Who should not take Vibramycin?

Well, first off, if you've ever had an allergic reaction to Vibramycin, doxycycline, or any other tetracycline antibiotic (like minocycline), then definitely not for you. That's a hard stop. Pregnant women and breastfeeding moms? Generally, it's a no-go, or only if the benefits massively outweigh the risks, because it can mess with a baby's tooth and bone development. Same goes for young kids, usually those under 8 years old, because of the potential for permanent tooth discoloration and enamel problems. Also, folks with severe liver disease need a serious chat with their doctor before even thinking about it, and sometimes those with significant kidney issues too. It's not a candy, so these are the main groups that really need to avoid it or have a very careful discussion with their healthcare provider.