Tamsulosin and passage of renal stones

No significant benefit in a randomized trial.

Asymptomatic (incidentally discovered) microscopic hematuria: what’s the most cost effective way to work it up?

The combination of ultrasound and cystoscopy is the winner.

Tamsulosin effective in facilitating passage of stones up to 10 mm in size

An evidence summary form American Family Physician.

Desmopressin spray approved for nocturnal polyuria

From JAMA.

Citrate salts for treating and preventing kidney stones

Beneficial in this evidence summary.

Pioglitazone and bladder cancer

This BMJ study adds strength to the association:

Design Population based cohort study.

Setting General practices contributing data to the United Kingdom Clinical Practice Research Datalink.

Participants A cohort of 145 806 patients newly treated with antidiabetic drugs between 1 January 2000 and 31 July 2013, with follow-up until 31 July 2014.

Main outcome measures The use of pioglitazone was treated as a time varying variable, with use lagged by one year for latency purposes. Cox proportional hazards models were used to estimate adjusted hazard ratios with 95% confidence intervals of incident bladder cancer associated with pioglitazone overall and by both cumulative duration of use and cumulative dose. Similar analyses were conducted for rosiglitazone, a thiazolidinedione not previously associated with an increased risk of bladder cancer.

Results The cohort generated 689 616 person years of follow-up, during which 622 patients were newly diagnosed as having bladder cancer (crude incidence 90.2 per 100 000 person years). Compared with other antidiabetic drugs, pioglitazone was associated with an increased risk of bladder cancer (121.0 v 88.9 per 100 000 person years; hazard ratio 1.63, 95% confidence interval 1.22 to 2.19). Conversely, rosiglitazone was not associated with an increased risk of bladder cancer (86.2 v 88.9 per 100 000 person years; 1.10, 0.83 to 1.47). Duration-response and dose-response relations were observed for pioglitazone but not for rosiglitazone.

Conclusion The results of this large population based study indicate that pioglitazone is associated with an increased risk of bladder cancer. The absence of an association with rosiglitazone suggests that the increased risk is drug specific and not a class effect.

This is unfortunate because pioglitazone was one of only two diabetes drugs (the other being metformin) associated with better macrovascular outcomes.

How to work up hematuria

This topic was recently reviewed in Advances in Chronic Kidney Disease. From the body of the paper:

On finding a urine dipstick positive for blood, the test should be repeated after several days, to account for any transient causes of MH, such as physical activity, sexual intercourse, or menstruation. If the dipstick remains positive, urine microscopy should be performed to identify RBCs and to define their morphology (dysmorphic or isomorphic)..For our purposes, we define MH as 3 or more RBC/hpf. If no RBCs are visualized, patients should be evaluated for alternative causes of a positive dipstick, such as myoglobinuria. We agree with the CUA guidelines ² and Huussen and colleagues, ³⁵ who suggest that urologic imaging and cystoscopy may not be required if dysmorphic cells or RBC casts are seen, suggesting a glomerular etiology. Such findings should, however, prompt assessment of kidney function and urinary protein excretion. If the patient has a reduced GFR or proteinuria, referral to nephrology is warranted and a kidney biopsy should be considered. For those individuals with isolated glomerular MH, a clinician should assess these patients annually for kidney function changes and/or the development of albuminuria or proteinuria. If isomorphic RBCs are seen on urine microscopy, the clinician should confirm with the patient whether possible benign causes of MH such as recent physical activity or trauma, sexual activity, menstrual bleeding, viral symptoms, or urethral instrumentation may account for these findings. If a benign cause is present, a repeat urinalysis should be done in several weeks to ensure resolution. If the earlier mentioned causes are not identified, imaging of the GU tract is indicated. Although CTU has demonstrated the best testing characteristics, we emphasize the importance of limiting cumulative doses of radiation exposure, especially in younger individuals..alternative imaging modalities should be considered, including US or MR...

If no parenchymal lesion is detected on imaging, the clinician should assess the patient's GU cancer risk factor profile. If risk factors are present, they should be promptly referred to urology for cystoscopy. If a patient has no such risk factors, age should be considered before undergoing cystoscopic evaluation. We consider the evidence presented in the 2012 AUA guidelines inadequate to support cystoscopy for anyone with asymptomatic MH younger than 40 years. Patients with asymptomatic MH aged 50 years or older have sufficient cancer risk to warrant cystoscopy, regardless of risk factor profile. 6 For patients aged 40 to 49 years, the data are unclear; if no risk factors are present, clinical judgment for cystoscopy referral is advised.

Prevention of recurrent kidney stones

New guidelines are out from the ACP available as free full text here.

From the guideline document:

Recommendation 1: ACP recommends management with increased fluid intake spread throughout the day to achieve at least 2 L of urine per day to prevent recurrent nephrolithiasis. (Grade: weak recommendation, low-quality evidence)

Recommendation 2: ACP recommends pharmacologic monotherapy with a thiazide diuretic, citrate, or allopurinol to prevent recurrent nephrolithiasis in patients with active disease in which increased fluid intake fails to reduce the formation of stones. (Grade: weak recommendation, moderate-quality evidence)

The evidence for dietary interventions was mixed and not strong enough for the authors to include a recommendation. Also, the guideline states that the evidence was insufficient to support pre-treatment or on-treatment stone analysis or determination of urine composition.

Cranberry to prevent UTI

After all these years there's little to support it. The evidence is mixed at best. There is a nice rundown at Clinical Correlations.

Uric acid as a risk factor for erectile dysfunction

In this study there was a two fold increase in risk of ED for every 1 mg/dL increase in uric acid.

HT to Clinical Cases and Images.

How to prevent recurrent kidney stones: American College of Physicians guidelines for adults

Available as free full text from the Annals of Internal Medicine.

Inhaled anticholinergics and acute urinary retention in COPD

Inhaled anticholinergics increased the risk of urinary retention in this study.

VRE urinary tract infections: when and how to treat

Review in Pharmacotherapy. Full text via Medscape.

Urologic emergencies in men

Priapism, testicular torsion, paraphimosis and Fournier's gangrene are reviewed.

What to do about asymptomatic funguria

In many cases it represents colonization and responds to simple measures such as removal of foley catheters, but there are exceptions. Here is a discussion in The Hospitalist.