Ciprofloxacin vs. amoxicillin: Differences, similarities & side effects

In this article:

• Key differences
• Conditions treated
• Which is better?
• Insurance coverage and cost
• Side effects
• Interactions
• Warnings

In this article

• Key differences
• Conditions treated
• Which is better?
• Insurance coverage and cost
• Side effects
• Interactions
• Warnings

When you’re sick, your healthcare provider might prescribe antibiotics to help clear your bacterial infection and help you feel better. Two common antibiotics are ciprofloxacin and amoxicillin. These medicines fight different types of infections by killing bacteria in your body. Ciprofloxacin is part of the fluoroquinolone drug class, while amoxicillin belongs to the penicillin family. Both are available as generic drugs, which means they’re usually less expensive than brand-name medicines. While they’re both used to treat infections, they work in different ways and are used for various illnesses. Let’s take a closer look at how these two antibiotics compare.

Ciprofloxacin vs. amoxicillin: Key differences

Ciprofloxacin and amoxicillin are both antibiotics, but they have some important differences. 

Amoxicillin is used to treat ear, nose, throat, sinus, lower respiratory tract, skin, and urinary tract bacterial infections. As a penicillin antibiotic, it kills bacteria by blocking their ability to make and repair their protective cell walls, which leads to the death of bacteria. People taking amoxicillin may experience minor side effects, such as gastrointestinal upset, but serious side effects and drug interactions with existing medical conditions are also possible. Amoxicillin is a generic drug that’s available as brand-name Amoxil. It is also one of the active ingredients of a brand-name drug called Augmentin (amoxicillin-clavulanate). However, Augmentin is not exactly the same as amoxicillin. It is amoxicillin plus the extra ingredient clavulanate. Healthcare providers sometimes prescribe Augmentin for certain infections because the combination of amoxicillin and clavulanate helps prevent antibiotic resistance. For the purposes of this article, we’ll be comparing amoxicillin, not Augmentin, to ciprofloxacin.

Ciprofloxacin is a generic antibiotic also available under the brand name Cipro. Ciprofloxacin is a broad-spectrum antibiotic that can fight many different types of bacteria. It’s often used for more severe infections or when other antibiotics haven’t worked. It blocks specific enzymes that allow bacteria to grow and multiply. Ciprofloxacin is typically taken by mouth in tablet or liquid form, but it is also available as an injection and as drops for the eye or ear.

Compare ciprofloxacin vs. amoxicillin key differences
	Ciprofloxacin	Amoxicillin
Drug class	Fluoroquinolone antibiotic	Penicillin antibiotic
Brand/generic status	Generic	Generic
What is the brand name?	Cipro and Ciloxan (eye ointment and eye drops)	Amoxil
What form(s) does the drug come in?	Tablets, extended-release tablets, liquid, injection	Capsules, tablets, chewable tablets, liquid
What is the standard dosage?	250–750 mg twice daily (depending on infection)	Varies based on the type of infection; a typical adult dose may be 500 mg by mouth 3 times a day, or 875 mg by mouth every 12 hours
How long is the typical treatment?	3–14 days (depending on infection); sometimes longer for more severe infections	7–14 days (depending on infection)
Who typically uses the medication?	Adults and children (with caution in children)	Adults and children of all ages

Ciprofloxacin vs. amoxicillin: Conditions treated

Ciprofloxacin and amoxicillin are used to treat different types of bacterial infections. Ciprofloxacin is approved by the Food and Drug Administration (FDA) to treat bacterial infections, including: 

• Urinary tract infections
• Kidney infections (pyelonephritis)
• Cystitis (not a first-choice treatment)
• Chronic bronchitis
• Acute sinusitis
• Bone and joint infections
• Prostatitis
• Pneumonia
• Gonorrhea
• Cutaneous or systemic anthrax (post-exposure prophylaxis)
• Typhoid fever
• Salmonella

Ciprofloxacin is often used for more serious infections or when other antibiotics haven’t worked. 

Amoxicillin is commonly used for various bacterial infections. It is FDA approved to treat bacterial infections of the ear, nose, throat, sinuses, lower respiratory tract, skin, skin structures, and urinary tract. It is also key to eradicating Helicobacter pylori (H. pylori) in people with stomach or intestinal ulcers. Dentists commonly use it off-label to treat periodontitis, a severe gum disease. 

It’s important to note that neither ciprofloxacin nor amoxicillin can cure or should be used to treat viral infections like the common cold or flu. They only work against certain types of bacterial infections.

Compare ciprofloxacin vs. amoxicillin conditions treated
Condition	Ciprofloxacin	Amoxicillin
Urinary tract infections	Yes	Yes
Respiratory tract infections	Yes (some types)	Yes
Skin infections	Yes	Yes
Ear infections	Off-label use	Yes
Strep throat	No	Yes
Anthrax	Yes	No
Typhoid fever	Yes	No
Pneumonia	Yes (some types)	Yes (some types)
Bronchitis	Off-label use	Yes
Dental infections	Off-label use	Yes
Urinary tract infections	Yes	Yes

Ciprofloxacin vs. amoxicillin: Which is better?

The effectiveness of ciprofloxacin and amoxicillin depends on the type of infection being treated. Your healthcare provider will choose the most effective medication based on factors such as:

• The type of infection you have
• How severe your infection is
• Your overall health
• Other medications you’re taking
• Your history of antibiotic use
• Any allergies to medications
• Local patterns of antibiotic resistance

Ciprofloxacin vs. amoxicillin: Insurance coverage and cost comparison

Insurance plans and Medicare Part D usually cover both ciprofloxacin and amoxicillin. The cost can vary without insurance depending on the pharmacy and the specific dose. You can save money on these prescriptions by using SingleCare coupons. 

Compare ciprofloxacin vs. amoxicillin cost and coverage
	Ciprofloxacin	Amoxicillin
Typically covered by insurance?	Yes	Yes
Typically covered by Medicare Part D?	Yes	Yes
Quantity	14, 500 mg tablets	21, 500 mg capsules
Average cost without insurance*	$64	$20
SingleCare cost*	$5 with coupon	$5 with coupon

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

Ciprofloxacin vs. amoxicillin side effects

Both ciprofloxacin and amoxicillin can cause side effects, although many people take these antibiotics without any problems. Common side effects of both antibiotics include:

• Nausea
• Vomiting
• Diarrhea
• Rash

Ciprofloxacin has some unique potential side effects. It can sometimes cause tendon damage, especially in older adults or people who are also taking steroid medications. In rare cases, it might also affect the nervous system, causing dizziness or confusion. It can also cause abnormal liver function test results. Serious side effects include peripheral neuropathy, tendinitis, tendon rupture, arrhythmia, QT interval prolongation, jaundice, and allergic reactions.

Amoxicillin can cause allergic reactions in people who are sensitive to penicillin antibiotics. This can range from a mild rash to a more severe allergic response. 

Both Cipro and amoxicillin can cause serious side effects that require emergency medical attention, including:

• Severe, bloody, or watery diarrhea, stomach cramps, or fever
• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, or trouble breathing
• Blistering, peeling, or red skin rash

Ciprofloxacin and amoxicillin drug interactions

Both ciprofloxacin and amoxicillin can interact with other medications, but they interact with different drugs in different ways. Ciprofloxacin has more drug interactions to be aware of. It can affect how your body processes certain medications, for example, potentially causing more serious side effects of other medications you’re taking. For example, ciprofloxacin can increase the effects of drugs that thin your blood, such as warfarin, which could increase the risk of bleeding. Ciprofloxacin interacts with certain medications, such as duloxetine, tizanidine, and theophylline. 

Amoxicillin also has some drug interactions that are important to be aware of. For example, amoxicillin may also interact with oral anticoagulants, such as warfarin, which could lead to a risk of bleeding. Close monitoring and adjustments in the dose of the oral anticoagulant may be necessary to maintain the desired blood levels. Blood level concentrations of amoxicillin can be higher if taken with probenecid, a pill used to prevent gout, which could lead to increased side effects of amoxicillin. Taking allopurinol, another gout-prevention medicine, and amoxicillin together may increase the incidence of skin rashes or hives.

Always tell your healthcare provider about your full medical history, allergies to medications, and all of the medicines you take, including prescription medicines, over-the-counter drugs, vitamins, and dietary supplements.

Compare ciprofloxacin vs. amoxicillin drug interactions
Drug	Drug class	Ciprofloxacin	Amoxicillin
Warfarin	Blood thinner	Yes	Yes
Methotrexate	Used for cancer and certain autoimmune conditions	Yes	No
Tizanidine	Muscle relaxant	Yes	No
Allopurinol	Gout medication	No	Yes
Probenecid	Gout medication	Yes	Yes

Ciprofloxacin and amoxicillin drug warnings

Both ciprofloxacin and amoxicillin have some important warnings to be aware of. Both medicines can cause diarrhea. Call your healthcare provider if the diarrhea becomes severe, does not stop, or is bloody. Do not take any medicine to stop diarrhea until you have talked to your healthcare provider. Diarrhea can occur two months or more after you stop taking either drug.

Ciprofloxacin drug warnings:

• The FDA has issued a boxed warning (its strongest warning) for ciprofloxacin and other fluoroquinolone antibiotics. This warning states that these drugs can increase the risk of tendon rupture, especially in older adults or people taking steroid medications. It is contraindicated (should not be used) in individuals with fluoroquinolone hypersensitivity or myasthenia gravis. Use is restricted or discouraged unless no other treatment options exist in individuals who:
  • Are over 60 years old
  • Have a history or high risk of aortic aneurysm, peripheral atherosclerotic vascular disease, hypertension, or conditions like Marfan or Ehlers-Danlos syndrome
  • Are being treated for acute bacterial exacerbations of chronic bronchitis, uncomplicated UTIs, or acute bacterial sinusitis
• Ciprofloxacin may increase the risk of a type of irregular heartbeat called QT prolongation in some people.
• Ciprofloxacin isn’t usually recommended during pregnancy unless a healthcare provider determines that the benefits outweigh the risks.

Amoxicillin drug warnings:

• People with penicillin allergies should only take amoxicillin after talking to their healthcare provider first.
• Amoxicillin can cause a false positive result on specific diabetes urine tests.
• Amoxicillin is generally considered safe during pregnancy, but you should always discuss this with your healthcare provider.
• Before taking amoxicillin, tell your healthcare provider if you have:
  • Kidney disease
  • Drug allergies

Neither ciprofloxacin nor amoxicillin is habit-forming, and they don’t cause withdrawal symptoms when you stop taking them. However, it’s important to finish your entire course of antibiotics as your healthcare provider prescribes, even if you start feeling better.

Medication decisions should always be made in consultation with a healthcare provider. The most effective treatment for any patient depends on their medical history, current condition, and potential drug interactions. Only a healthcare provider can determine whether ciprofloxacin, amoxicillin, or another medication is appropriate, based on the patient’s unique health profile and response to treatment. Always follow your healthcare provider’s advice about which antibiotic to use and how to take it.