Medication Management for Overactive Bladder

Introduction

• Presented by Dr. Salil Khandwala at Advanced Urogynecology of Michigan.
• Focuses on different medications for overactive bladder (OAB).

Types of Medications

Anticholinergics

• Examples: Enablex, Sanctuary XR, Oxytrol
• Mechanism: Blocks M3 receptors in the bladder, leading to relaxation.
• M3 vs. M1 and M2 receptors:
  • M1: Salivary glands, brain.
  • M2: Heart.
  • M3: Bladder contraction.
• M3 selectivity is preferred for bladder management.
• Forms: Pills (once a day, some on an empty stomach), patches (applied to dry, non-hairy skin twice a week).
• Advantages of patches: Direct absorption into blood, avoids liver metabolite (N-desethyloxybutynin).
• Side Effects: Dry mouth, constipation. Manage with hydration, biotin, or oral lubricants, and increased fiber intake.
• Concerns: Potential link to dementia, especially in older adults.

Beta Agonists

• Examples: Mirabegron (Myrbetriq), Vibegron (Gemtesa).
• Mechanism: Stimulates beta-3 receptors in the bladder, leading to relaxation.
• Better side effect profile: No dry mouth or constipation, well-tolerated by the elderly.
• Potential concerns: Can worsen uncontrolled high blood pressure.

Side Effects and Management

• Dry Mouth: Occurs due to blockage of salivary gland ducts. Manage with products like Biotene or oral lubricants.
• Constipation: Common; manage with increased fiber, Metamucil, or over-the-counter remedies.
• Dementia Concerns: Some anticholinergics may cross the blood-brain barrier, increasing dementia risk, especially in older adults or those with pre-existing conditions.
  • Trospium and Darifenacin are less likely to cross the blood-brain barrier.
• Metabolism: Importance of liver and kidney function. Some medications are metabolized by specific liver enzymes (CYP2D6, CYP3A4), affected by other drugs like Wellbutrin or Prozac.

Patient-Specific Factors

• Consider the patient’s full medical history, including liver and kidney function, existing conditions like dementia or Parkinson’s, and current medications.
• Cost can be a significant barrier; medication affordability must be considered.
• Realistic expectations and preparation for side effects can improve patient compliance.

Summary

• Effective OAB management requires a thorough understanding of the patient’s medical history and conditions.
• First-line treatments usually involve anticholinergics, with beta agonists as a second option due to better tolerance but less long-term data.
• Patient-specific factors, including cost and potential side effects, dictate the choice of medication.

Next Steps

• Next discussion will focus on realistic expectations and achieving treatment goals.