10 Tips About Cefdinir for UTI

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Planning to take Cefdinir for UTI? In fact, it’s one of the commonest antibiotics to treat many different infections. Moreover, back in 2008, it was the highest selling antibiotics in its class.

Cefdinir belongs to the class of “cephalosporins,” cousins to penicillins and it is a part of the beta-lactam group of antibiotics. You may have heard of another common cephalosporin: Keflex (cephalexin). Keflex is also often prescribed for UTIs but is an older drug than Cefdinir.

#1 Cefdinir or Keflex for UTI?

Cefdinir is considered the 3rd generation cephalosporin, whereas Keflex is only the first generation.

Normally, the later generations are more effective than the earlier generations, because they could fight more types of bacteria.

For example, Cefdinir treats more strains of E.coli, the most common bacteria causing UTIs, than Keflex. Cefdinir is also useful for resistant bugs that Keflex can’t kill.

#2 Do Not Use Cefdinir For An Uncomplicated UTI

Since Cefdinir is a third generation drug, only use it if anything else fails. Ask for an alternative antibiotic, if this is your first or second UTI.

Also, ask your doctor to test your bacteria and see if they are susceptible to other antibiotics before agreeing to take Cefdinir for UTI

That’s because overusing such powerful drugs sets you up for antibiotic resistance. Unfortunately, the reason scientist must engineer newer and “better” antibiotics is because the old ones are no longer effective.

Think of Penicillin, the miracle drug of the 1940s, that saved countless lives by curing infections that modern medicine previously had no way of treating. Sadly, penicillin is rarely used today because the vast majority of infection-causing bacteria are resistant to it; they have learned many tricks to block the effect of Penicillin.

#3 Plan A Hospital Stay, If Cefdinir Doesn’t Work

Because physicians prescribe antibiotics, like Cefdinir too much, we now have to deal with mutants like ESBL E.coli (extended spectrum beta-lactamase E.coli).

ESBL E.coli is a monster resistant to even our strongest antibiotics, including Cefdinir and other beta-lactam antibiotics. This is happening already- there is a growing number of reports of humans dying from so-called “superbugs” resistant to all available antibiotics.

Cefdinir is often used to treat UTI in people who have been exposed to lots of antibiotics, and therefore have more resistant strains of bacteria, that aren’t quite super-bugs.

While Cefdinir should not be prescribed for your first UTI, remember that if you’ve used antibiotics for other reasons- like chronic sinus infections- you may already have resistant bugs in your system! Also, be aware of what you eat- reports suggest that chicken may be causing your resistant UTIs.

As you can imagine, Cefdinir is not fail-proof, since more and more E. coli are becoming resistant to it.

Currently, there are five generations of cephalosporins.  Drugs that belong to 4th and 5th generations are be given intravenously.

Unfortunately, if Cefdinir doesn’t work for you to cure UTI,  next step is a hospital stay and invasive procedures.

#4 Cefdinir Is Not Approved By FDA For UTI

Cefdinir was first FDA approved in 1997 for infections involving the skin, throat, ears, and sinuses.

Cefdinir has been used for many years to treat urine infections as well, although technically it is not approved for this use by the FDA. Despite this, several studies show Cefdinir is able to prevent and treat UTIs – often complicated ones- with great success.  

#5 Cefdinir And Your Microbiome

Cefdinir, like most other antibiotics, kills bacteria, and that means it can affect the friendly bacteria living peacefully in your digestive tract.  

A study showed that a short-term use (4-14 days), does not make a big impact on gut flora. However, the researchers noticed that Cefdinir was found in stool and therefore some of the gut flora developed resistance to Cefdinir.

It’s also important to remember the study didn’t look at chronic or recurring Cefdinir use, which may have a greater impact. Also, some people may be more susceptible, such as older adults or people who already have other medical problems.

Furthermore, a common side effect of cefdinir (like nearly every other antibiotic) is diarrhea, which suggests a change in our gut flora.

It is important to have a healthy microbiome before you start antibiotics and replenish your bacterial guests once you stop the antibiotics. Keeping healthy diet and using microbiome-friendly hygiene products, like this prebiotic Wash, can help to support beneficial bacteria and suppress organisms responsible for infections.

#6 Keep In Mind


  • Be careful if you have a history of a penicillin allergy;  about 10% of people with penicillin allergies also have allergies to cephalosporin. (If you’ve taken any other cephalosporin, you should be fine.)  
  • If you are pregnant or breastfeeding touch base with your doctor before starting the medicine.
  • Also, if you have kidney failure, you will likely need to take a smaller dose or take another antibiotic altogether.  

#7 Cefdinir For UTI: Side Effects

The most common side effects of Cefdinir are:

  • Diarrhea,
  • Vaginal yeast infections,
  • Nausea,
  • Headaches
  • Abdominal pain.

Diarrhea is the most common side effect, with about 15% of people affected, but it generally resolves after you stop the medicine. Most other side effects occur in less than 5% of people.

There are many other rare side effects- several of them serious- but tend to occur in patients with underlying diseases. If you have a serious or chronic medical problem, always let your doctor know before taking Cefdinir.

A spooky side effect that could happen on Cefdinir, especially if you take iron supplements, is red poop. However, this is not dangerous, so don’t be alarmed.

Also, of course, if you have difficulty breathing, shortness of breath, hives, swelling of the throat or other serious side effects, stop the medicine immediately and call your doctor or 911.

#8 Cefdinir Could Cause C. diff Colitis

However, let your doctor know immediately if besides diarrhea you notice other symptoms such as:

  • Fevers/chills,
  • Nausea
  • Bloody stools,

The combination of these symptoms could be a sign of a serious problem like C. diff.  C. diff colitis is a serious gut infection caused by the rise of aggressive gut destroying bugs.

#9 How To Boost Performance Of Cefdinir For UTI 

Several studies show that certain compounds improve the effectiveness of antibiotics. 

Why is this important?

  • Antibiotics alone are not capable of fighting bacterial biofilms
  • You want to get rid of as much harmful bacteria as possible to prevent future antibiotic resistance

N-acetyl cysteine (NAC)

Did you know that NAC has antioxidant and anti-inflammatory properties? And, it may also be antimicrobial and help to disrupt biofilms, the spaces bacteria like to hide out.

NAC is commonly used to improve for respiratory infections because it naturally helps clear mucus and improves symptoms. Importantly, many of the bugs that cause respiratory infections also cause UTIs.

Some studies showing NAC helps to treat UTIs as well.

A small study looking at breast cancer survivors with recurring UTIs showed that a combination of NAC, D-mannose and Morinda citrifolia. D-mannose is a UTI suppressor because it blocks E. coli from attaching to the bladder wall, while Morinda citrifolia (also known as noni) has antibacterial, anti-inflammatory and immunomodulatory effects).

Women who took this combination with antibiotics had fewer UTIs and fewer symptoms over several months. Unfortunately, these studies did not specifically look at Cefdinir, but rather other common UTI antibiotics.

Uva Ursi

Uva ursi is used in its own right to help prevent UTIs, but in combination with antibiotics, it provides an extra punch to eradicate resistance.

A component of uva ursi, corilagin, greatly reduce the amount of a beta-lactam antibiotic (remember, Cefdinir is part of this group) needed to treat an infection.

In the studies, scientists were able to decrease the amount of antibiotic needed by up to 2000 times when they added corilagin.

However, they did these tests in a laboratory, not on people. Therefore, we will have to wait for clinical studies to know for sure.

At the same time, this is really exciting news that should spur studies to find ways to combat increasing antibiotic resistance. It is important to let your doctor know if you are taking uva ursi, as you may need to adjust the dose of your antibiotics.

#10 Recover After Cefdinir: Probiotics

As mentioned above, Cefdinir- and other antibiotics– affect bad and good bacteria alike. That’s why common side-effects include yeast infection and diarrhea.

Therefore, it is important to keep healthy flora at all times, and especially when taking antibiotics.

It’s best to start off with a healthy gut before taking antibiotics and take probiotics to replenish any of your friendly gut guests that may be affected by the antibiotics you take. Remember to focus on probiotics that replenish the gut and vagina flora, such as Lactobacillus and Bifidobacterium.


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