Key takeaways
Cephalexin (Keflex) and doxycycline hyclate (Vibramycin, Doryx) are both antibiotics used to treat bacterial infections, including respiratory tract infections and urinary tract infections (UTIs). However, they belong to different medication classes: cephalexin is a cephalosporin antibiotic, while doxycycline hyclate is a tetracycline antibiotic. Cephalexin is typically taken 2 to 4 times a day and is available in capsules, tablets, and liquid suspensions, whereas doxycycline hyclate is usually taken once or twice daily and comes in capsules, tablets, and liquid syrup. Cephalexin is only available as a lower-cost generic, while doxycycline hyclate is available as both generic and several brand names, such as Vibramycin and Doryx. Common side effects of cephalexin include nausea, vomiting, and diarrhea, while doxycycline hyclate can cause stomach upset, nausea, and sunburn. Doxycycline hyclate can interact with blood thinners and birth control pills, while cephalexin may interact with metformin and probenecid. Additionally, doxycycline hyclate is not safe for young children or pregnant women, whereas cephalexin is generally considered safe during pregnancy and breastfeeding.
