Facts About Urinary Tract Infections

Urinary Tract Infections (UTI) are associated with symptoms such as frequent urination, urgent need to urinate or pain. If you do not have symptoms you should not be treated for an infection (unless you have a special situation such as pregnancy or are undergoing certain surgeries). In older people, changes in behavior or mental status are not usually reasons to start taking an antibiotic unless there are bladder symptoms such as pain or frequent urination. Cloudy or bad-smelling urine without any other symptoms is not a reason to be treated with antibiotics. Treatment with with an antibiotic when you don’t have an infection may make you more likely to have an infection in the future. 

Most people without any bladder symptoms should not be treated for a UTI just because a urine test suggests an infection. Notable exceptions include women who are pregnant and patients who are having certain kinds of surgery. A positive urine test may indicate asymptomatic bacteriuria - a term that simply means having bacteria in your urine without an infection. It is not uncommon, particularly in older women, to have this type of bacteria, without any symptoms. Treating asymptomatic bacteriuria with antibiotics is associated with a greater risk of infection in the future.

There are several important factors that influence antibiotic choice in bladder infections. One of the first is whether you have allergies to certain antibiotics. It is important to remember that an allergy is not the same as a side effect (such as upset stomach, diarrhea, etc) that some people have with antibiotics. Another concern is how resistant certain bacteria are to different antibiotics in your region. A urine culture can help to clarify the type of bacteria infecting you and what drugs it may be sensitive to (though it can take a few days to get a result). Another important consideration is the risk that some antibiotics can create other problems, including a serious complication called C. difficile colitis. Certain antibiotics such as ciprofloxacin and levofloxacin also carry risks and should not be prescribed for most bladder infections unless the bacteria are resistant to other antibiotics or you have many antibiotic allergies.

Unless one of the above factors overrides the decision, the most appropriate antibiotics to be tried first in otherwise uncomplicated UTI are nitrofurantoin (Macrobid), sulfamethoxazole/trimethoprim (Bactrim), and fosfomycin (Monurol). Why these particular antibiotics? First, they are effective at treating UTI, with studies showing from 83%-100% cure rate. Second, they cause less collateral damage compared with other antibiotic choices. Alternative antibiotic (second-line) choices can certainly be used when drug allergies or information about bacterial resistance dictates. Ciprofloxacin and levofloxacin are antibiotics frequently used to treat UTI but are not on the list of first-line therapies. Why not? Because these antibiotics carry risks of nervous system disorder, tendon rupture, aortic rupture, and heart rhythm disturbances that generally outweighs the benefit in uncomplicated urinary tract infection unless other antibiotics are not indicated.

Finally, it should be noted that shorter courses of antibiotics do not result in as many side effects such as upset stomach or diarrhea. In addition, it is possible that longer courses of antibiotics may do additional damage to the normal, healthy bacteria that coexist in our bodies and may provide benefits. For this reason, you should generally take as short of a course of antibiotics as possible for an uncomplicated bladder infection. An appropriate course would rarely be longer than a week and frequently would be shorter.

For people without complications, not treating a UTI with antibiotics may prolong symptoms (some studies suggest by only a day), but these rarely progress to more serious infections.  Normal bladder bacteria, which are harmed by antibiotic use, play an important role in normal bladder health including preventing infections.  It is important to avoid antibiotic use if you don’t have symptoms of an infection. If you have symptoms of a UTI and find them getting worse or not improving after a couple of days, it is advisable to consider antibiotic therapy. There are some patients, particularly the elderly, who may be at higher risk for not treating a symptomatic UTI right away.

Remember, even if you are told by your health provider that you have an abnormal urine test, that does not mean you should be treated for a UTI unless you have symptoms (unless you are pregnant or are having certain kinds of surgery). If you are having symptoms, you will probably be given an antibiotic to treat the infection. Most antibiotic treatments for bladder infections in women should last 3-5 days. Longer courses of antibiotics do not result in greater effectiveness but may result in greater harm to normal bladder bacteria. In certain patients who have complicating factors (this probably includes all men) a longer course of antibiotics such as 7 days is often used. Patients with infections that have spread to the kidneys are usually treated for 10-14 days.

Recurrent Urinary Tract Infections

Recurrent Urinary Tract Infections can be one of the most frustrating problems faced by patients (these can occur in men but are more common in women). Those who experience at least 3 urinary tract infections in a year or at least 2 over six months are said to have recurrent Urinary Tract Infections (rUTI). These infections should be associated with bladder symptoms such as frequent urination, urgency urination, bladder pain or pain with urination. Bacteria in the bladder which does not cause any symptoms is called asymptomatic bacteriuria and should not be treated as a UTI.

Unfortunately, many other bladder diseases can cause similar symptoms to UTI and can easily be confused. Interstitial Cystitis (Bladder Pain Syndrome), bladder stones, Overactive Bladder, and even some types of bladder cancer can cause symptoms similar to UTI. Urine cultures can be useful if there is a suspicion that another disease is causing the symptoms. However, it is possible to have both an infection and another of these issues so patients with recurrent UTI may need further evaluation such as imaging of the kidneys or a look into the bladder with a small scope.

The first step in evaluating someone who reports recurrent UTI is to be sure that they 1) have symptoms of a UTI and 2) that these symptoms correspond to bacteria in the urine. This may sound obvious but it is often ignored. Both have to be present if patients are having recurrent infections.

Many patients with recurrent urinary tract infections will not need any more of an evaluation than a patient history, physical exam and a check of their urine. We do not routinely perform invasive testing on patients with recurrent infections.

However, there are certain situations in which a more in-depth evaluation is appropriate. This may include an ultrasound or CT of the kidneys as well or looking into the bladder with a small scope. A patient who continues with a urinary tract infection despite treatment with an appropriate antibiotic or a patient who has a rapid re-infection after treatment could have an abnormality of the urinary tract such as a stone or diverticulum (small pocket) and should be checked for this. Those with previous pelvic surgery or radiation will often need to have the inside of the bladder checked with a scope to be sure that no underlying abnormality is leading to complicated urinary tract infections.

As discussed above, in patients with a complicated history such as pelvic surgery or radiation or those patients who have rapid return to infection after treatment, an evaluation to check for underlying bladder problems such as bladder stones is often appropriate. However, if no such abnormalities are found, there are numerous steps that can be taken to reduce the frequency of recurrent UTI.

Cranberry Juice and Extracts

Cranberry has been extensively studied as a way of reducing the frequency of infections. The active chemicals are thought to be proanthocyanidins (PAC), which may bind to infection-causing bacteria and prevent them from adhering to the bladder. It is reasonable for patients worried about infections to use this as a preventative with important limitations. Cranberry juice can be high in sugar which may cause problems in diabetics. Cranberry cocktails that contain only a portion of cranberry juice, often do not contain enough PAC to have the intended effect. Unfortunately, many people do not like the taste of pure cranberry juice. Some people who do not like cranberry juice will take cranberry extract tablets or capsules. While there are studies showing effectiveness of cranberry extract, in these studies, the extracts contained very specific amounts of PAC. Unfortunately, there is no regulation on the amount of PAC for commercial cranberry extract and one study found a huge variability in the amount of this active ingredient from one brand to another (and even differences within the same brand). Thus, it is difficult to recommend cranberry extracts when you cannot be certain how much of the active ingredient you may be getting.

Probiotics

There is considerable popularity in using probiotics (or bacteria strains thought to be beneficial) to prevent UTI though there are relatively few studies that show a benefit. Many of these studies used probiotics applied directly to the vagina. Most people who take probiotics take them by mouth and it is unclear if the same benefits come from taking them this way. Vaginal suppository probiotics which contain the likely helpful strains can be difficult to locate. There is one study which found that an oral probiotic containing specific strains of bacteria (Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14) were as helpful as taking a daily antibiotic (Bactrim). The results of these studies are not entirely clear and can be contradicting. I don’t automatically recommend probiotics to my patients with recurrent UTI but I also do not discourage them either. If a patient wishes to take a probiotic, I usually recommend one which contains the specific strains of bacteria mentioned above.

D-mannose

D-mannose is a sugar, taken by mouth which is then secreted into the urine and is thought to bind to certain types of bacteria in a way which would prevent adherence to the bladder. D-mannose is well tolerated and I have noted few reported side effects in patients taking this. There are studies showing D-mannose is as effective at reducing the number of infections as a low-dose antibiotic. D-mannose is thought to have less of an effect on normal bladder bacteria than antibiotics taken for prevention of infections. I view D-mannose somewhat similarly to probiotics. It is very unlikely to be harmful (the small amount of sugar is too small to have much of an effect on diabetics) and there is at least some evidence that it is beneficial. It is also fairly inexpensive and widely available both in retail locations as well as online. Because it appears reasonably effective, demonstrates very few side effects and is relatively low-cost, I recommend D-mannose to almost all of my recurrent UTI patients initially.

Antibiotics

There is no shortage of studies demonstrating that a continuous, often low, dose of antibiotics can reduce the frequency of recurrent urinary tract infections. Using antibiotics this way is called prophylaxis. The most extensively studied and most commonly used of these are nitrofurantoin and trimethoprim (though there are limited studies on others). Of note, ciprofloxacin is not an appropriate prophylaxis agent.

There are risks of side effects with these longer courses of antibiotics with stomach upset and diarrhea being the most common. A smaller number of patients may see rashes or other skin reactions. There is a very small risk of lung damage from long-term use of nitrofurantoin so you should probably avoid it as prophylaxis if you have a chronic lung disease such as chronic obstructive pulmonary disease (COPD). Antibiotic resistance resulting from these longer courses has not been studied, However, since antibiotic resistance is more likely even with short courses of antibiotics, it is almost certainly increased using antibiotics for prophylaxis. This should be factored into the decision to use antibiotics in this way. In my practice, I still occasionally utilize antibiotic prophylaxis but generally only for those who continue have recurrent UTI despite non-antibiotic measures.

There is no clear guidance on how long antibiotic prophylaxis should last. Typically, this is done for 3-6 months, though some people are placed on antibiotic prophylaxis for years. While it is unclear if these very long prophylactic courses cause any harm, it should be noted that there is no real evidence to support this practice. A final type of prophylaxis is intended for women who reliably report UTI associated with intercourse. A post-coital prophylaxis dose can be taken immediately before or after intercourse and has been shown to significantly reduce the frequency of recurrent urinary tract infections.

Estrogen

Estrogen therapy can be either systemic (a pill or patch delivering estrogen by blood to the entire body) or vaginal (a cream or ring meant to deliver estrogen only to the vaginal tissues). The risks and benefits of these two types of estrogen are very different. Vaginal estrogen does not have many of the benefits of systemic estrogen (such as helping with hot flashes) but also does not carry many of the cardiovascular risks of systemic estrogen. Vaginal estrogen is not readily absorbed into the rest of the body and breast cancer survivors can discuss its use with their oncologists, as it appears largely safe.

Vaginal estrogen therapy, which replaces the effects of estrogen on the vaginal tissues, reduces the risk of recurrent UTI in menopausal women. Women who are near or past menopause and experience recurrent UTI should consider using vaginal estrogen therapy to reduce their risk of infections. There does not appear to be a similar benefit from using estrogen pills or patches. In fact, women who are already on systemic estrogen therapy who have rUTI will often benefit from adding a vaginal estrogen cream. I recommend this to many women in my practice. The most common complaint that I hear is the expense of the medication if it is poorly covered by insurance. This can sometimes be lessened by using a compounded estrogen cream. It is also reassuring to remember that while a tube of estrogen cream can be expensive, a single tube will often last many months if used properly (a small amount goes a long way).