What medication can be added for a patient with obsessive thoughts about their spouse cheating?

Treatment for Obsessive Thoughts About Spousal Infidelity

For a patient experiencing obsessive thoughts about their spouse cheating, an SSRI at higher-than-depression doses is the recommended first-line pharmacological treatment, with fluoxetine 20-80 mg/day or sertraline 50-200 mg/day being the most evidence-based options. 1

First-Line Medication Options

SSRI Treatment

• SSRIs require higher doses for OCD than for depression:

  • Fluoxetine: Start at 20 mg/day, target range 20-60 mg/day, maximum 80 mg/day 1, 2
  • Sertraline: Start at 50 mg/day, target range 50-200 mg/day, maximum 200 mg/day 1

• Important SSRI considerations:

  • Allow 8-12 weeks at maximum tolerated dose to determine efficacy 1
  • Clinical improvement typically begins by week 6, with maximal improvement by week 12 1
  • Morning administration is recommended for once-daily dosing 2
  • For doses above 20 mg/day, consider once-daily (morning) or BID (morning and noon) scheduling 2

Treatment Algorithm

1. Start with SSRI monotherapy:

   • Begin with fluoxetine 20 mg/day or sertraline 50 mg/day
   • Titrate up every 2-4 weeks as tolerated
   • Target OCD-specific doses (higher than depression doses)
   • Continue for at least 8-12 weeks at maximum tolerated dose before determining efficacy

2. If partial response after adequate trial:

   • Option A: Increase SSRI dose if not at maximum
   • Option B: Add augmentation therapy (see below)

3. If inadequate response to first SSRI:

   • Switch to a different SSRI
   • Consider clomipramine (with caution due to side effect profile) 1, 3

Augmentation Strategies for Partial Response

If the patient shows partial response to SSRI therapy, consider these evidence-based augmentation options:

1. Antipsychotic augmentation:

   • Risperidone or aripiprazole have the strongest evidence 1, 4
   • Particularly effective for treatment-resistant OCD

2. Glutamatergic agents:

   • N-acetylcysteine has the largest evidence base 1
   • Memantine has demonstrated efficacy in several trials 1
   • Other options include lamotrigine, topiramate, riluzole 1, 4

Monitoring and Side Effects

• Monitor for suicidal ideation, especially in the first months and after dose adjustments 1
• Watch for behavioral activation/agitation, which is more common in anxiety disorders 1
• Common side effects of fluoxetine include insomnia, headache, and diminished libido 1
• For persistent insomnia, consider adding mirtazapine, trazodone, or short-term use of lorazepam or zolpidem 1

Common Pitfalls to Avoid

• Inadequate dosing: OCD requires higher SSRI doses than depression 1, 5
• Premature discontinuation: Allow sufficient time (8-12 weeks) at therapeutic doses 1, 6
• Failure to recognize partial response: Consider augmentation strategies rather than switching medications immediately 1
• Insufficient maintenance treatment: Continue treatment for 12-24 months after achieving remission 1

Complementary Approaches

• Cognitive-behavioral therapy with exposure and response prevention (CBT-ERP) has larger effect sizes than pharmacological therapy alone and can be used in combination with medication 1
• Regular physical activity may provide additional benefits 1
• Addressing social isolation through support groups may be beneficial 1

The obsessive thoughts about spousal infidelity may represent a form of OCD, and the treatment approach should follow established OCD pharmacotherapy guidelines with higher SSRI doses than typically used for depression.