Typical (1st generation) antipsychotics

Pimozide 

  • 1mg x 1week then ↑ by 0.5-1mg qweekly until 4-6 mg/day or response, keep stable dose x 1month then taper slowly
  • Most commonly used treatment for delusions of parasitosis

  • Dopamine receptor antagonist

  • Delusional parasitosis (require ~ 5-6 months of treatment then can start tapering)

  • *

  • Sedation 
  • Anticholinergic SE
  • Weight gain
  • ↑ QT interval
  • Withdrawal dyskinesia (transient)
  • Extrapyramidal SE: dystonia, akathisia, Parkinsonism, tardive dyskinesia (long term)

  • ↑ toxicity with CYP3A4 inhibitors: macrolides, protease inhibitors, azole antifungals, grapefruit juice 

  • Can prescribe Benztropine or diphenhydramine to ↓ SE
  • If history of cardiac arrhythmia or conduction abnormality 🡪 ECG pre & post treatment indicated