Your guide to clindamycin for UTI

In this article:

• Clindamycin for UTI
• How clindamycin works
• Why isn’t it a first-choice treatment?
• When might a doctor prescribe clindamycin
• Risks of using the wrong antibiotic
• What to do if you suspect a UTI

In this article

• Clindamycin for UTI
• How clindamycin works
• Why isn’t it a first-choice treatment?
• When might a doctor prescribe clindamycin
• Risks of using the wrong antibiotic
• What to do if you suspect a UTI

Bacteria cause the vast majority of urinary tract infections (UTIs), most commonly Escherichia coli (E. coli). Antibiotics, a class of medications that target and kill bacteria, are often among the first-line treatments for UTIs. However, not all antibiotics are very effective for UTI.

Clindamycin, commonly sold under the brand name Cleocin, is a prescription antibiotic that is FDA approved for the treatment of Streptococcal, anaerobic, and staphylococcal infections. Clindamycin is not among the preferred antibiotics for treating UTIs, and your healthcare provider will most likely not prescribe it for a typical UTI infection. Here’s why.

Can clindamycin treat a UTI?

“Clindamycin is not a standard or recommended treatment for urinary tract infections, and the FDA has not approved its use in UTI treatment,” says Steven Goldberg, MD, MBA, Chief Medical Officer at HealthTrackRx, and a family medicine healthcare provider at UofLHealth in Louisville, Kentucky. 

Clindamycin is not recommended for UTIs because it does not work well against the bacteria that cause most of these infections. According to Dr. Goldberg, more than 75% of UTIs are caused by E. coli, a type of bacteria that clindamycin is not effective at treating. Instead, clindamycin works better against other kinds of bacteria that are usually linked to skin, throat, or dental infections, not urinary tract infections.

In addition, “clindamycin does not concentrate well in the urine, which limits its effectiveness for treating infections in the urinary tract,” says Reshma Kapadia Patel, a Pharm.D. in Dallas, Texas, and the founder of WiseMedRx. Therefore, healthcare professionals typically prescribe other antibiotics that are more effective against E.coli.

Understanding how clindamycin works

Clindamycin works by preventing bacteria from making the proteins they need to grow and multiply, helping the body fight off the infection. Depending on the infection site, the type of bacteria, and its concentration, clindamycin either causes death of the bacteria (bactericidal) or slows the bacteria from growing and multiplying (bacteriostatic).

“When we talk about bacteria, they are often classified as gram-positive or gram-negative based on their cell structure. Gram-positive bacteria have a simpler outer layer, while gram-negative bacteria have an additional outer membrane that can make them harder for certain antibiotics to penetrate,” Dr. Patel says. Gram-negative bacteria cause most UTIs, and since clindamycin is more effective against gram-positive bacteria, it’s often not the right match. 

Why is clindamycin rarely the first choice for UTIs?

There are three main reasons why clindamycin is rarely the first choice of medication for treating UTIs: the bacteria it targets, its poor urinary concentration, and its side effects.

Effectiveness against gram-negative bacteria 

The bacteria that cause most UTIs (E. coli, Proteus, and Klebsiella) are gram-negative organisms, and clindamycin is not effective against them. Dr. Goldberg explains that healthcare providers often use first-line UTI antibiotics such as Macrobid (nitrofurantoin), Bactrim (trimethoprim-sulfamethoxazole), and fosfomycin to treat UTIs because they reliably kill these common bacteria.

The localization issue

“For an antibiotic to effectively treat a UTI, it needs to reach high concentrations in the urinary tract,” says Dr. Patel. Clindamycin is processed primarily by the liver and distributed throughout the body, but only a small amount is excreted into the urine in its active form.

She explains that because clindamycin doesn’t concentrate well in the urine, it may not deliver enough medication to the site of infection to fully clear it. For a UTI, the antibiotic has to reach the urinary tract in sufficient amounts, and clindamycin simply doesn’t localize well there. 

Significant gut side effects

Additionally, healthcare providers may also consider the side effects of clindamycin before prescribing it for UTI. Dr. Goldberg says taking clindamycin carries a well-known risk of disrupting the gut microbiome by killing many of the beneficial anaerobic bacteria that normally inhabit the intestines. This allows a dangerous bacterium, Clostridioides difficile (C. diff), to overgrow and produce toxins.

“Clostridioides difficile infection is an infectious diarrhea that can be very problematic,” says Dr. Goldberg, adding that it can cause symptoms ranging from mild diarrhea to severe, life-threatening colitis. “In fact, the FDA label for clindamycin includes a boxed warning, the most serious type of safety alert, about this risk.” This makes it a poor trade-off for an infection that has safer, more effective treatment options.

When might a healthcare provider prescribe clindamycin for urinary issues

According to Dr. Patel, in certain rare circumstances, clindamycin could be considered for treating UTIs. Examples include:

• If a urine culture identifies that an unusual gram-positive organism (such as certain Staphylococci) is involved in the urinary tract infection
• If the test shows that the particular bacteria causing the infection are susceptible to clindamycin and resistant to standard UTI antibiotics
• If a patient cannot tolerate first-line antibiotics due to allergies or side effects

Dr. Goldberg explains that there is no guideline from any major infectious disease society recommending clindamycin for UTI treatment, and that even in uncommon scenarios, other antibiotics would typically be preferred. The decision to prescribe clindamycin would be culture-guided, off-label, and made on a case-by-case basis.

The risks of using the wrong antibiotic

The wrong use of antibiotics for treating UTIs or other infections can cause serious health risks:

• Antibiotic resistance: Antibiotic resistance occurs when microorganisms develop the ability to survive and defeat the drugs designed to kill them. This can make it more difficult to treat infections affecting not only you but also others, and can cause extended hospital stays (for those hospitalized).
• Secondary infection: Using antibiotics incorrectly can increase the risk of recurrent infections, as the initial antibiotics you took may now make your body more susceptible to the disease. 
• Prolonging infection: When microorganisms become resistant to the antibiotics used to kill them, infections become harder to treat, prolonging illness. 
• Adverse effects: Using antibiotics that are not appropriate for you can also increase the risk of both mild and serious side effects. It can also increase the risk of allergic reactions to ingredients the medication is formulated with.

What you should do

To protect yourself and reduce the risk of dangers associated with antibiotic resistance, consider doing the following:

• Take antibiotics only as prescribed by your healthcare provider.
• Always finish the full course of your antibiotics, i.e., take them for the duration of time your provider instructs, even if you feel better after taking a few doses.
• Do not take antibiotics unless necessary.
• Do not share your antibiotics with others.

What to do if you suspect you have a UTI

If you are experiencing classic UTI symptoms like burning with urination, a frequent or urgent need to urinate, or lower abdominal/pelvic pressure, it’s best to speak with a healthcare provider. “For most otherwise healthy, non-pregnant women with straightforward symptoms and no vaginal discharge, a provider can often diagnose and treat a UTI based on symptoms alone, without requiring a urine culture,” says Dr. Goldberg. The healthcare provider can commence treatment right away.

However, Dr. Goldberg points out that a urine culture may be recommended in certain situations, such as:

• When there are recurrent UTIs (multiple infections in a short period)
• When you have received recent antibiotic treatment for a UTI or have a history of resistant bacteria
• When you are experiencing symptoms that do not improve after starting antibiotics
• When symptoms are atypical or unclear
• When a person assigned male at birth is experiencing UTI symptoms
• For pregnant and breastfeeding individuals
• For adults 65 years and older

A urine culture identifies the exact bacterium causing the infection and which antibiotics it is susceptible to, allowing the provider to tailor treatment and also recommend a different antibiotic if the initial one is not working.

While waiting for your test results, you can do the following to help manage your symptoms and to feel better:

• Drink lots of water to hydrate and help flush out harmful bacteria.
• Do not hold back pee. Use the toilet whenever you feel the urge to urinate.
• Consider applying heat using a mildly hot heating pad, a hot water bottle, or a warm shower. This may help relieve pain in the pubic area.
• Consider taking probiotic supplements.
• Eat foods that can boost your immune system, including vegetables, soups, and broths. Garlic and cranberries have gained some recognition among researchers for their antimicrobial properties and potential use as remedies for UTIs.

Dr. Goldberg advises that you seek urgent or emergency care if UTI symptoms are accompanied by fever, back or flank pain, nausea/vomiting, or feeling very ill, as these may indicate a kidney infection (pyelonephritis) or a more serious condition requiring prompt medical attention.