Compare Keflex vs. Flagyl
Head-to-head comparisons of medication uses, side effects, ratings, and more.
Treats bacterial infections.
Keflex (cephalexin) is good for treating many bacterial infections, and is available as a generic.
●●●●●
3.7/ 5 average rating with 686 reviewsforKeflex
Treats and prevents bacterial infections.
Flagyl (metronidazole) is very good at treating certain bacterial infections, but you can't have any alcohol while on it since it'll make you throw up a lot.
Upsides
- Available in generic.
- Available in different forms: tablet, capsule, and suspension.
- Used to treat many types of bacterial infections.
- Can be taken with or without food.
- Generally few side effects compared with other antibiotics.
- Flagyl (metronidazole) is good at killing a variety of bacteria.
- Unlike many other antibiotics, Flagyl (metronidazole) is less likely to make bacteria resistant to it.
- Most forms are available as a generic, so it's relatively cheap.
Downsides
- Can cause diarrhea.
- You may need to take Keflex (cephalexin) 2 to 4 times a day, which can be hard to remember.
- If you're allergic to penicillins or other antibiotics, you might not be able to take this medicine.
- You can't drink alcohol while on Flagyl (metronidazole), and for at least 3 days after you finish it.
- Side effects can include nausea, headache, stomach upset, and a metallic taste in your mouth.
- If you're taking Flagyl (metronidazole) for a long time, there's a risk of more side effects, such as nerve damage.
- If you're on blood thinners, let your doctor know. Flagyl (metronidazole) can interact with your medicines and make you more likely to bleed.
Used for
- Bone infection
- Urinary tract infection
- Ear infection
- Respiratory tract infection
- Skin infection
- Community-acquired pneumonia
- Prevention of endocarditis
- Prevention of infection in people with prosthetic joint implants undergoing dental procedure
- Prosthetic joint infection
- Surgical site infection
- Amebiasis
- Infection caused by anaerobic bacteria
- Bacterial vaginosis
- Trichomoniasis
- Balantidiasis
- Bite wounds
- Clostridium difficile infection
- Crohn's disease
- Dientamoeba fragilis
- Giardiasis
- Helicobacter pylori eradication
- Periodontitis
- Pouchitis
- Prophylaxis against sexually-transmitted diseases following sexual assault
- Skin and soft tissue necrotizing infections
- Surgical site infections
- Tetanus
- Urethritis, nongonococcal
Dosage forms
- Pill
- Liquid
- Pill
- Extended-release pill
- Injection
Price
Lowest price
$4.84
Find instant savings near youLowest price
$8.30
Find instant savings near youWant to save even more money?
Sign up now for a 30-day trial and save up to 95% at CVS, Kroger, Albertsons, and other pharmacies.
Learn more
Reviews
686 reviews so far
64%
saidit'sworth it
48%
saiditworked well
14%
saidit'sa big hassle
Have you used Keflex (cephalexin)?
Leave a reviewNot enough review data.Leave a review
Side effects
The Keflex (cephalexin) FDA package insert doesn’t have numbers about how common side effects are.
13possible side effects
- Headache18%
- Nausea10%
- Metallic taste9%
- Genital itching5%
- Dizziness4%
- Diarrhea4%
- Stomach problems4%
- Overgrowth of yeast3%
- Stuffy nose3%
- Menstrual cramps3%
- Abnormal urine3%
- Dry mouth2%
- Urinary tract infection2%
Risks and risk factors
- Diarrhea
- New infections while taking Keflex (cephalexin)
- Weakened immune system
- Not taking Keflex (cephalexin) correctly
- Allergic reaction
- History of penicillin or cephalosporin allergies
- Seizure or brain problems
- Taking high doses of Flagyl (metronidazole)
- Taking Flagyl (metronidazole) for a long time
- Nerve damage
- Taking high doses of Flagyl (metronidazole)
- Taking Flagyl (metronidazole) for a long time
- Cancer
- New infection while taking Flagyl (metronidazole)
- Taking Flagyl (metronidazole) incorrectly
- Interaction with alcohol
- Drinking alcohol while taking Flagyl (metronidazole)