(FDA approved in bold)

• Parkinson’s disease (PD)
  
• Drug-induced extrapyramidal reactions
  
• Influenza-A prophylaxis/treatment
  
• Post-encephalitic Parkinsonism
  
• Vascular Parkinsonism
  
• Fatigue in multiple sclerosis (MS)
  
• Enhancing arousal after traumatic brain injury
  
• Attention deficit hyperactivity disorder
  
• SSRI-related sexual dysfunction

• The mechanism of action in PD is poorly understood but animal studies suggest either that it induces release or decreases reuptake of dopamine. Also is a weak N-methyl-D-aspartic acid (NMDA) receptor antagonist which in animals decreases release of acetylcholine from the striatum. Treats and prevents influenza-A by preventing the release of viral nucleic acid into the host cell due to interfering with the function of a viral M2 protein. It may also prevent virus assembly during replication

• PD – 48 hours or less

• PD – most patients require dose adjustment over time and most PD patients will need to take other agents, such as levodopa

• PD – Motor symptoms, such as bradykinesia, gait, and tremor should improve. Reduces extrapyramidal reactions, such as dyskinesias, and can allow reduction of carbidopa-levodopa doses. Non-motor symptoms, including autonomic symptoms such as postural hypotension, depression, and bladder dysfunction, do not improve. If the patient has significantly impaired functioning, add levodopa or a dopamine agonist
  
• Fatigue – MS-related fatigue may respond to pemoline or modafinil

• For suboptimal effectiveness add carbidopa-levodopa with or without a COMT inhibitor or dopamine agonist depending on disease severity. Monoamine oxidase (MAO)-B inhibitors may also be beneficial
  
• For younger pat0ients with bothersome tremor: anticholinergics may help
  
• For severe motor fluctuations and/or dyskinesias with good “on” time, functional neurosurgery is an option
  
• Depression is common in PD and may respond to low dose selective serotonin reuptake inhibitors
  
• Cognitive impairment/dementia is common in mid-late stage PD and may improve with acetylcholinesterase inhibitors
  
• For patients with late-stage PD experiencing hallucinations or delusions, withdraw amantadine and consider oral atypical neuroleptics (quetiapine, olanzapine, clozapine). Acute psychosis is a medical emergency that may require hospitalization

• None required