A 72-year-old man is brought to the office due to visual disturbances that are causing significant distress. The patient describes seeing prowlers in the bushes outside of his windows at night that disappear when he tries to move in for a closer look. He asked his daughter over to see if she could also see these people, and she could not. The patient says, "I am really worried because I've never experienced anything like this before." He has Parkinson disease, for which he takes carbidopa-levodopa, and generalized anxiety disorder, for which he takes sertraline. Temperature is 36.9 C (98.4 F), blood pressure is 127/77 mm Hg, pulse is 68/min, and respirations are 14/min. The patient is alert and oriented. He has a mild resting tremor but very minimal rigidity. His movements are slightly slowed. Which of the following is the most appropriate next step in management?
This patient's new onset of visual hallucinations is most likely related to Parkinson disease (PD). Psychosis (eg, hallucinations, delusions, paranoia) in PD is common and may be due to the underlying disease process, medication, or a combination of the two. Two of the most common anti-Parkinson medication classes associated with psychosis are dopamine precursors (eg, levodopa) and dopamine agonists (eg, pramipexole).
The first step in management of psychosis in PD includes reviewing the patient's medication and considering a cautious dose reduction (eg, reducing the dose of carbidopa-levodopa in this patient). Patients who do not improve with a reduction or who cannot tolerate a dose reduction due to resurgent motor symptoms can be treated with a low-potency, second-generation antipsychotic (eg, quetiapine, pimavanserin).
(Choice A) Haloperidol is a first-generation antipsychotic with strong dopamine-blocking properties; it would therefore be contraindicated in PD, which is characterized by low dopamine levels due to substantia nigra degeneration.
(Choice B) Pramipexole is a dopamine agonist that is sometimes used for mild PD. However, this agent may produce or exacerbate psychotic symptoms on its own, so adding this medication presents a significant risk of exacerbating the problem.
(Choice C) There is a dose-related risk of psychosis with carbidopa-levodopa, so increasing the dose would be counterproductive.
(Choices D and F) Sertraline is a selective serotonin reuptake inhibitor that does not cause psychosis as an adverse effect and has no antipsychotic efficacy. Decreasing or increasing the dose of sertraline is unlikely to benefit this patient.
Educational objective:
Psychosis may develop in Parkinson disease as a result of the underlying disease process, treatment with anti-Parkinson medications (eg, levodopa, pramipexole), or a combination of the two. In patients treated with anti-Parkinson medications who develop psychotic symptoms, dose reduction should be considered.