Long-acting injectable antipsychotics — consultant viva

Station structure

Time: 8–10 minutes. Depth: consultant teaching registrar. Expect agent-specific initiation rules, named trials, and ethical framing of injectables without inventing exact local milligram tables as universal law.[3][4]

Core questions and model points

1. What is an LAI and when do you offer it? Extended-release parenteral antipsychotic for maintenance; offer for preference or adherence risk, including early-phase — shared decision, not punishment. Cite PRELAPSE and Tiihonen early depot advantage.[1][4]

2. Key evidence ladder? Tiihonen FEP depot HR ~0.36 vs oral same compound; Sweden LAI vs oral rehospitalisation HR ~0.78; Kishimoto multi-design meta benefit; PRELAPSE AOM HR 0.56; Rosenheck negative RLAI RCT as design counterpoint.[1][2][3][4][5]

3. Oral overlap traps? Risperidone microspheres ~3 weeks oral cover; aripiprazole monohydrate often ~14 days oral after first injection; PP1M day 1 + day 8 loads then monthly; PP3M only after stable PP1M.[4][7]

4. Olanzapine LAI special rule? PDSS risk — observe in facility after every injection; efficacy data exist but logistics dominate.[6]

5. When is LAI not enough? True TRRIP TRS after two adequate adherent trials → offer clozapine; LAI may unmask resistance by securing adherence.[8]

6. Monitoring? Same metabolic/EPS/prolactin principles as parent molecule; use injection contacts for structured review; written missed-dose plan.[2][3]

Examiner pushbacks

• "RCTs show no benefit." → Distinguish explanatory RCTs (Rosenheck) from real-world and multi-design meta-analyses; oral adherence is inflated in trials.[3][5]
• "Just start any depot without oral trial." → Multi-week irreversible AE exposure; confirm same-molecule tolerability first.[3]
• "Patient on LAI still psychotic — add another LAI." → Check dose/interval/substances; consider TRS/clozapine pathway.[8]