Key takeaways
Metronidazole (Flagyl) and doxycycline monohydrate (Monodox, Oracea) are both antibiotics, but they belong to different classes and treat different types of infections. Metronidazole is a nitroimidazole antibiotic that kills bacteria and parasites by damaging their genetic material, and it is used to treat infections like bacterial vaginosis, trichomoniasis, and amebiasis. Doxycycline monohydrate, on the other hand, is a tetracycline antibiotic that stops bacteria from multiplying by preventing them from making certain proteins. It treats a wide range of bacterial infections, including pneumonia, STIs like chlamydia, and severe acne. While both medications are available as lower-cost generics, metronidazole is typically taken multiple times a day and has a serious interaction with alcohol, whereas doxycycline monohydrate can make your skin more sensitive to sunlight and is not safe during pregnancy. Additionally, metronidazole can cause a metallic taste in your mouth, while doxycycline monohydrate can lead to tooth discoloration in children under 8 years old.
