What is the recommended treatment regimen and management plan for genitourinary tuberculosis?

Treatment of Genitourinary Tuberculosis (GUTB)

Genitourinary tuberculosis should be treated with the same six-month regimen used for respiratory tuberculosis: rifampicin and isoniazid for six months, supplemented by pyrazinamide and ethambutol for the first two months. 1

Standard Treatment Regimen

Initial Intensive Phase (2 months)

• Administer four drugs daily: 1

  • Rifampicin: 450 mg if <50 kg or 600 mg if ≥50 kg 1
  • Isoniazid: 300 mg daily (5 mg/kg) 1
  • Pyrazinamide: 1.5 g if <50 kg or 2.0 g if ≥50 kg (35 mg/kg) 1
  • Ethambutol: 15 mg/kg daily 1

• The fourth drug (ethambutol) can be omitted only in previously untreated patients with low risk of isoniazid resistance (HIV-negative, not contacts of drug-resistant cases). 1

Continuation Phase (4 months)

• Continue rifampicin and isoniazid only for an additional four months at the same doses. 1
• This yields a total treatment duration of 6 months. 1, 2

Evidence Supporting Six-Month Regimen

The British Thoracic Society explicitly states that genitourinary tuberculosis should receive "the six month regimen used in respiratory tuberculosis." 1 This recommendation is supported by a prospective study of 106 patients with bacteriologically proven urogenital TB, which demonstrated that six-month chemotherapy (2 months RMP/INH/PZA followed by 4 months RMP/INH) resulted in only one relapse during 45-63 months of follow-up, proving it as efficient as the previous 18-24 month standard. 2

Alternative Dosing Schedules

While daily therapy is preferred, intermittent dosing can be used when directly observed therapy (DOT) is implemented: 1

• Twice weekly after initial 2 weeks: Rifampicin 600-900 mg, isoniazid 15 mg/kg, pyrazinamide 2.5-3.5 g (depending on weight) 1
• Three times weekly throughout: All drugs given three times weekly from the start 1

When to Extend Treatment Beyond Six Months

Consider longer treatment duration in specific circumstances: 3

• Cavitary kidney disease 3
• Kidney abscess or significant renal dysfunction 3
• HIV co-infection 3, 4
• Complicated urinary tuberculosis requiring surgery 5

However, the core guideline evidence does not mandate extension beyond six months for uncomplicated GUTB. 1

Critical Management Considerations

Close Monitoring During Treatment

Patients with GUTB require close supervision starting immediately at treatment initiation because rapid progression of scarring and tissue destruction can occur even after starting appropriate therapy. 6 One case report documented severe progressive scarring, ureteral obstruction, contracted bladder, and urethral stricture developing soon after initiating medical therapy, ultimately requiring nephrectomy and reconstructive surgery. 6

Surgical Intervention

Surgery may be indicated for complicated urinary tuberculosis, including: 5, 3

• Urinary tract obstruction (treat with corticosteroids or surgery) 3
• Progressive tissue destruction despite appropriate chemotherapy 6
• Preservation of renal function when medical therapy fails 6

Monitoring Requirements

• Baseline and regular liver function tests are required, particularly in the first two months of treatment. 1
• Visual acuity monitoring if using ethambutol, especially at 15 mg/kg dosing. 1
• Clinical assessment for treatment response and complications throughout the six-month course. 5

Special Populations

Pregnancy

• All first-line drugs (rifampicin, isoniazid, pyrazinamide, ethambutol) can be used during pregnancy. 1, 4
• Avoid streptomycin due to fetal ototoxicity. 1, 4
• Add prophylactic pyridoxine 10 mg/day. 1, 4

Diabetes Mellitus

• Use the same regimen as non-diabetic patients. 1, 4
• Strict glucose control is mandatory and oral hypoglycemic doses may need to be increased due to rifampicin interaction. 1, 4
• Add prophylactic pyridoxine. 4

Renal Impairment

• Rifampicin, isoniazid, and pyrazinamide can be given in standard doses. 1
• Reduce ethambutol and streptomycin doses and monitor serum concentrations. 1

HIV Co-infection

• Use standard six-month chemotherapy but anticipate higher relapse rates. 4
• Rifampicin induces metabolism of protease inhibitors and NNRTIs, requiring careful coordination of antiretroviral therapy. 4
• Consider efavirenz-based ART which can be used without dose adjustment. 4

Drug-Resistant GUTB

For multidrug-resistant tuberculosis (MDR-TB), treatment requires: 5, 3

• Long-term intravenous aminoglycosides and other second-line drugs with considerable toxicity 3
• Treatment duration of 18-24 months 3
• Referral to specialized units with experience in MDR-TB management 4

Common Pitfalls to Avoid

• Do not use shorter regimens than six months for uncomplicated GUTB—this is the evidence-based minimum. 1, 2
• Do not assume GUTB requires longer treatment than pulmonary TB unless CNS involvement or specific complications are present. 1
• Do not delay close monitoring—tissue destruction can progress rapidly even with appropriate therapy. 6
• Do not omit pyrazinamide from the initial phase unless contraindicated, as this would necessitate extending treatment to 18 months. 1