What to do next for a patient with impaired renal function, experiencing intermittent chronic muscle spasms, on two second-generation antipsychotics (SGAs) who fears discontinuation due to risk of hallucinations, paranoia, and psychosis recurrence?

Management of Chronic Muscle Spasms in a Patient with Impaired Renal Function on Two SGAs

For a patient with impaired renal function (GFR 60, creatinine 1.21) experiencing chronic muscle spasms while on two second-generation antipsychotics (SGAs), the most appropriate approach is to consider switching to a single SGA with better renal safety profile rather than discontinuing antipsychotic treatment entirely, as this would maintain psychiatric stability while reducing medication burden on the kidneys.

Assessment of Current Situation

• Current status: Patient has:

  • Impaired renal function (GFR 60, creatinine 1.21)
  • Chronic intermittent muscle spasms for years
  • On two SGAs
  • History of hallucinations, paranoia, and psychosis
  • Normal CK 261 and LFTs

• Risk factors to consider:

  • Renal impairment increases risk of medication side effects
  • Multiple antipsychotics increase risk of adverse effects
  • Chronic muscle spasms may be medication-related

Management Strategy

Step 1: Medication Review and Optimization

1. Consolidate to single SGA therapy:

   • Antipsychotic polypharmacy should be avoided when possible 1
   • Consider transitioning to a single SGA with:
     • Better renal safety profile
     • Lower risk of extrapyramidal symptoms
     • Adequate efficacy for psychosis control

2. Preferred SGA options for renal impairment:

   • Aripiprazole is often preferred in renal impairment due to minimal renal clearance 2
   • Brexpiprazole may also be considered as it has similar properties 3
   • Avoid clozapine and olanzapine in patients with metabolic concerns 4

3. Transition approach:

   • Cross-titration rather than abrupt discontinuation
   • Gradually taper one SGA while maintaining or increasing the other
   • Monitor closely for withdrawal symptoms or psychosis recurrence 5

Step 2: Address Muscle Spasms

1. Evaluate cause of muscle spasms:

   • Rule out tardive dyskinesia:
     • Assess for involuntary movements in orofacial region or other body parts 1
     • If present, consider switching to an SGA with lower risk of movement disorders

2. If spasms are medication-related:

   • Consider dose reduction of current SGA if clinically feasible 1
   • Monitor for akathisia which can be misinterpreted as restlessness 1

3. If spasms are not medication-related:

   • Consider non-pharmacological approaches first
   • If pharmacological treatment is necessary, avoid nephrotoxic agents

Step 3: Renal Function Monitoring

1. Regular monitoring:

   • Monitor serum creatinine every 3-4 weeks initially, then quarterly 1
   • Watch for signs of worsening renal function
   • Consider nephrology consultation if renal function deteriorates

2. Warning signs requiring immediate action:

   • Increase in serum creatinine by 0.5 mg/dL or more
   • Serum creatinine exceeding 1.4 mg/dL 1
   • New onset or worsening edema

Step 4: Patient Education and Follow-up

1. Psychoeducation:

   • Explain the importance of medication adherence to prevent psychosis relapse 5
   • Discuss warning signs requiring immediate attention
   • Emphasize the connection between kidney health and medication management

2. Follow-up schedule:

   • Weekly visits during medication changes 5
   • Monthly visits once stable to monitor symptoms, side effects, and compliance

Special Considerations

• Avoid medications that may worsen renal function:

  • NSAIDs should be avoided in patients with renal impairment 1
  • Lithium should be used with extreme caution if at all 6

• Caution with benzodiazepines:

  • If used for muscle spasms, taper slowly to avoid withdrawal symptoms 1
  • Monitor for increased sedation due to decreased renal clearance

• Risk of psychosis with abrupt medication changes:

  • Abrupt cessation of medications can lead to withdrawal symptoms including psychosis 7
  • This risk is heightened in patients with renal impairment 8

Conclusion

The management of this patient requires balancing psychiatric stability with renal protection. Consolidating to a single SGA with a favorable renal profile is the most prudent approach, along with careful monitoring of both psychiatric symptoms and renal function. Aripiprazole or brexpiprazole would be reasonable choices for monotherapy given the patient's renal impairment and chronic muscle spasms.