Understanding Statins and UTIs
Statins are a class of drugs known as HMG-CoA reductase inhibitors. They work by blocking a key enzyme the liver uses to produce cholesterol, thereby lowering levels of low-density lipoprotein (LDL), or "bad," cholesterol in the blood. They are a cornerstone of prevention for cardiovascular diseases, including heart attacks and strokes [1.3.1, 1.5.1]. Common statins include atorvastatin (Lipitor), rosuvastatin (Crestor), pravastatin (Pravachol), and simvastatin.
A urinary tract infection (UTI) is an infection in any part of the urinary system, which includes the kidneys, bladder, ureters, and urethra. Most infections involve the lower urinary tract—the bladder and the urethra [1.4.3]. They are typically caused by bacteria, most commonly E. coli, entering the urinary tract [1.4.4].
The Direct Evidence: A Conflicting Picture
The question of whether statins directly cause UTIs does not have a simple answer. The scientific evidence is mixed and appears to vary depending on the specific statin and the patient population.
Evidence for a Causal Link
Some statins explicitly list urinary tract infections as a potential side effect. For example, the prescribing information for atorvastatin (Lipitor) and rosuvastatin (Crestor) includes UTIs as a common or possible side effect [1.7.2, 1.7.3, 1.8.4]. Healthline and the Mayo Clinic also note UTI as a side effect of atorvastatin [1.7.3, 1.7.4]. This indicates that during clinical trials and post-marketing surveillance, a number of patients reported developing UTIs while taking these medications.
Evidence for a Protective Effect
Conversely, some research points in the opposite direction. A 2012 study analyzing data from a trial on pravastatin found that it was associated with a significantly reduced risk for recurrent UTIs, though not for a first-time UTI [1.2.1]. Another study from 2016 concluded that statin initiation was associated with a decreased risk of receiving antibiotic prescriptions (a proxy for infections) among patients with drug-treated type 2 diabetes [1.6.4]. A separate historical cohort study also found that prior therapy with statins was associated with a considerably reduced onset of acute bacterial infections, including acute pyelonephritis (a type of kidney UTI) [1.6.5].
Indirect Connections: Statins and Overall Bladder Health
Beyond a direct link to UTIs, statins may influence urinary health through other mechanisms affecting the bladder.
Lower Urinary Tract Symptoms (LUTS)
The evidence here is also complex. LUTS refers to a range of issues including storage problems (frequency, urgency) and voiding problems (weak stream, hesitancy).
- Worsening Symptoms: A Japanese study and a review of the FDA Adverse Event Reporting System found that the initiation of statins was associated with an increase in LUTS diagnoses, particularly storage symptoms, often within the first few months [1.2.2, 1.2.3]. This effect may be more prominent in women shortly after starting the medication [1.3.2].
- Improving Symptoms: In contrast, other studies have found that long-term statin use is associated with a lower prevalence of LUTS, particularly in men over 60 [1.2.4, 1.2.5]. One study noted that statin use was associated with a 6.5- to 7-year delay in the new onset of LUTS in men [1.2.2, 1.2.3].
Bladder Pain Syndrome/Interstitial Cystitis (BPS/IC)
Several studies have investigated a link between statin use and BPS/IC, a chronic condition causing bladder pressure and pain. A population-based study in Taiwan concluded there was an association between statin use and BPS/IC [1.3.5, 1.5.1]. Researchers hypothesized that statins might induce dysfunction in the bladder's protective lining (epithelium) or cause inflammation, contributing to the condition [1.5.1, 1.5.5, 1.5.6].
Urinary Retention
While rare, there is at least one case report of statin-associated underactive bladder leading to urinary retention [1.5.4]. Incomplete bladder emptying is a significant risk factor for developing UTIs, as stagnant urine allows bacteria to multiply.
Statin Side Effect Comparison Table
| Statin (Brand Name) | Reported Urinary/Bladder-Related Side Effects |
|---|---|
| Atorvastatin (Lipitor) | Urinary tract infection is listed as a common side effect [1.7.2, 1.7.3]. Can cause kidney problems in rare cases of severe muscle breakdown [1.7.1]. |
| Rosuvastatin (Crestor) | Urinary tract infection is listed as a side effect [1.8.4]. Associated with an increased risk of hematuria (blood in urine) and proteinuria (protein in urine) compared to atorvastatin [1.8.2, 1.8.3, 1.8.5]. |
| Pravastatin (Pravachol) | Associated with a reduced risk of recurrent UTIs in one study [1.2.1]. Less common side effects can include difficult or painful urination and increased urge to urinate at night [1.9.2, 1.9.3]. |
| Simvastatin (Zocor) | Research has linked it to both potential improvement and worsening of LUTS [1.2.2, 1.2.3]. |
Conclusion: What's the Verdict?
The answer to 'Can statins cause UTI?' is that the link is not definitively causal but is complex and multifaceted.
- A direct connection is plausible, as UTIs are a listed side effect for some of the most common statins like atorvastatin and rosuvastatin [1.7.3, 1.8.4].
- Indirect mechanisms, such as statins contributing to other bladder conditions like LUTS or BPS/IC, could potentially increase an individual's susceptibility to infection [1.3.2, 1.5.1].
- Contradictory evidence suggests that in some populations, particularly those with recurrent UTIs or diabetes, statins like pravastatin might have a protective effect [1.2.1, 1.6.4].
If you are taking a statin and experience symptoms of a UTI—such as painful urination, increased frequency or urgency, and cloudy urine—it is crucial to speak with your healthcare provider. Do not stop taking your medication without medical advice. Your doctor can diagnose the issue, provide appropriate treatment, and help you weigh the significant cardiovascular benefits of your statin therapy against any potential side effects.
For more general information on statins, you can visit: Mayo Clinic
