Cefadroxil is an antibiotic used to treat bacterial infections of the skin, throat, tonsils, and urinary tract. It belongs to the first-generation cephalosporin class, meaning it works by destroying the cell walls bacteria need to survive. It’s taken by mouth as a capsule or liquid suspension, and one of its main advantages over similar antibiotics is simpler dosing, often just once or twice a day.
Conditions Cefadroxil Treats
Cefadroxil is approved for three main categories of infection. For throat and tonsil infections, it targets group A strep, the bacterium behind strep throat. The standard course runs 10 days, even though symptoms usually improve well before that. Stopping early risks leaving enough bacteria alive to cause a rebound infection or, in the case of strep, complications like rheumatic fever.
For urinary tract infections, cefadroxil works against common culprits like E. coli, Klebsiella, and Proteus mirabilis. A review of clinical evidence found that first-generation cephalosporins like cefadroxil achieve bacteriological and clinical cure rates comparable to many traditional first-line UTI treatments, particularly for uncomplicated lower urinary tract infections. Because it reaches high concentrations in urine and has a narrow spectrum of coverage, it’s considered a good option when broader-spectrum antibiotics aren’t necessary.
For skin and soft tissue infections, including impetigo, cefadroxil is effective against both streptococci and staphylococci, including some penicillin-resistant staph strains. It’s also sometimes used off-label to prevent heart valve infections in people with certain heart conditions who are having dental or upper respiratory procedures, particularly when penicillin isn’t an option.
How It Compares to Similar Antibiotics
Cephalexin is the most commonly prescribed first-generation cephalosporin in the United States, used about 23 times more frequently than cefadroxil for all infections. The two drugs are chemically very similar (cefadroxil is essentially a modified version of cephalexin), and they cover the same bacteria. The practical difference comes down to convenience: cephalexin traditionally requires dosing three or four times a day, while cefadroxil can be taken once or twice daily. Despite being absorbed completely and rapidly after swallowing, cefadroxil maintains measurable levels in the body for up to 12 hours, which supports its less frequent dosing schedule.
For uncomplicated bladder infections, either drug works well. Both are sometimes chosen specifically as alternatives to fluoroquinolone antibiotics, which carry more side effect risks and contribute more to antibiotic resistance when used for simple UTIs.
Typical Dosing for Adults and Children
Adults with strep throat or skin infections typically take 1 gram per day, either as a single dose or split into two doses. For uncomplicated bladder infections, the dose is 1 to 2 grams per day. More serious urinary tract infections call for 2 grams daily, divided into two doses.
Children’s doses are calculated by weight: 30 milligrams per kilogram of body weight per day. For throat infections and impetigo, this can be given as one daily dose or split into two. For urinary tract and most skin infections, the dose is split into two equal portions taken 12 hours apart. The liquid suspension comes in two strengths, and a child weighing around 40 pounds would typically take about 2 teaspoons of the lower-concentration version daily.
What to Know About Side Effects
Cefadroxil shares the side effect profile common to most cephalosporins. Digestive issues like nausea, diarrhea, and stomach discomfort are the most frequently reported problems. Allergic reactions can occur, ranging from mild rashes to, rarely, more serious reactions.
Because cephalosporins and penicillins are structurally related, there’s a small degree of cross-reactivity. The CDC lists cefadroxil as an alternative for strep throat in patients with penicillin allergy, but specifically warns against using it in people who have had an immediate-type allergic reaction to penicillin, meaning hives, throat swelling, or anaphylaxis. A delayed reaction like a mild rash from penicillin in the past is generally considered lower risk.
Why the Full Course Matters
One of the most important practical points with cefadroxil is completing the entire prescribed course. Symptoms of a throat or skin infection often improve within the first few days, which can make it tempting to stop taking the medication. But the bacteria causing the infection may not be fully eliminated yet. For strep throat specifically, the 10-day minimum course is designed to prevent complications, not just relieve the sore throat. The same principle applies to UTIs and skin infections: cutting the course short increases the chance the infection returns and may contribute to antibiotic resistance over time.