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Compare Cephalexin vs. Amoxicillin

Head-to-head comparisons of medication uses, side effects, warnings, and more.

Key takeaways

Cephalexin (Keflex) and Amoxicillin (Amoxil) are both antibiotics used to treat bacterial infections, such as urinary tract infections (UTIs) and ear infections. However, they belong to different medication classes. Cephalexin is a cephalosporin antibiotic, while Amoxicillin is a penicillin antibiotic. Cephalexin is available as capsules, tablets, and liquid suspensions, and is typically taken 2 to 4 times a day. Amoxicillin comes in tablets, capsules, chewable tablets, and liquid forms, and is usually taken 2 to 3 times a day. Both medications are available as lower-cost generics. Common side effects for both include nausea, vomiting, and diarrhea, but Amoxicillin can also cause a rash. Cephalexin may interact with metformin, probenecid and warfarin while Amoxicillin can interact with probenacid, warfarin and allopurinol. If you have a penicillin allergy, you might also be allergic to Amoxicillin, but the risk is lower with Cephalexin.

  • Cephalexin
    Amoxicillin (Amoxil)
  • Cephalexin
    Amoxicillin (Amoxil)

  • Summary of Cephalexin vs. Amoxicillin

    Summary for Cephalosporin antibiotic
    Prescription only

    Cephalexin is a common antibiotic that's used to treat many different bacterial infections including urinary tract infections (UTIs), ear infections, and sinus infections, to name a few. Cephalexin is a cephalosporin antibiotic that kills bacteria to fight the infection. It's safe to use in people over the age of 1, and it's typically taken by mouth 2 to 4 times per day. This medication is available as a lower-cost generic capsule, tablet, and suspension; the brand name Keflex is no longer available. Side effects can include nausea, vomiting, and diarrhea.

    Summary for Penicillin antibiotic
    Prescription only

    Amoxicillin (Amoxil) is a penicillin antibiotic that's used to treat a wide variety of bacterial infections, such as sinus infections, ear infections, strep throat, and urinary tract infections (UTIs). It's available as oral pills, a chewable tablet, and an oral liquid. Amoxicillin (Amoxil) is well-tolerated, but possible side effects include diarrhea, vomiting, and rash.

  • Indications of Cephalexin vs. Amoxicillin

    Indications for
    •Respiratory tract infections
    •Ear infections
    •Skin infections
    •Bone infections
    •Urinary tract infections (UTIs)
    •Reproductive system infections
    Indications for
    •Upper respiratory tract infections (ear, nose, and throat infections)
    •Lower respiratory tract infections (e.g., pneumonia, bronchitis)
    •Urinary tract infections (UTIs)
    •Skin infections (e.g., cellulitis)
    •Helicobacter pylori infection (adults only)

  • Pros and Cons of Cephalexin vs. Amoxicillin

    Pros and Const for Cephalosporin antibiotic
    Pros
    •Treats several common types of bacterial infections
    •Can use for adults and children over the age of 1
    •Available as a liquid for people who have trouble swallowing pills
    •Available as a lower-cost generic
    Cons
    •Usually need to take a few times per day
    •Might not be able to take if you're allergic to penicillins or other cephalosporin antibiotics
    •Not recommended for the cold or flu (these are viral illnesses, not bacterial infections)
    Pros and Const for Penicillin antibiotic
    Pros
    •Works well to treat many different bacterial infections
    •Can use for adults and children
    •Available in many forms (e.g., oral tablet, chewable tablet, capsule, liquid)
    •Liquid form comes in many different flavors to make it taste better
    Cons
    •Might need to take up to three times per day
    •Can cause stomach side effects like nausea, vomiting, and diarrhea
    •Not the best option if you have severe kidney problems
    •Might not be able to take this medication if you've had a severe allergy to penicillin

  • Common Side Effects of Cephalexin vs. Amoxicillin

    Common Side Effects for
    •Diarrhea
    •Nausea
    •Vomiting
    •Indigestion
    •Stomach pain
    Common Side Effects for
    •Diarrhea
    •Nausea
    •Vomiting
    •Rash

  • Warnings of Cephalexin vs. Amoxicillin

    Common Side Effects for
    •Allergic reactions
    •Diarrhea from Clostridioides difficile infection
    •Development of drug-resistant bacteria
    •Seizures
    •Higher risk of bleeding
    Common Side Effects for
    •Severe allergic and skin reactions
    •Diarrhea from Clostridioides difficile infection
    •Development of drug-resistant bacteria

  • Prices with our coupons for Cephalexin vs. Amoxicillin

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