all)
Swap it over to one without alcohol toot sweet if it stresses you out. But don't for a second think you have 'drank' or even 'consumed' alcohol. You are still going strong