Strep throat isn’t just a sore throat-it’s a bacterial infection that can make swallowing painful, spike your fever, and leave you drained for days. If your doctor says it’s strep, they might prescribe cefadroxil. But is it really the right choice? How does it compare to penicillin or amoxicillin? And what happens if you skip a dose or stop too soon?
What Is Cefadroxil?
Cefadroxil is an oral antibiotic in the cephalosporin family, a class of drugs that kill bacteria by breaking down their cell walls. It’s not new-it’s been around since the 1970s-but it’s still used today, especially when penicillin isn’t an option. Unlike some broad-spectrum antibiotics, cefadroxil is focused on common skin and throat infections, including strep throat caused by Streptococcus pyogenes.
The FDA approved cefadroxil for strep throat based on clinical trials showing it clears the infection as effectively as penicillin in most cases. Studies from the 1980s and 1990s, including one published in the Journal of Infectious Diseases, found cure rates above 90% when taken correctly. Today, it’s listed as an alternative first-line treatment in guidelines from the Infectious Diseases Society of America (IDSA), especially for people allergic to penicillin.
How Effective Is Cefadroxil for Strep Throat?
When taken as directed, cefadroxil reduces symptoms within 24 to 48 hours. Most people feel significantly better by day three. But effectiveness isn’t just about how fast you feel better-it’s about making sure the bacteria are fully gone.
Penicillin and amoxicillin are still the top choices because they’re cheap, well-studied, and have a narrow spectrum (meaning they don’t wipe out good bacteria as much). But cefadroxil matches them in cure rates. A 2018 review in Clinical Infectious Diseases analyzed 12 trials comparing cephalosporins to penicillin for strep throat. Cefadroxil performed just as well, with no significant difference in recurrence or complications like rheumatic fever.
One advantage? Cefadroxil is taken just once or twice a day. That makes it easier to stick with than amoxicillin, which usually requires three doses daily. For kids or busy adults, that can mean better compliance-and fewer relapses.
When Is Cefadroxil Prescribed for Strep Throat?
Doctors don’t automatically reach for cefadroxil. First, they confirm it’s strep-not a virus. That means a rapid antigen test or throat culture. If it’s positive, they consider:
- Penicillin allergy (mild rash or severe anaphylaxis)
- Previous treatment failure with amoxicillin
- Patient preference or difficulty taking multiple daily doses
- Local resistance patterns (rare, but some areas report higher resistance to older antibiotics)
Cefadroxil is also used when someone has a history of recurrent strep throat. In those cases, a longer course might be needed, but that’s decided case by case.
Dosage and How to Take It
For adults and teens over 12, the standard dose is 1 gram once daily, or split into 500 mg every 12 hours. For children, it’s 30 mg per kilogram of body weight per day, split into one or two doses. A 40-pound child would get about 550 mg total per day-usually 275 mg twice a day.
It’s taken by mouth, with or without food. But taking it with food can reduce stomach upset. The full course is typically 10 days. Don’t stop early, even if you feel fine. Stopping too soon is the #1 reason strep comes back-and it increases the risk of serious complications like kidney inflammation or rheumatic fever.
Swallow the capsule whole. Don’t crush or open it unless your doctor says to. If you’re using the liquid form, shake the bottle well before each dose. Use the measuring cup that comes with it-not a kitchen spoon.
Side Effects and Risks
Cefadroxil is generally well-tolerated. Most people have no issues. But side effects can happen:
- Diarrhea (mild in most cases)
- Nausea or vomiting
- Stomach cramps
- Rash (could be harmless or a sign of allergy)
- Yeast infections (especially in women)
Severe reactions are rare but serious. Call your doctor immediately if you develop:
- Watery or bloody diarrhea (could be C. diff infection)
- Swelling of the face, lips, or tongue
- Difficulty breathing
- Hives or blistering skin
If you’ve ever had an allergic reaction to penicillin, tell your doctor. About 10% of people with penicillin allergies also react to cephalosporins like cefadroxil. It’s not a guarantee-but it’s a red flag.
What If Cefadroxil Doesn’t Work?
If your fever doesn’t drop after 48 hours, or your sore throat gets worse, contact your doctor. It could mean:
- The infection isn’t strep (maybe mono or a virus)
- The bacteria are resistant (uncommon with cefadroxil)
- You didn’t take the full course
- You have a secondary infection
Your doctor might switch you to another antibiotic-like clindamycin or azithromycin-or order more tests. Don’t try to double the dose or take leftover antibiotics from a previous illness. That can make things worse.
Cefadroxil vs. Other Strep Throat Antibiotics
Here’s how cefadroxil stacks up against the most common options:
| Antibiotic | Dosing Frequency | Duration | Common Side Effects | Best For |
|---|---|---|---|---|
| Cefadroxil | Once or twice daily | 10 days | Mild GI upset, rash | Penicillin allergy, easier dosing |
| Penicillin V | Four times daily | 10 days | Very few | First choice, low cost |
| Amoxicillin | Three times daily | 10 days | Diarrhea, rash | Children, better taste |
| Azithromycin | Once daily for 5 days | 5 days | Nausea, diarrhea | Severe penicillin allergy |
| Clindamycin | Three times daily | 10 days | Strong GI upset, C. diff risk | Recurrent or resistant cases |
For most people, penicillin or amoxicillin still win. But cefadroxil fills a real gap: it’s simple to take, effective, and safe for many with mild penicillin allergies. It’s not the first pick-but it’s a solid second.
What to Avoid While Taking Cefadroxil
There’s no major food interaction with cefadroxil, unlike some antibiotics. But here’s what to watch:
- Alcohol: It won’t cause a dangerous reaction, but it can worsen stomach upset and slow healing.
- Probiotics: Taking them during treatment may help prevent diarrhea. Look for strains like Lactobacillus rhamnosus or Saccharomyces boulardii.
- Other antibiotics: Don’t mix cefadroxil with other antibiotics unless your doctor says so.
- Birth control: Some antibiotics reduce effectiveness. Use backup contraception during treatment and for one week after.
When to See a Doctor After Starting Cefadroxil
Most people recover fully. But call your doctor if:
- Fever lasts more than 48 hours after starting the antibiotic
- Swallowing becomes harder or you can’t drink fluids
- You develop a rash that spreads or blisters
- You have severe diarrhea (more than 3 watery stools a day)
- Your symptoms improve, then come back worse
These could signal complications like abscesses, rheumatic fever, or post-streptococcal glomerulonephritis. Early action prevents long-term damage.
Preventing Strep Throat After Treatment
Once you’re done with cefadroxil, you’re not immune. Strep spreads easily through coughs, sneezes, and shared items. To avoid getting it again:
- Replace your toothbrush after 2-3 days of starting antibiotics
- Wash hands often, especially before eating
- Avoid close contact with people who have strep until they’ve been on antibiotics for 24 hours
- Don’t share drinks, utensils, or towels
There’s no vaccine for strep throat. Prevention is about hygiene and awareness-not magic pills.
Is cefadroxil better than amoxicillin for strep throat?
Cefadroxil isn’t better-it’s different. Amoxicillin is still the top choice for most people because it’s cheaper and has decades of proven safety. Cefadroxil is preferred when someone can’t take amoxicillin due to allergies or if they struggle with taking medicine three times a day. Both work equally well if taken correctly.
Can I take cefadroxil if I’m allergic to penicillin?
Maybe. About 10% of people with penicillin allergies react to cephalosporins like cefadroxil. If you had a mild rash with penicillin, your doctor might still prescribe it. If you had swelling, trouble breathing, or anaphylaxis, avoid cefadroxil. Always tell your doctor your full allergy history.
How long does it take for cefadroxil to work on strep throat?
Most people notice improvement within 24 to 48 hours. Fever drops, swallowing gets easier, and energy returns. But you must finish the full 10-day course-even if you feel fine. Stopping early can let bacteria survive and come back stronger.
Does cefadroxil cause yeast infections?
Yes, it can. Antibiotics kill both bad and good bacteria, which can let yeast overgrow. Women may get vaginal yeast infections. Symptoms include itching, burning, and thick white discharge. Over-the-counter antifungals like miconazole can help. Talk to your doctor if symptoms persist.
Can kids take cefadroxil for strep throat?
Yes, and it’s commonly used for children. The dose is based on weight-usually 30 mg per kilogram per day, split into one or two doses. It’s often preferred over amoxicillin for kids who hate the taste or have trouble swallowing pills, because it comes in a sweet liquid form. Always use the measuring tool provided.
What happens if I miss a dose of cefadroxil?
If you miss a dose, take it as soon as you remember. But if it’s almost time for the next dose, skip the missed one. Don’t double up. Missing one dose isn’t a disaster, but missing multiple doses reduces effectiveness and raises the risk of antibiotic resistance.
Final Thoughts
Cefadroxil isn’t the first antibiotic doctors reach for-but it’s a reliable, well-tested option when you need it. It works. It’s easy to take. And for many, it’s the best alternative when penicillin isn’t safe. The key isn’t which drug you get-it’s taking it exactly as prescribed. Skip doses, stop early, or ignore side effects, and you risk more than just a sore throat. You risk complications that can last a lifetime.