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Compare Penicillin vs. Bactrim

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

Key takeaways

Sulfamethoxazole/trimethoprim (Bactrim) and penicillin v potassium (Penicillin VK) are antibiotics used to treat bacterial infections but differ in their classes and applications. Bactrim, a sulfonamide antibiotic combining sulfamethoxazole and trimethoprim, is effective for urinary tract infections, ear infections, and traveler's diarrhea. It is available in tablet, liquid, and injection forms but is not suitable for those with a sulfa allergy or pregnant women. Common side effects include nausea, vomiting, and diarrhea. Penicillin VK, a penicillin antibiotic, is primarily used for strep infections and some pneumococcal and staph infections. It is available as a generic in tablet and suspension forms and has fewer side effects, such as nausea and diarrhea. However, many bacteria are resistant to it, and it is not recommended for those allergic to penicillin or cephalosporins. Both medications require completing the full course to prevent bacterial resistance.

  • Penicillin v potassium (Penicillin VK)
    Sulfamethoxazole/trimethoprim
  • Penicillin v potassium (Penicillin VK)
    Sulfamethoxazole/trimethoprim

  • Summary of Penicillin vs. Bactrim

    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.

    Summary for Sulfonamide antibiotic
    Prescription only

    Sulfamethoxazole/trimethoprim (sometimes known as SMZ/TMP) is a combination medication containing an antifolate and sulfa antibiotic. It's used to treat different types of infections, such as urinary tract infections (UTIs), ear infections, and lung infections. This antibiotic has two different brand names, Bactrim and Septra, and it's also available as a lower-cost generic. It's a tablet that's taken by mouth, typically twice daily for most types of infections. This antibiotic also comes as a suspension under the brand name Sulfatrim for people who can't swallow tablets and as an injection for people in the hospital. Common side effects include nausea, diarrhea, and rash.

  • Indications of Penicillin vs. Bactrim

    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
    Indications for
    •Urinary tract infection (UTI)
    •Lower respiratory tract infection (e.g., Pneumocystis pneumonia, infections related to bronchitis)
    •Diarrhea caused by Shigella (shigellosis)
    •Travelers' diarrhea - tablet or liquid only
    •Ear infections - tablet or liquid only

  • Pros and Cons of Penicillin vs. Bactrim

    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
    Pros and Const for Sulfonamide antibiotic
    Pros
    •Treats many types of bacterial infections
    •Can be given to children as young as 2 months old to treat certain infections
    •Available as a lower-cost generic
    Cons
    •Can upset your stomach and make your skin more sensitive to the sun
    •Not the best choice for people with liver or kidney problems
    •Not recommended if you're pregnant
    •Can't take if you have a sulfa allergy

  • Common Side Effects of Penicillin vs. Bactrim

    Common Side Effects for
    •Nausea
    •Vomiting
    •Stomach upset
    •Diarrhea
    Common Side Effects for
    •Nausea
    •Vomiting
    •Diarrhea
    •Loss of appetite
    •Rash
    •Hives
    •Skin sensitivity to sun or light

  • Warnings of Penicillin vs. Bactrim

    Common Side Effects for
    •Allergic reaction
    •Infectious diarrhea
    •Development of drug-resistant bacteria
    Common Side Effects for
    •Not for use during pregnancy
    •Severe allergic reactions and skin reactions
    •Low platelet counts and risk for bleeding
    •Diarrhea from Clostridioides difficile infection
    •Low sodium levels and high potassium levels
    •Blood cell-related problems
    •Problems with processing phenylalanine - for people with phenylketonuria (PKU) only

  • Prices with our coupons for Penicillin vs. Bactrim

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