Cefdinir vs. amoxicillin: Differences and similarities

In this article:

• Main differences
• Conditions treated
• Which is more effective?
• Coverage and cost comparison
• Side effects
• Drug interactions
• Cefdinir and amoxicillin warnings
• FAQ

In this article

• Main differences
• Conditions treated
• Which is more effective?
• Coverage and cost comparison
• Side effects
• Drug interactions
• Cefdinir and amoxicillin warnings
• FAQ

Cefdinir and amoxicillin are generic antibiotics used to treat bacterial infections. Both belong to the beta-lactam family but differ in subcategory: Cefdinir is a third-generation cephalosporin, while amoxicillin is a penicillin-type antibiotic. Both work by blocking the ability of bacteria to maintain their cell wall, which weakens and kills the bacteria. Although they may work in similar ways, they have specific uses, dosing, and potential side effects.

What are the main differences between cefdinir and amoxicillin?

Cefdinir

Since the Omnicef brand was discontinued, Cefdinir is only available as a generic drug. It is a third-generation cephalosporin that covers different strains of gram-positive and gram-negative bacteria. Compared to earlier cephalosporin antibiotics, Cefdinir has broader coverage for gram-negative bacteria. It is available as an oral capsule and liquid suspension. Cefdinir is typically given once or twice daily.

 

Amoxicillin

Amoxicillin, available under brand names like Amoxil and Moxatag, is a penicillin-type antibiotic that has a structure similar to that of penicillin. However, it covers more bacterial strains than penicillin. In many cases, it is combined with clavulanic acid, a beta-lactamase inhibitor that makes it stronger against certain bacteria. Amoxicillin is available as an oral capsule, tablet, chewable tablet, and liquid oral suspension. It is usually taken two or three times per day, depending on the infection being treated.

Cefdinir vs. Amoxicillin comparison
	Cefdinir	Amoxicillin
Drug class	Antibiotic Beta-lactam Cephalosporin	Antibiotic Beta-lactam Penicillin-type
Brand/generic status	Only available as a generic drug (brand name discontinued)	Brand and generic versions available
What is the brand name?	Omnicef	Amoxil, Larotid
What form(s) does the drug come in?	Oral capsule Powder for oral suspension	Oral capsule Powder for oral suspension Oral tablet Oral tablet, chewable
What is the standard dosage?	300 mg every 12 hours or 600 mg once daily (dosage depends on the infection being treated)	500 mg every 12 hours or 250 mg every 8 hours (dosage depends on the infection being treated)
How long is the typical treatment?	5–10 days (duration depends on the infection being treated)	7–10 days (duration depends on the infection being treated)
Who typically uses the medication?	Adults, children, and infants 6 months and older	Adults, children, and infants 3 months and older

 

Conditions treated by cefdinir and amoxicillin

Cefdinir is FDA approved to treat acute otitis media, or middle ear infection, as well as skin and soft tissue infections. Cefdinir is also approved to treat upper and lower respiratory tract infections. Upper respiratory tract infections include sinusitis, pharyngitis, and tonsillitis. Lower respiratory tract infections include community-acquired pneumonia in adults and children 13 years of age and older. 

Amoxicillin is also approved to treat ear, nose, throat, and sinus infections. Amoxicillin may be prescribed to treat lower respiratory tract infections such as community-acquired pneumonia caused by Streptococcus pneumonia. Unlike cefdinir, amoxicillin is also commonly used to treat H. pylori infections (alongside clarithromycin and omeprazole or lansoprazole). 

Cefdinir vs. amoxicillin: Conditions treated
Condition	Cefdinir	Amoxicillin
Acute otitis media	Yes	Yes
Chronic bronchitis (flare-ups)	Yes	Yes
Sinusitis	Yes	Yes
Pharyngitis	Yes	Yes
Community-acquired pneumonia	Yes	Yes
Skin and soft tissue infections	Yes	Yes
Urinary tract infections	Yes	Yes
H. Pylori infection	No	Yes

 

Is cefdinir or amoxicillin more effective?

Cefdinir is effective against infections caused by gram-positive bacteria, including Staphylococcus aureus, Streptococcus pneumoniae (penicillin-susceptible strains only), and Streptococcus pyogenes. Cefdinir is also effective against gram-negative bacteria such as Haemophilus influenzae, Haemophilus parainfluenzae, and Moraxella catarrhalis. 

Amoxicillin is effective against infections caused by gram-positive bacteria such as Streptococcus and Staphylococcus species. Amoxicillin is also active against gram-negative bacteria, including Haemophilus influenzae, E. coli, and Helicobacter pylori.

Clinical Trials

Cefdinir and amoxicillin are both effective antibiotics, but the best choice depends on the type of infection, the bacteria causing it, and local resistance rates. Amoxicillin is typically preferred as the first-line option for ear infections and strep throat. On the other hand, cefdinir may be used in people with penicillin allergies or those who prefer once-daily dosing.

Some multicenter clinical trials have shown that cefdinir and amoxicillin (with clavulanate) are similar in effectiveness for certain infections. For example, when treating bacterial sinusitis, cefdinir was just as effective as amoxicillin-clavulanate after 10 days of treatment. In any case, it’s best to consult a healthcare provider about which antibiotic will be most effective. 

Coverage and cost comparison of cefdinir vs. amoxicillin

As generic antibiotics, cefdinir and amoxicillin are widely available. Almost all Medicare and insurance plans will cover cefdinir and amoxicillin. The typical retail cost of generic cefdinir could be more than $100 for a treatment course. With a SingleCare coupon card, this cost may be reduced to about $15 for 20, 300 mg capsules. 

Amoxicillin is available in generic and brand-name versions. The average cost of generic amoxicillin capsules is around $20 for 21, 500 mg capsules. Using a SingleCare coupon card can lower the price to around $9. 

Cefdinir vs. amoxicillin: Cost and coverage
	Cefdinir	Amoxicillin
Typically covered by insurance?	Yes	Yes
Typically covered by Medicare?	Yes	Yes
Quantity	20, 300 mg capsules	21, 500 mg tablets
SingleCare cost*	$15	$9

* Cost at time of publication. Drug prices fluctuate and vary by pharmacy and location. 

Common side effects of cefdinir vs. amoxicillin

The most common side effects associated with cefdinir and amoxicillin are diarrhea, nausea, vomiting, and rash.

Amoxicillin may be more likely to cause headaches when taken with clarithromycin and lansoprazole for H. pylori infections. In addition, studies suggest that amoxicillin combined with clavulanate may cause more diarrhea than cefdinir in pediatric patients with ear infections. 

More serious side effects of cefdinir and amoxicillin include allergic or hypersensitivity reactions. Those who experience adverse events like trouble breathing, swelling, or a severe rash should seek medical attention immediately.  

Drug interactions of cefdinir vs. amoxicillin

Cefdinir can interact with aluminum- and magnesium-containing antacids, as well as iron supplements. These products can decrease the absorption of cefdinir and reduce its effectiveness. It is recommended to separate cefdinir from these over-the-counter medicines by at least two hours. Iron can cause a harmless reddish color in stools when taken with cefdinir.

Both cefdinir and amoxicillin can interact with gout medicines such as probenecid and allopurinol. These prescription drugs can increase antibiotic levels in the blood and increase the risk of side effects. In addition, cefdinir and amoxicillin may amplify the effects of warfarin, which may cause an increased risk of bleeding.

Cefdinir vs. amoxicillin: Drug interactions
Drug	Drug Class	Cefdinir	Amoxicillin
Aluminum hydroxide Magnesium hydroxide	Antacids	Yes	No
Ferrous sulfate Ferrous gluconate Ferrous fumarate	Iron supplements	Yes	No
Probenecid Allopurinol	Antigout	Yes	Yes
Warfarin	Anticoagulant	Yes	Yes

This may not be a complete list of all possible drug interactions. Consult a healthcare provider about all the medications you may be taking. 

Warnings of cefdinir and amoxicillin

Amoxicillin should be avoided if you have a penicillin allergy. Because it’s chemically similar to penicillin, taking amoxicillin may trigger a severe allergic reaction in people with a true penicillin allergy. Cefdinir is less likely to cause a reaction in those with penicillin allergies. 

Diarrhea is one of the most common side effects of antibiotics like cefdinir and amoxicillin. These medicines can increase the chance of a more serious type of diarrhea caused by Clostridium difficile. If you have a medical history of C. diff infections, your healthcare provider may need to monitor or stop treatment.

These antibiotics should only be prescribed for infections caused by bacteria. They will not help with viral infections such as COVID-19. Cefdinir and amoxicillin are most effective when targeting susceptible bacteria. If they are used incorrectly, bacteria could become resistant and cause more severe infections.

Frequently asked questions about cefdinir vs. amoxicillin

What is cefdinir?

Cefdinir is a cephalosporin antibiotic used to treat certain bacterial infections, including ear, throat, and skin infections. It is also FDA approved to treat sinusitis and lower respiratory tract infections. Cefdinir is also known by the brand name Omnicef, which has been discontinued. 

What is amoxicillin?

Amoxicillin is a penicillin-type antibiotic that is used to treat various bacterial infections of the ear, nose, and throat. It can also treat lower respiratory tract infections and H. pylori infections. Amoxicillin is often combined with clavulanate, or clavulanic acid, under the brand name Augmentin. 

Are cefdinir and amoxicillin the same?

Cefdinir and amoxicillin are not the same. Although they are both part of a broad-spectrum group of antibiotics called beta-lactams, they have different nuances in how they’re used and dosed. 

Is cefdinir or amoxicillin better?

The more effective antibiotic is the one that works best against the bacterial strain causing the infection. For example, amoxicillin is preferred for H. pylori infections alongside other medications. However, some people may prefer cefdinir as a once-daily option for certain infections or when they have an allergy to penicillin.

Can I use cefdinir or amoxicillin while pregnant?

There have been no adequate clinical studies to show that cefdinir or amoxicillin is safe during pregnancy. They are both deemed Pregnancy Category B drugs, which indicates a low risk for congenital disabilities. Still, they should only be used if necessary. Consult a healthcare provider for medical advice on the best option during pregnancy. 

Can I use cefdinir or amoxicillin with alcohol?

Alcohol does not directly interact with cefdinir or amoxicillin. However, it is not generally recommended to drink alcohol with antibiotics. Consuming excessive amounts of alcohol can increase the risk of adverse side effects like nausea and vomiting. Alcohol can also weaken the immune system and make it harder for the body to fight infections.