Key takeaways
Cephalexin (Keflex) and penicillin V potassium (Penicillin VK) are both antibiotics used to treat bacterial infections, but they belong to different medication classes. Cephalexin is a cephalosporin antibiotic, while penicillin V potassium is a penicillin antibiotic. Both medications can treat respiratory and skin infections, but cephalexin is also used for urinary tract infections (UTIs) and bone infections, while penicillin V potassium is used for strep throat and to prevent rheumatic fever. Cephalexin is typically taken 2 to 4 times a day, whereas penicillin V potassium is taken 3 to 4 times a day. Cephalexin is available as a generic in capsules, tablets, and liquid forms, while penicillin V potassium is available as a generic in tablets and suspension. Common side effects for both include nausea, vomiting, and diarrhea, but cephalexin can also cause dizziness and fatigue. Cephalexin may interact with metformin and probenecid, while penicillin V potassium should not be taken with other antibiotics unless prescribed together. Both medications require a prescription and should be taken exactly as directed to avoid resistance and ensure effectiveness.
