Compare Bactrim vs. Keflex
Head-to-head comparisons of medication uses, side effects, warnings, and more.
Key takeaways
Sulfamethoxazole/trimethoprim (Bactrim, Septra) and cephalexin (Keflex) are both antibiotics used to treat bacterial infections, but they belong to different classes. Sulfamethoxazole/trimethoprim is a combination of a sulfonamide and an antifolate, while cephalexin is a cephalosporin antibiotic. Sulfamethoxazole/trimethoprim is typically taken twice a day and can be used for a variety of infections, including UTIs, ear infections, and certain types of pneumonia. Cephalexin, on the other hand, is usually taken 2 to 4 times a day and is used for respiratory tract infections, skin infections, and bone infections, among others. Both medications are available in generic forms and can be taken as tablets, capsules, or liquid suspensions. However, sulfamethoxazole/trimethoprim is not recommended for people with sulfa allergies, while cephalexin may not be suitable for those with severe allergies to penicillin or other cephalosporins. Common side effects for both include nausea, vomiting, and diarrhea, but sulfamethoxazole/trimethoprim can also make your skin more sensitive to the sun.
- Sulfamethoxazole/trimethoprimCephalexin
- Sulfamethoxazole/trimethoprimCephalexin
Summary of Bactrim vs. Keflex
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.
Summary for Cephalosporin antibioticPrescription onlyCephalexin 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.
Indications of Bactrim vs. Keflex
Indications forIndications forPros and Cons of Bactrim vs. Keflex
Pros 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 allergyPros and Const for Cephalosporin antibioticPros•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 genericCons•Usually need to take a few times per day•Not recommended for the cold or flu (these are viral illnesses, not bacterial infections)Common Side Effects of Bactrim vs. Keflex
Common Side Effects forCommon Side Effects for•Diarrhea•Nausea•Vomiting•Indigestion•Stomach painWarnings of Bactrim vs. Keflex
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) onlyCommon Side Effects for•Allergic reactions•Diarrhea from Clostridioides difficile infection•Development of drug-resistant bacteria•Seizures•Higher risk of bleedingPrices with our coupons for Bactrim vs. Keflex
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