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Compare Amoxicillin vs. Penicillin

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

Key takeaways

Amoxicillin (Amoxil) and penicillin (Penicillin VK) are both penicillin antibiotics, but they treat different types of infections. Amoxicillin is used for a wide variety of infections, including ear, nose, throat, urinary tract, respiratory, and skin infections, and it is available in tablet, capsule, or liquid form. Penicillin VK is mainly used for strep infections, pneumonia, staph skin infections, and to prevent rheumatic fever or heart valve infections, available as a tablet or suspension. They are both possible first-choices for strep throat. Amoxicillin is more likely to cause diarrhea. Penicillin VK is less commonly used now due to bacterial resistance but is still a first-choice treatment for strep infections. Both should be taken as prescribed to avoid resistance, and you should inform your provider if you have a penicillin allergy, as both can cause severe allergic reactions.

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  • Amoxicillin (Amoxil)
    Penicillin v potassium (Penicillin VK)
  • Amoxicillin (Amoxil)
    Penicillin v potassium (Penicillin VK)

  • Summary of Amoxicillin vs. Penicillin

    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.

    Summary for Penicillin antibiotic
    Prescription only

    Penicillin V potassium (Penicillin VK) is an antibiotic used to treat several types of infections throughout the body in adults and children. It's available as tablets and suspension that are taken by mouth. The dosage depends on the type of infection you have and how severe it is, but the medication is typically taken every 6 to 12 hours. Side effects include nausea, diarrhea, and vomiting.

  • Indications of Amoxicillin vs. Penicillin

    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)
    Indications for
    •Certain types of streptococcal infections, such as upper respiratory tract infections, strep throat, scarlet fever, erysipelas (a type of skin infection)
    •Pneumococcal respiratory tract infections
    •Staphylococcal skin infections
    •Vincent's gingivitis
    •Prevention of rheumatic fever or chorea (long-term problems from strep infection)
    •Prevention of heart valve infections in certain people with heart problems

  • Pros and Cons of Amoxicillin vs. Penicillin

    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
    Pros and Const for Penicillin antibiotic
    Pros
    •Works well to treat many different bacterial infections
    •Can use for adults and children
    •Can be taken with or without food
    •Available as a tablet and suspension
    Cons
    •Can cause stomach side effects like nausea, vomiting, and diarrhea
    •Might not be able to take this medication if you've had a severe allergy to penicillin
    •Not recommended for treating a cold or the flu because these are viral infections
    •Needs to be taken every 6 to 8 hours

  • Common Side Effects of Amoxicillin vs. Penicillin

    Common Side Effects for
    •Diarrhea
    •Nausea
    •Vomiting
    •Rash
    Common Side Effects for
    •Nausea
    •Vomiting
    •Stomach upset
    •Diarrhea

  • Warnings of Amoxicillin vs. Penicillin

    Common Side Effects for
    •Severe allergic and skin reactions
    •Diarrhea from Clostridioides difficile infection
    •Development of drug-resistant bacteria
    Common Side Effects for
    •Allergic reaction
    •Infectious diarrhea
    •Development of drug-resistant bacteria

  • Prices with our coupons for Amoxicillin vs. Penicillin

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