Picture this. She wakes up early in the morning. It is the 25th day of May – the day she takes her monthly osteoporosis medication, Fosamax.
Bleery-eyed, she stumbles into the bathroom and retrieves the pill from her medicine cabinet, rips it from its shrink wrapped cardboard and gulps it down with a glass of water. Satisfied she was done with that for another month, she starts her day, feeling strangely energized.
Two hours later, as she straightens up the bathroom, she finds an empty wrapper for her hearing aid battery on the sink beside her water glass. 
Jumping jitters! She has swallowed her hearing aid battery instead of the pill! She rushes to the phone to call her doctor, thinking surgery might be in order. He tells her not to worry, it wouldn’t break down and metabolize, and all would be fine in a few days.
This is a true story. It happened to a friend of mine and we’ve gotten many a good laugh out of that episode. Don’t let this happen to you. You might want to store your batteries in your tool box instead of the medicine cabinet.
I had a similar experience. I was visiting my brother and sister a few years ago. I arose early the morning after arrival and stumbled downstairs to the bathroom. Pre coffee and pre contact lenses, I reached into my makeup bag for my toothbrush and toothpaste and proceeded to brush my teeth. I thought “Boy, this toothpaste tastes funky this morning.” Upon closer inspection, I had grabbed a tube of Vagisil instead of the toothpaste! My brother and sister both got a good laugh out of that and I learned to put my contacts in before attempting my morning ablutions!
Oh my goodness. But do your teeth still itch?