17.2 Genitourinary Emergencies: UTI & Pyelonephritis, Renal Colic, Urinary Retention, Priapism & Scrotal Infections
Key Takeaways
The 2025 IDSA guideline defines uncomplicated UTI as bladder-limited infection in women or men, and complicated UTI as infection with fever, systemic signs, flank pain or costovertebral angle tenderness.
For complicated UTI, including pyelonephritis and Gram-negative bacteremia, IDSA 2025 suggests 5 to 7 days of a fluoroquinolone or 7 days of another effective agent once the patient is improving.
Asymptomatic bacteriuria is treated only in pregnancy and before urologic procedures that breach the mucosa, not in older adults with nonspecific confusion or in catheterized patients.
NSAIDs are first-line for renal colic, and an alpha-blocker such as tamsulosin can be offered for distal ureteral stones of 10 mm or less.
Ischemic priapism is treated with aspiration and intracavernosal phenylephrine 100 to 500 mcg/mL in 1 mL doses at least 5 minutes apart for up to 1 hour (AUA/SMSNA 2022).
17.2 Genitourinary Emergencies: UTI & Pyelonephritis, Renal Colic, Urinary Retention, Priapism & Scrotal Infections
Note
Exam scope: the genitourinary part of 2025 outline subtopic 2B3. Obstetric emergencies are covered in Section 13.3, sexually transmitted infections in Section 12.2, and ED culture callbacks in Section 12.3.
Classifying Urinary Tract Infection (IDSA 2025)
The 2025 IDSA guideline on complicated UTI replaced older definitions that labeled every UTI in a man, or in a patient with a urologic abnormality, as "complicated":
| Category | Definition | Examples |
|---|---|---|
| Uncomplicated UTI | Infection confined to the bladder in women or men: dysuria, urgency, frequency, suprapubic pain, with no fever or systemic signs | Acute cystitis |
| Complicated UTI | Infection beyond the bladder: fever, chills or rigors, hemodynamic instability, flank pain or costovertebral angle tenderness | Pyelonephritis, febrile catheter-associated UTI, urosepsis, many prostatic infections |
Asymptomatic Bacteriuria (IDSA 2019)
Bacteria in the urine without urinary symptoms is common, especially in older adults and catheterized patients. Screen and treat only:
- In pregnancy
- Before urologic procedures that breach the mucosa
Do not treat asymptomatic bacteriuria in older adults with falls or delirium but no fever or systemic signs, in people with diabetes, or in patients with long-term catheters. Pyuria alone is not a reason to treat. Unnecessary antibiotics cause C. difficile infection, resistance and adverse effects. Look for other causes of the confusion.
Acute Uncomplicated Cystitis
| Agent | Regimen | Notes |
|---|---|---|
| Nitrofurantoin monohydrate/macrocrystals | 100 mg twice daily for 5 days | Bladder levels only, so not for pyelonephritis; avoid when CrCl is below 30 mL/min (2023 AGS Beers Criteria) |
| Trimethoprim-sulfamethoxazole | 160/800 mg twice daily for 3 days | Use only if local resistance is below about 20% and the patient has not used it in the past 3 months; watch potassium and warfarin interactions |
| Fosfomycin | 3 g single dose | Convenient, but slightly less effective |
| Pivmecillinam (FDA-approved 2024) | 185 mg three times daily for 3 to 7 days | Penicillin-class agent for women |
| Gepotidacin (FDA-approved 2025) | 1,500 mg twice daily for 5 days | First-in-class triazaacenaphthylene for women and girls 12 years and older weighing at least 40 kg; review interactions and QT risk |
| Oral beta-lactams | Amoxicillin-clavulanate, cefpodoxime, cephalexin | Less effective than first-line agents |
| Fluoroquinolones | Ciprofloxacin, levofloxacin | Reserved for patients with no alternatives because of boxed warnings for tendon, nerve and CNS harm (Section 12.3) |
Sulopenem etzadroxil with probenecid (2024) is another oral option for women with limited alternatives.
Complicated UTI and Pyelonephritis (IDSA 2025)
Empiric Therapy
IDSA recommends a four-step approach:
- Assess severity: sepsis or septic shock calls for broader initial coverage.
- Review prior urine cultures from the past 3 to 6 months, and avoid drugs to which an earlier isolate was resistant.
- Consider patient risks, such as recent antibiotics, healthcare exposure, allergies and kidney function.
- Use the local antibiogram.
A patient in septic shock who has a history of an ESBL-producing organism should start a carbapenem. A stable patient without resistance risks can receive ceftriaxone, or a fluoroquinolone if local resistance allows.
IV-to-Oral Switch and Duration
- Switch to a well-absorbed oral agent active against the isolate once the patient is improving and can take oral medication.
- Duration for patients improving on effective therapy:
- 5 to 7 days of a fluoroquinolone, or
- 7 days of a non-fluoroquinolone agent,
- rather than 10 to 14 days, including patients with Gram-negative bacteremia from a urinary source.
- Days are counted from the first day of effective therapy.
- Longer courses still make sense for slow responders, undrained abscesses, ongoing obstruction or suspected bacterial prostatitis.
Special Situations
- Pregnancy: cystitis and asymptomatic bacteriuria are treated. Pyelonephritis usually means admission for IV ceftriaxone. Avoid fluoroquinolones. ACOG advises using nitrofurantoin and sulfonamides in the first trimester only when no suitable alternative exists, and avoiding sulfonamides near term.
- Infected obstructing stone: this is a urologic emergency that needs urgent decompression (stent or nephrostomy) as well as antibiotics.
- Catheter-associated UTI: replace a catheter that has been in place more than 2 weeks before collecting the culture and starting therapy.
Renal Colic
- NSAIDs are first-line. For ketorolac, 10 mg IV gives about the same pain relief as 15 or 30 mg. Avoid NSAIDs in AKI, advanced CKD, a solitary kidney or active bleeding.
- Opioids are add-on therapy for pain that persists. IV acetaminophen and IV lidocaine have been studied, with mixed results for lidocaine.
- Medical expulsive therapy: the AUA suggests offering an alpha-blocker, such as tamsulosin 0.4 mg daily for up to about 4 weeks, for distal ureteral stones of 10 mm or less. Benefit is greatest for stones of 5 to 10 mm; the STONE trial (2018) showed no overall benefit for stones under 9 mm.
- Urgent urology referral: fever with obstruction, AKI, a solitary kidney, or pain or vomiting that cannot be controlled.
Acute Urinary Retention
Medications are a common cause or contributor:
- Anticholinergics: diphenhydramine, hydroxyzine, tricyclic antidepressants, oxybutynin, scopolamine
- Opioids, especially intrathecal or high-dose
- Sympathomimetics: pseudoephedrine, phenylephrine, amphetamines
- Antipsychotics and some muscle relaxants
Decompress the bladder with a catheter. In men with benign prostatic hyperplasia, starting an alpha-blocker (tamsulosin 0.4 mg daily) at least 2 to 3 days before a trial without the catheter improves the chance of voiding. Stop or replace the causative drugs.
Ischemic Priapism
Ischemic (low-flow) priapism is a painful, rigid erection lasting more than 4 hours. It is a compartment syndrome of the penis, and the risk of permanent erectile dysfunction rises with time.
Drug causes:
- Intracavernosal injection therapy (alprostadil, papaverine, phentolamine mixtures)
- Trazodone and antipsychotics with alpha-1 blocking activity (for example chlorpromazine, risperidone, quetiapine)
- Cocaine and other illicit drugs, and PDE5 inhibitors (less commonly)
Sickle cell disease is the most common cause in children.
Treatment (AUA/SMSNA 2022)
- First-line treatment is corporal aspiration, with or without irrigation, plus intracavernosal phenylephrine.
- Phenylephrine: 100 to 500 mcg/mL, given as 1 mL injections at least 5 minutes apart, for up to about 1 hour. Pharmacy should prepare it in advance to avoid calculation errors.
- Monitor blood pressure and heart rate; watch for hypertension and reflex bradycardia, especially in patients with cardiovascular disease.
- In sickle cell disease, give the same urologic first-line treatment; do not delay it while giving hydration, oxygen or exchange transfusion.
Preparation example: phenylephrine 10 mg/mL. For 500 mcg/mL, add 1 mL (10 mg) to 19 mL of normal saline for a 20 mL total. For 100 mcg/mL, add 1 mL to 99 mL of normal saline. Draw doses into labeled 1 mL syringes.
Scrotal Emergencies
Testicular torsion is a surgical emergency; give analgesia, but do not delay urology.
Acute epididymitis (CDC 2021 STI Treatment Guidelines):
| Likely cause | Regimen |
|---|---|
| Chlamydia or gonorrhea (sexually active, typically younger) | Ceftriaxone 500 mg IM once (1 g if 150 kg or more) plus doxycycline 100 mg twice daily for 10 days |
| Sexually transmitted organisms and enteric organisms (insertive anal intercourse) | Ceftriaxone 500 mg IM once plus levofloxacin 500 mg daily for 10 days |
| Enteric organisms only (no STI risk, often after instrumentation or with BPH) | Levofloxacin 500 mg daily for 10 days |
Fournier gangrene is a necrotizing soft tissue infection that needs emergency surgery and broad antibiotics (Section 12.1).
A 28-year-old woman has 2 days of dysuria and frequency with no fever, flank pain or nausea. Her kidney function is normal, she has no drug allergies and she has not taken antibiotics this year. Local E. coli resistance to trimethoprim-sulfamethoxazole is 26%. Which regimen is most appropriate?
Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days
Ciprofloxacin 500 mg twice daily for 7 days
Amoxicillin 500 mg three times daily for 7 days
Nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5 days
A 64-year-old man with fever and flank pain is admitted with pyelonephritis and E. coli bacteremia. The isolate is susceptible to ceftriaxone and ciprofloxacin. By day 3 he is afebrile and eating. Under the 2025 IDSA guideline, what total course is most appropriate if he switches to ciprofloxacin?
14 days, because bacteremia always needs a longer course
21 days, because all UTIs in men involve the prostate
7 days counted from the first day of effective therapy
3 days, because he became afebrile within 72 hours
A 34-year-old man taking trazodone has had a painful, rigid erection for 6 hours. Urology will aspirate and inject intracavernosal phenylephrine. Pharmacy has phenylephrine 10 mg/mL vials. Which preparation and dosing plan follows the AUA/SMSNA guideline?
Oral pseudoephedrine 60 mg, repeated in 1 hour if needed
Phenylephrine 100 mcg/min as a peripheral IV infusion
1 mL of the undiluted 10 mg/mL vial, injected every 2 minutes
1 mL of 10 mg/mL added to 19 mL saline; 1 mL doses at least 5 minutes apart
An 86-year-old nursing home resident is sent in for increased confusion over 2 days. Temperature is 37.0 °C, vital signs are normal, and she has no urinary symptoms or flank tenderness. A urinalysis shows pyuria, and the culture grows more than 100,000 CFU/mL of E. coli. What is the best antimicrobial decision?
Start nitrofurantoin for 5 days because pyuria confirms infection
Give ceftriaxone 1 g IV daily for 7 days as complicated UTI
Do not treat the bacteriuria, and look for other causes of the confusion
Give a single dose of fosfomycin 3 g to clear the bacteriuria
Sections you finish are checked off in the contents.