drug-induced parkinsonism

Etiology

• drugs likely to induce parkinsonism
  • neuroleptics with little or no anticholinergic activity
    • haloperidol (Haldol)
    • fluphenazine (Prolixin)
    • thiothixene
    • chlorpramazine
    • perphenazine
    • loxapine
    • pimozide
    • trifluoperazine
  • atypical antipsychotics
    • aripiprazole (Abilify)
    • olanzapine (Zyprexa)
    • paliperidone (Invega)
    • risperidone (Risperdal)
    • ziprasidone (Geodon, Zeldox)
  • antiemetics
    • prochlorperazine (Compazine)
    • metoclopramide (Reglan)
  • antihypertensives
    • reserpine
    • alpha-methyldopa (rare)
  • tetrabenazine
• less commonly implicated drugs
  • lithium carbonate (rare)
  • clozapine (Clozaril) less commonly
  • quetiapine (Seroquel) less commonly
  • SSRI
    • citalopram (Celexa)
    • fluoxetine (Prozac)
    • praxoetine (Paxil)
    • sertraline (Zoloft)
  • valproate (Depakene, Depakote)
  • amiodarone
  • flunarizine

Epidemiology

• more common in women
• more common in the elderly

Clinical manifestations

• signs generally develop within 3 months of starting offending agent
• may persist for several months after discontinuing offending agent
• tremor less common than Parkinson's disease
• bradykinesia is generally symmetric
• absence of typical nonmotor features of Parkinson's disease
• may not be distinguishable from Parkinson's disease

Management

• discontinue offending agent if possible
  • symptoms may persist for up to 6 months
• substituting antipsychotic for one with more anticholinergic activity
• substitute antipsychotic with lamotrigine
• trihexyphenidyl (Artane)
• amantadine, start 100 mg BID
• L-dopa is of no value if the offending neuroleptic is continued & may worsen underlying psychotic disorder

More general terms

• parkinsonism
• drug-induced movement disorder

Additional terms

• anti-emetic
• antipsychotic agent
• bradykinesia
• fluphenazine (Prolixin, Anatensol, Triflumethazine, Calmansial, Modecate)
• haloperidol (Haldol, Halperon, Aloperidol, Halomonth)
• levodopa; L-3-hydroxytyrosine; L-3,4-dihydroxyphenylalanine; L-dopa (Dopar, Larodopa, Inbrija)
• lithium carbonate (Eskalith, Lithane, Lithobid, Lithonate)
• methyldopa (Aldomet)
• metoclopramide (Reglan, Metozolv ODT)
• neuroleptic
• Parkinson's disease (paralysis agitans, PD)
• prochlorperazine (Compazine, Stemetil, Novamin, Buccastem)
• reserpine (Serpasil, Apoplon)
• thiothixene (Navane, Tiotixene)
• trihexyphenidyl (Artane, Trihexy)