Flagyl vs. Keflex

• Are Flagyl and Keflex the Same Thing?
• What Are Possible Side Effects of Flagyl?
• What Are Possible Side Effects of Keflex?
• What is Flagyl?
• What is Keflex?
• What drugs interact with Flagyl?
• What drugs interact with Keflex?
• How Should Flagyl Be Taken?
• How Should Keflex Be Taken?

Flagyl, Flagyl ER, and Flagyl Injection (metronidazole) and Keflex (cephalexin) are antibiotics used to treat bacterial infections.

Keflex is also used before dental procedures in patients identified with certain heart-related conditions to prevent bacterial infections of the heart known as endocarditis.

Flagyl and Keflex are different types of antibiotics. Flagyl is a nitroimidazole antibiotic and Keflex is a cephalosporin antibiotic.

Side effects of Flagyl include:

• nausea,
• abdominal cramps,
• stomach upset,
• vomiting,
• diarrhea,
• constipation,
• headache,
• weight loss (anorexia),
• dizziness,
• dry mouth,
• dark-colored urine, or
• a metallic taste in the mouth or changes in taste.

Uncomfortable side effects that may become serious are:

• fevers,
• pain with urination,
• mouth sores,
• tingling or pricking sensations that may become permanent,
• brain disease, and
• seizures.

Serious but unlikely side effects of Flagyl include:

• unsteadiness,
• seizures,
• mood changes,
• numbness or tingling of the hands or feet, and
• painful urination.

Common side effects of Keflex include:

• diarrhea,
• dizziness,
• tiredness,
• headache,
• stomach upset,
• abdominal pain,
• joint pain,
• vaginal itching or discharge,
• nausea,
• vomiting,
• itching,
• swelling, and
• rash.

Flagyl, Flagyl ER, and Flagyl Injection (metronidazole) are antimicrobial drugs used to treat bacterial vaginosis, trichomonas, amebiasis, and anaerobic bacterial infections.

What is Keflex?

Keflex (cephalexin) is a cephalosporin antibiotic prescribed to treat bacterial infections. Keflex is also used before dental procedures in patients identified with certain heart-related conditions to prevent bacterial infections of the heart known as endocarditis.

Flagyl may interact with blood thinners or seizure medications.

Flagyl may also interact with cimetidine, lithium, or disulfiram.

Keflex may interact with blood thinners.

Keflex may also interact with metformin or probenecid.

Flagyl is supplied in 250 and 500 mg strength tablets, Flagyl ER is available in 750 mg strength tablets, and Flagyl Injection in 500 mg strength in a buffered 100 ml vial. Dosage is quite variable and dependent upon the severity of disease and other considerations made by the treating physician. Most of the serious side effects may occur with any of these three preparations of Flagyl. Flagyl may cause liver enzyme levels to increase; lithium and creatinine levels should be checked to avoid lithium toxicity or renal compromise. Alcohol may increase the side effects of Flagyl. Patients on disulfiram should not take Flagyl until they have had a two week interval without taking disulfiram, especially alcoholic patients, to avoid psychotic reactions. Treatment in pregnant women (during first 3 months is not advised) or women who are breastfeeding should only be done if the benefits outweigh the potential problems. Flagyl passes into breast milk and may harm a nursing baby. Consult your doctor before breastfeeding. Except for use in amebiasis, studies in pediatric patients are not available; Flagyl ER has no pediatric studies.

Keflex dosage depends on the condition being treated.