Compare Flagyl vs. Bactrim
Head-to-head comparisons of medication uses, side effects, warnings, and more.
Key takeaways
Metronidazole (Flagyl) and sulfamethoxazole/trimethoprim (Bactrim) are both antibiotics, but they belong to different classes and treat different types of infections. Metronidazole is a nitroimidazole antibiotic that targets bacterial and parasitic infections, such as bacterial vaginosis and trichomoniasis. In contrast, sulfamethoxazole/trimethoprim is a combination of a sulfonamide and an antifolate, used for infections like urinary tract infections (UTIs) and ear infections. Metronidazole is typically taken two to three times a day, while sulfamethoxazole/trimethoprim is usually taken twice a day. Both medications are available as lower-cost generics. However, metronidazole has a serious interaction with alcohol, requiring you to avoid it during treatment and for three days after. Sulfamethoxazole/trimethoprim can make your skin more sensitive to the sun and is not recommended if you have a sulfa allergy. Both medications have their own sets of side effects and specific warnings, so it's important to follow your healthcare provider's instructions closely.
- Metronidazole (Flagyl)Sulfamethoxazole/trimethoprim
- Metronidazole (Flagyl)Sulfamethoxazole/trimethoprim
Summary of Flagyl vs. Bactrim
Summary for Nitroimidazole antibioticPrescription onlyMetronidazole (Flagyl) is an oral antibiotic for adults and children. It's used to treat certain bacterial and parasitic infections, including bacterial vaginosis (a type of vaginal bacteria infection) and trichomoniasis (a sexually transmitted infection, or STI). Metronidazole (Flagyl) is taken by mouth, typically 3 times a day. Some common side effects of this medication include diarrhea, nausea, and vomiting. Avoid drinking alcohol while taking and for 3 days after stopping metronidazole (Flagyl) because this combination can cause a serious reaction. Metronidazole (Flagyl) is available as a lower-cost generic.
Summary for Sulfonamide antibioticPrescription onlySulfamethoxazole/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 Flagyl vs. Bactrim
Indications forTreatment of certain bacterial and parasitic infections, including:
•Amebiasis (parasitic gut infection)•Serious bacterial infections, such as:•Abdominal infection (including peritonitis)•Skin infections•Gynecological infections (including endometritis)•Bloodstream infection (septicemia)•Bone and joint infections•Central nervous system infections (meningitis)•Lung infections (lower respiratory tract infections)•Heart infection (endocarditis)Indications forPros and Cons of Flagyl vs. Bactrim
Pros and Const for Nitroimidazole antibioticPros•Taken by mouth•Available as a lower-cost generic medication•Can be used to treat different types of bacterial infection•Immediate-release formulations can be taken with or without foodCons•Immediate-release formulations needs to be taken multiple times a day for most infections•Serious interaction with alcohol•Can cause metallic taste in mouth•Not recommended while breastfeedingPros and Const for Sulfonamide antibioticPros•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 genericCons•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 allergyCommon Side Effects of Flagyl vs. Bactrim
Common Side Effects forPlease note: These are common side effects reported by people who took extended-release metronidazole (Flagyl)
•Headache (18%)•Inflammation of the vagina (15%)•Nausea (10%)•Metallic taste (9%)•Flu-like symptoms (6%)Common Side Effects forWarnings of Flagyl vs. Bactrim
Common Side Effects for•Possible risk of cancer•Serious allergic reactions•Brain and nerve problems•Liver and kidney problems•Risk of fungal infection•Risk of drug resistance•Lower white blood cell counts•Interaction with other medicationsCommon 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) onlyPrices with our coupons for Flagyl vs. Bactrim
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