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Drug overview & main differences | Conditions treated | Efficacy | Insurance coverage and cost comparison | Side effects | Drug interactions | Warnings | FAQ
Cefdinir (Omnicef) and amoxicillin (Amoxil) are two antibiotics used to treat bacterial infections. Both drugs are part of a group of antibiotics called beta-lactams. They can treat a range of different infections such as respiratory tract infections, ear infections, and skin infections.
Like most beta-lactam antibiotics, cefdinir and amoxicillin work by inhibiting a bacteria’s ability to maintain its cell wall. By attacking this process, these antibiotics are able to break down the bacteria’s primary defense and means of reproduction.
Although they work in similar ways, cefdinir and amoxicillin are part of different subclasses of beta-lactam antibiotics. They also vary in how they’re used and which bacteria they’re most effective against.
What are the main differences between cefdinir and amoxicillin?
Cefdinir
Cefdinir is an antibiotic that is further classified as a cephalosporin. More specifically, it is a third-generation cephalosporin that covers different strains of gram-positive and gram-negative bacteria. Compared to earlier cephalosporin antibiotics (e.g., cephalexin, cefuroxime, and cefaclor), cefdinir has broader coverage for gram-negative bacteria.
Cefdinir (What is Cefdinir?) can treat infections such as community-acquired pneumonia, acute otitis media (AOM), bronchitis, and pharyngitis. It is available as an oral capsule and liquid suspension that can be administered once or twice daily depending on the dosage.
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Amoxicillin
Amoxicillin is a penicillin-type antibiotic that has a structure closely related to that of penicillin; however, unlike penicillin, amoxicillin covers more bacterial strains. Amoxicillin is often combined with clavulanic acid, a beta-lactamase inhibitor, which makes it a stronger antibiotic against certain bacteria.
Amoxicillin (What is Amoxicillin?) can treat H. pylori infections, lower respiratory tract infections, and gonorrhea among other infections. It is available as an oral capsule, tablet, chewable tablet, and liquid oral suspension. Amoxicillin is typically taken two or three times per day depending on the dosage and infection being treated.
| Main differences between cefdinir and amoxicillin | ||
|---|---|---|
| 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 | Moxatag, Amoxil |
| What form(s) does the drug come in? | Oral capsule Oral powder for suspension |
Oral capsule Oral powder for suspension Oral tablet Chewable tablet |
| What is the standard dosage? | 300 mg every 12 hours or 600 mg once daily
Dosing depends on the infection being treated |
500 mg every 12 hours or 250 mg every 8 hours
Dosing 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 |
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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, which cefdinir can treat in adults and children 13 years of age and older.
Amoxicillin is approved to treat ear, nose, and throat infections like sinusitis, pharyngitis, and tonsillitis. Amoxicillin is also approved to treat lower respiratory tract infections such as community-acquired pneumonia caused by streptococcus pneumonia. Unlike cefdinir, amoxicillin is also commonly used to treat gonorrhea and H. pylori infections.
| Condition | Cefdinir | Amoxicillin |
| Acute otitis media | Yes | Yes |
| Chronic bronchitis | Yes | Yes |
| Sinusitis | Yes | Yes |
| Pharyngitis/Tonsillitis | Yes | Yes |
| Community-acquired pneumonia | Yes | Yes |
| Skin and soft tissue infections | Yes | Yes |
| Gonorrhea | No | 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, Escherichia coli, Helicobacter pylori, and Neisseria gonorrhoeae.
Clinical Trials
There are not many strong studies that have been performed to show a direct comparison of cefdinir and amoxicillin. However, some multicenter clinical trials in the United States and Europe have shown that cefdinir and amoxicillin/clavulanate are similar in effectiveness. When treating bacterial sinusitis, cefdinir was just as effective as amoxicillin/clavulanate after 10 days of treatment.
In another study, the tolerability of cefdinir and amoxicillin/clavulanate liquid suspensions were compared in pediatric patients. In a sample of 715 young children four to eight years old, 85% of them rated the taste of cefdinir as good or really good compared to 63% of them who rated amoxicillin/clavulanate, cefprozil, and azithromycin the same.
The effectiveness of these antibiotics will depend on which bacteria is causing the infection. Talk to your doctor or healthcare provider about which antibiotic will work best for you. Because of growing antibiotic resistance, it’s important that an antibiotic is only used after determining the susceptible bacteria causing the infection.
Coverage and cost comparison of cefdinir vs. amoxicillin
As generic antibiotics, cefdinir and amoxicillin are widely available. Almost all Medicare Part D and insurance plans will cover cefdinir and amoxicillin. The typical retail cost of generic cefdinir more than $100. With a SingleCare coupon, this cost can be reduced to less than $25 for a 10-day supply of 300 mg capsules.
Amoxicillin is available in generic and brand-name versions. The average cost of generic amoxicillin capsules is around $24. Using a SingleCare discount card can lower the price to around $5 for a 10-day supply of 500 mg capsules.
| Cefdinir | Amoxicillin | |
| Typically covered by insurance? | Yes | Yes |
| Typically covered by Medicare? | Yes | Yes |
| Standard dosage | 300 mg tablets (quantity of 20) | 500 mg tablets (quantity of 20) |
| Typical Medicare copay | $0–$49 | $0–$10 |
| SingleCare cost | $24-$63 | $5+ |
Common side effects of cefdinir vs. amoxicillin
The most common side effects associated with cefdinir and amoxicillin are diarrhea, nausea, and vomiting.
Amoxicillin is more likely to cause headache when taken with clarithromycin and lansoprazole for H. pylori infections. Amoxicillin may also have a higher incidence of rash after taking it.
More serious side effects of cefdinir and amoxicillin include allergic or hypersensitivity reactions. If you experience adverse events like trouble breathing or severe rash, seek medical attention immediately.
| Cefdinir | Amoxicillin | |||
| Side effect | Applicable? | Frequency | Applicable? | Frequency |
| Diarrhea | Yes | 15% | Yes | >1% |
| Nausea | Yes | 3% | Yes | >1% |
| Vomiting | Yes | 0.7% | Yes | >1% |
| Headache | Yes | 2% | Yes | 6% |
| Rash | Yes | 0.9% | Yes | >1% |
This may not be a complete list. Consult your doctor or pharmacist for possible side effects.
Source: DailyMed (Cefdinir), DailyMed (amoxicillin)
Drug interactions of cefdinir vs. amoxicillin
Cefdinir interacts with antacids as well as iron supplements. Antacids and iron supplements can lower the absorption of cefdinir and decrease its effectiveness. Cefdinir should be taken at least two hours before or after administering these other medications.
Both cefdinir and amoxicillin can interact with anti-gout medications like probenecid and allopurinol. Anti-gout agents can increase the blood levels of cefdinir and amoxicillin, which can lead to increased side effects.
Cefdinir and amoxicillin have been known to cause prolonged prohrombin time in those who are also taking warfarin. This drug interaction can cause an increased risk of bleeding.
Antibiotics have been known to decrease the effectiveness of oral contraceptives. Alternate birth control methods may be needed to reduce the risk of pregnancy.
| 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 |
| Ethinyl estradiol Levonorgestrel Norethindrone |
Oral contraceptives | Yes | Yes |
This may not be a complete list of all possible drug interactions. Consult a doctor with all the medications you may be taking.
Warnings of cefdinir and amoxicillin
Cefdinir and amoxicillin should be avoided if you have a penicillin allergy. Because these drugs are chemically similar to penicillin, they may cause a severe allergic reaction if you have an established penicillin allergy.
Diarrhea is one of the most common side effects of antibiotics like cefdinir and amoxicillin. These antibiotics can also increase the risk of a more severe type of diarrhea caused by Clostridium difficile. If you have a medical history of C. diff infections, the use of these antibiotics may need to be monitored or discontinued.
These antibiotics should only be prescribed for infections caused by bacteria. They are not effective against viral infections such as COVID-19. Cefdinir and amoxicillin are most effective when they are targeting susceptible bacteria. If they are used inappropriately, the bacteria can gain antibiotic resistance and cause a more severe infection.
Frequently asked questions about cefdinir vs. amoxicillin
What is cefdinir?
Cefdinir is a third-generation cephalosporin that is used to treat bacterial infections like acute otitis media and pharyngitis. It is also FDA-approved to treat certain skin infections and lower respiratory tract infections. Cefdinir is also known by its brand name Omnicef.
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, H. pylori infections, and gonorrhea. 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 an umbrella 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 better for H. pylori infections. However, some people may prefer cefdinir in a once-daily option for other infections.
Can I use cefdinir or amoxicillin while pregnant?
There have been no adequate clinical studies to show that cefdinir or amoxicillin are safe while pregnant. They are both deemed Pregnancy Category B drugs, which indicates a low risk for birth defects. 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.
