The kind of thing that makes my head explode. Or, how not to take an antibiotic.

I just read a post by Don at Zap*Germs that reminded me of something I meant to write about a couple of weeks ago regarding antibiotic resistance. This is also the kind of thing that makes my head explode.

A friend of Mom's had a cold or a sinus infection or something, and her husband was also sick with something similar. Being too stubborn to go to the doctor, they continued to sniffle and carry on until their 20-something son remembered an antibiotic that he was prescribed a few months ago. Upon checking, they discovered that they still had the prescription bottle in the kitchen, so they called in a refill. (This is when pressure starts building up in my head, but it doesn't completely explode until I hear the next part of the story.)

The husband was the sickest of the two, but he was too stubborn to take the antibiotic unless his wife had some medicine too, so do you know what they did? They SPLIT the prescription and each took two pills of the five-pill course (it was a Z-pack, I think.) Gah! I don't know why they didn't break the fifth one in half, bringing each dose to 2 1/2 pills. I mean, it's the only logical thing to do.

Sheesh. It's not a good idea to expose microorganisms to random antimicrobials unless it's the minimum inhibitory concentration for the particular microbe that you're trying to inhibit or kill. The more they're in the presence of a dose that's less than inhibitory, the more likely it is that they'll develop some kind of resistance mechanism to that antimicrobial. It's like leaving the Jurassic Park velociraptors with the electric fence for a long time - it gave them a chance to figure out a way around it. Then, once a resistance mechanism has been developed by the microbe (like acquiring a gene that codes for an enzyme which breaks down the antimicrobial) it can helpfully share that information with another microbe by passing along a plasmid, and then they're both resistant. Yay!

Anyway, in conclusion, take ALL of an antibiotic that is prescribed for YOU, for an infection that you currently have, not one you had six months ago. It saves the head of your friendly neighborhood blogger from explosions. Thanks.