{"id":10303,"date":"2020-04-06T09:53:59","date_gmt":"2020-04-06T13:53:59","guid":{"rendered":"https:\/\/www.singlecare.com\/blog\/?p=10303"},"modified":"2026-01-28T13:43:30","modified_gmt":"2026-01-28T18:43:30","slug":"amoxicillin-vs-penicillin","status":"publish","type":"post","link":"https:\/\/www.singlecare.com\/blog\/amoxicillin-vs-penicillin\/","title":{"rendered":"Amoxicillin vs. penicillin: Differences, similarities, and which is better for you"},"content":{"rendered":"

Drug overview & main differences<\/a> | Conditions treated<\/a> | Efficacy<\/a> | Insurance coverage and cost comparison<\/a> | Side effects<\/a> | Drug interactions<\/a> | Warnings<\/a> | FAQ<\/a><\/p>\n

If you\u2019ve ever been sick with a bacterial infection, you may have been prescribed an antibiotic like amoxicillin or penicillin. As penicillin-type antibiotics<\/a>, these drugs are two of the most common antibiotics<\/a> prescribed. Both amoxicillin and penicillin treat similar bacterial infections of the respiratory tract, genitourinary tract, ear, nose, and throat.<\/p>\n

<\/span><\/p>\n

Amoxicillin and penicillin are generic antibiotics that belong to a larger class of antibiotics called beta-lactams<\/a>. These drugs work by blocking the bacteria\u2019s ability to build and maintain their protective structure known as the cell wall. Without the cell wall, the bacteria can\u2019t survive.<\/p>\n

Despite their similar nature, amoxicillin and penicillin can kill different types of bacteria. Because of this, they can be used in different ways.<\/p>\n

What are the main differences between amoxicillin and penicillin?<\/h2>\n

Amoxicillin<\/h3>\n

Amoxicillin is a newer version of penicillin that covers more types of bacteria. Amoxicillin<\/a> was created by modifying the original chemical structure of penicillin to make it more potent.<\/p>\n

Both amoxicillin and penicillin cover Streptococcal bacteria. However, Amoxicillin is considered a broad-range antibiotic that covers a wider variety of bacteria compared to penicillin. Amoxicillin is sometimes combined with a beta-lactamase inhibitor, such as clavulanic acid<\/a>, to make it even more potent.<\/p>\n

Penicillin<\/h3>\n

Because penicillin became one of the most commonly used antibiotics in the world, many bacterial species have gained resistance against it. However, it is still useful for certain bacterial infections.<\/p>\n

Penicillin<\/a> is a narrow-range antibiotic that covers gram-positive bacteria and some gram-negative bacteria. Penicillin can be given as an injection (penicillin G<\/a>) as well as an oral tablet or liquid suspension (penicillin V<\/a>).<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n
Main differences between amoxicillin and penicillin<\/span><\/th>\n<\/tr>\n<\/thead>\n
<\/td>\nAmoxicillin<\/strong><\/td>\nPenicillin<\/strong><\/td>\n<\/tr>\n
Drug class<\/td>\nAntibiotic
\nBeta-lactam<\/td>\n		Antibiotic
\nBeta-lactam<\/td>\n<\/tr>\n
Brand\/generic status<\/td>\nBrand and generic versions available<\/td>\nBrand and generic versions available<\/td>\n<\/tr>\n
What is the brand name?<\/td>\nMoxatag, Amoxil<\/td>\nPfizerpen (penicillin G)<\/td>\n<\/tr>\n
What form(s) does the drug come in?<\/td>\nOral tablet
\nOral tablet, chewable
\nOral capsule
\nOral powder for suspension<\/td>\n		Oral tablet
\nOral powder for suspension
\nIV powder for injection<\/td>\n<\/tr>\n
What is the standard dosage?<\/td>\n500 mg every 12 hours or 250 mg every 8 hours.<\/p>\n

Dosing depends on the infection being treated.<\/td>\n

125 to 250 mg every 6 to 8 hours<\/p>\n

Dosing depends on the infection being treated.<\/td>\n<\/tr>\n

How long is the typical treatment?<\/td>\n7\u201310 days<\/p>\n

Duration depends on the infection being treated.<\/td>\n

2\u201310 days<\/p>\n

Duration depends on the infection being treated.<\/td>\n<\/tr>\n

Who typically uses the medication?<\/td>\nAdults, children, and infants aged 3 months and older<\/td>\nAdults and children aged 12 years and older<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
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Want the best price on amoxicillin?<\/h3>\n

Sign up for amoxicillin price alerts and find out when the price changes!<\/p>\n

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Conditions treated by amoxicillin and penicillin<\/h2>\n

Amoxicillin and penicillin can treat many different bacterial infections including lower respiratory tract infections and dental infections. Amoxicillin and penicillin are commonly prescribed to treat middle ear infections<\/a>, otherwise known as otitis media. Both antibiotics can also treat certain infections of the urinary tract<\/a> and skin.<\/p>\n

Amoxicillin is FDA-approved to treat bacterial infections such as gonorrhea. It can also treat H. pylori<\/em> infections and throat infections like pharyngitis<\/a> and tonsillitis. For respiratory tract infections like community-acquired pneumonia (caused by streptococcus pneumonia<\/em>), amoxicillin is an option in areas with low antibiotic resistance<\/a>.<\/p>\n

Penicillin is often used to treat bacterial endocarditis, scarlet fever<\/a>, and dental infections. Skin infections caused by Staphylococcus aureus<\/em> can also be treated with penicillin, although the penicillin G form is preferred.<\/p>\n

Can amoxicillin and penicillin treat viral infections?<\/h3>\n

It\u2019s important to note that antibiotics including amoxicillin and penicillin are not effective against viral infections such as COVID-19<\/a>. These types of infections are caused by viruses and do not respond to antibiotics. However, viral infections can weaken the immune system and lead to bacterial infections, which may warrant antibiotic treatment.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n
Condition<\/strong><\/td>\nAmoxicillin<\/strong><\/td>\nPenicillin<\/strong><\/td>\n<\/tr>\n
Ear, nose, and throat infections<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Lower respiratory tract infections<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Dental infections<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Genitourinary tract infections<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Skin and soft tissue infections<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Scarlet Fever<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Bacterial endocarditis<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Infections caused by E. coli<\/em>, Salmonella<\/em>, H. influenzae<\/em>, Shigella<\/em><\/td>\nYes<\/td>\nNo<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Is amoxicillin or penicillin more effective?<\/h2>\n

Although both antibiotics are effective for treating bacterial infections, their effectiveness depends on the bacteria causing the infection. Amoxicillin is able to get rid of a broader range of bacteria compared to penicillin. Although both antibiotics are effective against streptococci<\/em>, amoxicillin is more effective against E. coli<\/em> and H. influenzae<\/em>, among others.<\/p>\n

According to a 2018 systematic review<\/a>, amoxicillin is better for treating community-acquired pneumonia compared to penicillin. However, results showed that penicillin may be better for respiratory tract infections in general due to its narrow coverage. There was no significant difference between the two antibiotics when treating otitis media.<\/p>\n

One of the primary goals of fighting bacterial infections is to prevent resistance. Bacterial resistance can lead to stronger infections which can be harder to treat. This is why knowing what bacteria is causing the infection is important. Talk with your healthcare provider to find the best treatment option that works for you.<\/p>\n

Coverage and cost comparison of amoxicillin vs. penicillin<\/h2>\n

Amoxicillin is a commonly prescribed antibiotic that is almost always covered by Medicare and insurance plans. The typical average cost of amoxicillin is around $24. However, a SingleCare discount card <\/a>can lower this cost to around $5. Amoxicillin is usually purchased as a generic tablet, capsule, or oral liquid.<\/p>\n

Like amoxicillin, penicillin is also widely available and covered by most insurance plans. If you are picking up penicillin from the pharmacy, it will most likely be the penicillin V or penicillin VK form. The average cost of penicillin V is $40. However, with a SingleCare discount card, this cost can be lowered<\/a> to around $9. The cost will depend on which pharmacy you use and whether you get the pill or liquid form.<\/p>\n\n\n\n\n\n\n\n\n
\u00a0<\/strong><\/td>\nAmoxicillin<\/strong><\/td>\nPenicillin<\/strong><\/td>\n<\/tr>\n
Typically covered by insurance?<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Typically covered by Medicare?<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Standard dosage<\/td>\n500 mg tablets<\/td>\n250 mg tablets<\/td>\n<\/tr>\n
Typical Medicare copay<\/td>\n$0\u2013$10<\/td>\n$0\u2013$18<\/td>\n<\/tr>\n
SingleCare cost<\/td>\n$5+<\/td>\n$8.80+<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Common side effects of amoxicillin vs. penicillin<\/h2>\n

Amoxicillin and penicillin have similar side effects. The most common side effects of these antibiotics are diarrhea, nausea, and vomiting.<\/p>\n

One difference between amoxicillin and penicillin is that amoxicillin is more likely to produce a skin rash. This rash can range in severity from mild to severe. However, it usually goes away within a few days. Talk to your doctor if you or your child develops a rash.<\/p>\n\n\n\n\n\n\n\n\n
\u00a0<\/strong><\/td>\nAmoxicillin<\/strong><\/td>\nPenicillin<\/strong><\/td>\n<\/tr>\n
Side Effect<\/td>\nApplicable?<\/td>\nFrequency<\/td>\nApplicable?<\/td>\nFrequency<\/td>\n<\/tr>\n
Diarrhea<\/td>\nYes<\/td>\n>1%<\/td>\nYes<\/td>\n*not reported<\/td>\n<\/tr>\n
Nausea<\/td>\nYes<\/td>\n>1%<\/td>\nYes<\/td>\n*<\/td>\n<\/tr>\n
Vomiting<\/td>\nYes<\/td>\n>1%<\/td>\nYes<\/td>\n*<\/td>\n<\/tr>\n
Rash<\/td>\nYes<\/td>\n>1%<\/td>\nNo<\/td>\n–<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

This may not be a complete list. Consult your doctor or pharmacist for possible side effects.<\/em>
\nSource: DailyMed (Amoxicillin<\/a>), DailyMed (Penicillin<\/a>)<\/p>\n

Drug interactions of amoxicillin vs. penicillin<\/h2>\n

Amoxicillin and penicillin can interact with several other medications. Penicillin-type antibiotics may interact with methotrexate<\/a>, a drug often used to treat rheumatoid arthritis. Taking amoxicillin or amoxicillin can affect how the body processes methotrexate, which may lead to toxicity.<\/p>\n

Antigout medications like probenecid<\/a> and allopurinol<\/a> can lead to increased blood levels of amoxicillin or penicillin. This interaction may lead to increased side effects.<\/p>\n

The effectiveness of amoxicillin and penicillin may be reduced when they\u2019re taken with birth control pills<\/a> or other antibiotics.<\/p>\n

Combining amoxicillin or penicillin with warfarin may affect how warfarin is processed in the body. This may result in an increased risk of bleeding.<\/p>\n\n\n\n\n\n\n\n\n
Drug<\/strong><\/td>\nDrug Class<\/strong><\/td>\nAmoxicillin<\/strong><\/td>\nPenicillin<\/strong><\/td>\n<\/tr>\n
Methotrexate<\/td>\nAntimetabolite<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Allopurinol<\/p>\n

Probenecid<\/td>\n

Antigout<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Ethinyl estradiol
\nLevonorgestrel
\nNorethindrone<\/td>\n		Oral contraceptives<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Warfarin<\/td>\nAnticoagulant<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Chloramphenicol
\nErythromycin<\/td>\n		Antibiotics<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

This may not be a complete list of all possible drug interactions. Consult a doctor with all the medications you may be taking. <\/em><\/p>\n

Warnings of amoxicillin and penicillin<\/h2>\n

Serious hypersensitivity and allergic reactions have been reported with amoxicillin and penicillin. Allergic reactions may lead to anaphylaxis<\/a> or anaphylactic shock. If you experience difficulty breathing, severe rash, and severe nausea, seek medical attention immediately.<\/p>\n

If you are prescribed a course of amoxicillin or penicillin treatment, it\u2019s important to finish all of the antibiotics<\/a> even if you\u2019re feeling better. If you don\u2019t finish treatment, the bacteria may have a chance to mutate and develop resistance to the antibiotic. This can lead to a more severe infection that would require further treatment.<\/p>\n

Talk to your doctor if you experience or have a history of the following:<\/p>\n