Is it appropriate to order Buspar (buspirone) or Gabapentin for a patient with a history of psychotic episodes, currently on Risperidone (risperidone), and experiencing anxiety and cravings for THC and nicotine?

Buspirone and Gabapentin for Anxiety in Psychotic Disorder on Risperidone

Primary Recommendation: Avoid Buspirone, Consider Gabapentin with Caution

Buspirone is contraindicated in this patient due to documented risk of worsening psychosis, particularly in patients with established psychotic disorders. 1, 2 Gabapentin may be considered as a safer alternative for anxiety management, though evidence is limited in this specific population.

Evidence Against Buspirone in Psychotic Disorders

Direct Contraindication

• The FDA label explicitly warns that buspirone has no established antipsychotic activity and should not be employed in lieu of appropriate antipsychotic treatment 1
• Case reports demonstrate buspirone-induced worsening of psychosis in patients with schizoaffective disorder, manifesting as increased aggression, odd behaviors, paranoia, and substantially decreased oral intake 2
• Buspirone acts as an antagonist at presynaptic dopamine D2, D3, and D4 receptors, yet paradoxically results in substantial increases in dopaminergic metabolites rather than producing antipsychotic effects 2

Mechanism of Psychosis Exacerbation

• Despite its complex serotonergic mechanism through 5-HT1A receptors, buspirone's dopaminergic effects can destabilize patients with psychotic disorders 2, 3
• The drug's inability to produce antipsychotic effects while increasing dopaminergic activity creates a particularly hazardous profile for patients with schizophrenia spectrum disorders 2

Additional Safety Concerns

• The FDA warns of potential serotonin syndrome when buspirone is combined with antipsychotics or other dopamine antagonists like risperidone 1
• Serotonin syndrome symptoms include mental status changes (agitation, hallucinations, delirium), autonomic instability, neuromuscular changes, and seizures 1
• Treatment with buspirone and any concomitant antidopaminergic agents should be discontinued immediately if serotonin syndrome occurs 1

Gabapentin as Alternative for Anxiety

Limited but Supportive Evidence

• Anticonvulsants used as mood stabilizers, particularly pregabalin or gabapentin, may provide anxiolytic effects in patients with bipolar disorder and comorbid anxiety 4
• Gabapentin lacks the dopaminergic interactions that make buspirone problematic in psychotic disorders 4

Dosing Considerations

• Start gabapentin at 100-300 mg at bedtime to assess tolerability 4
• Titrate gradually by 100-300 mg every 3-7 days to a target of 900-1800 mg daily in divided doses 4
• Monitor for sedation, dizziness, and potential interaction with risperidone 4

Optimal Management Strategy for This Patient

First-Line Approach: Optimize Current Antipsychotic

• Ensure risperidone is at therapeutic dose (2-4 mg/day for psychosis) before adding anxiolytics 5, 6
• Anxiety symptoms often improve with adequate antipsychotic dosing in patients with psychotic disorders 5

Non-Pharmacological Interventions

• Cognitive-behavioral therapy should be the primary intervention for comorbid anxiety symptoms 4
• Psychoeducation about symptoms, course of illness, and treatment options improves outcomes 5, 4

PRN Benzodiazepines for Acute Anxiety

• Low-dose lorazepam (0.25-0.5 mg PRN) provides rapid anxiolytic effects without worsening psychosis 4, 7
• Prescribe with clear instructions: maximum 2 mg lorazepam equivalent daily, not more than 2-3 times weekly 4
• Benzodiazepines should be time-limited (days to weeks) to avoid tolerance and dependence 4

Addressing Substance Cravings

THC and Nicotine Management

• The NCCN recommends bupropion or varenicline for nicotine cessation, though bupropion carries seizure risk and should be avoided in patients with brain pathology 5
• Varenicline shows superior abstinence rates compared to placebo (OR 2.07) and may be preferable for nicotine cessation 5
• Combination NRT (nicotine patch plus short-acting form) provides effective craving management without psychosis risk 5

Psychosocial Interventions for Substance Use

• Cognitive-behavioral therapy specifically targeting substance use patterns and triggers should be implemented once acute mood symptoms stabilize 4
• Family-focused therapy helps with early warning sign identification and reducing access to substances 4

Critical Pitfalls to Avoid

• Never prescribe buspirone to patients with active psychotic disorders or history of psychotic episodes 1, 2
• Avoid combining multiple serotonergic agents (buspirone + risperidone) due to serotonin syndrome risk 1
• Do not use anxiolytics as substitute for adequate antipsychotic dosing 1
• Monitor closely for behavioral activation or worsening psychosis when initiating any new psychotropic medication 2
• Ensure therapeutic drug monitoring if adding gabapentin to verify risperidone levels remain stable 4