Can carbamazepine (anticonvulsant/mood stabilizer) cause urinary tract infections (UTIs)?

Carbamazepine and Urinary Tract Infections

Carbamazepine can cause urinary tract infections (UTIs) through several mechanisms, including hypogammaglobulinemia and effects on bladder function that may predispose patients to infection. 1, 2

Mechanisms by which carbamazepine may cause UTIs

Immunological Effects

• Carbamazepine can cause hypogammaglobulinemia (decreased immunoglobulin levels), which compromises immune function and increases susceptibility to infections, including UTIs 2
• A 2021 case-control study found that carbamazepine was significantly associated with an increased risk of UTIs in patients with epilepsy 1
• The immunological and hematological side effects of carbamazepine appear to play an important role in UTI development under anticonvulsant therapy 1

Effects on Bladder Function

• Carbamazepine can cause urological adverse effects including:
  • Increased bladder capacity (up to 1,700 ml in documented cases) 3
  • Overflow urinary incontinence 3
  • Symptoms of urgency and frequency 3
  • Potential antidiuretic effects 4

Risk Assessment and Monitoring

High-Risk Patients

• Patients with recurrent infections should have their immunoglobulin levels checked if they are taking carbamazepine 2
• Elderly or frail patients may be particularly vulnerable to UTI development while on carbamazepine due to:
  • Age-related changes in immune function
  • Potential pre-existing bladder dysfunction
  • Multiple comorbidities 5

Monitoring Recommendations

• Monitor for UTI symptoms in patients taking carbamazepine:
  • Dysuria, frequency, urgency
  • Changes in urine color or odor
  • Suprapubic pain
  • Fever or systemic symptoms in complicated cases 5
• Consider periodic urinalysis in high-risk patients (those with history of recurrent UTIs)
• Be vigilant for atypical presentations of UTI in elderly patients on carbamazepine, which may include:
  • Mental status changes
  • Decreased functional status
  • Weakness or fatigue 5

Management Approach

If UTI Develops

• Obtain urine culture before starting treatment 6
• Choose antibiotics based on local resistance patterns and patient factors:
  • For uncomplicated UTI: Fosfomycin, nitrofurantoin, or pivmecillinam 5
  • For complicated UTI: Consider broader coverage based on culture results 5, 6
• Consider alternative anticonvulsants if recurrent UTIs occur while on carbamazepine:
  • Primidone and phenobarbital have not been convincingly associated with urological side effects 3
  • Discuss risks and benefits of medication changes with patients

Prevention Strategies

• Ensure adequate hydration
• Consider prophylactic measures in high-risk patients with recurrent UTIs
• Monitor immunoglobulin levels in patients with recurrent infections 2

Pitfalls and Caveats

• UTI symptoms may be mistaken for direct urological side effects of carbamazepine (frequency, urgency)
• The relationship between carbamazepine and UTIs may be overlooked, delaying appropriate management
• Discontinuation of carbamazepine should only be considered after careful evaluation of seizure risk versus infection risk
• Drug interactions with carbamazepine are common and may affect the metabolism of antibiotics used to treat UTIs 7

In patients with recurrent UTIs who are taking carbamazepine, consider the medication as a potential contributing factor and evaluate for immunological effects or bladder dysfunction that may predispose to infection.