NUR 7643 Module 1 Parkinson Disease Psychosis Case: Pimavanserin, Low-Dose Clozapine and Antipsychotic Risk Example

Children in the Living Room: Assessing and Treating Psychosis in a 77-Year-Old Man With Parkinson Disease

Student Name

M.S. in Nursing, Psychiatric Mental Health Nurse Practitioner, Thomas Edison State University

NUR-7643: Advanced Assessment, Differential Diagnosis, and Management of Psychiatric Disorders: Geriatric Populations Part B

Mentor Name

Month Day, Year

Children in the Living Room: Assessing and Treating Psychosis in a 77-Year-Old Man With Parkinson Disease

What His Wife Describes

Howard, an invented patient, is 77 and ran a pharmacy in Princeton Junction for forty years. He was diagnosed with Parkinson disease nine years ago and doses carbidopa-levodopa at breakfast, lunch, dinner and bedtime, along with pramipexole, which was added three years ago when his tremor worsened, and amantadine for the writhing movements that came later. Over the past eight months he has begun seeing small children sitting quietly on the sofa in the evenings. Early on he recognized them as tricks of his mind and was more puzzled than afraid. Now he speaks to them and asks his wife to feed them.

For the past two months he has also become convinced that his wife of fifty years is seeing a neighbor. He checks her phone, follows her to the mailbox and last week shouted at the neighbor in the driveway. His wife, frightened and hurt, called his neurologist, who referred him. He sleeps poorly and acts out his dreams, kicking and shouting at night, which his wife says began years before his tremor.

Separating the Causes

Psychosis in an older man with Parkinson disease has several possible sources, and the paper works through each. Delirium is checked first: his attention is intact, his symptoms have built slowly over months rather than days, and his urine, blood count, sodium and kidney function are normal. Dementia is assessed with a cognitive screen that shows mild slowing and trouble with planning, but he still manages his own medicines and finances with help, so he does not meet criteria for dementia, though the paper notes that dementia with Lewy bodies and Parkinson disease dementia often present with visual hallucinations and need to be watched for. Depression is screened and is mild.

His medicines are the most likely trigger. Pramipexole and other dopamine agonists, amantadine and anticholinergic drugs are well known to provoke hallucinations and delusions in Parkinson disease, more so than levodopa itself. The pattern of well-formed silent figures, early insight that was later lost and a jealous delusion fits Parkinson disease psychosis rather than a primary psychotic illness.

The First Step: Simplify the Antiparkinson Drugs

Working with his neurologist, amantadine is tapered and stopped over two weeks, and pramipexole is lowered and then stopped over the following month, with his levodopa raised slightly to hold his movement. His wife records the frequency of the visions and any change in his walking each day. After six weeks, the children appear less often, but the jealous belief remains, and he is still checking her phone and watching the neighbor's house. Further cuts to levodopa would make him stiff and slow and raise his risk of falling, so a medicine for the psychosis is now considered.

The trade-offs are explained to Howard and his wife together. Fewer antiparkinson drugs may mean more stiffness and slower walking, which raises the risk of falls, while the drugs he takes now are feeding the visions and the jealous belief. Howard, who spent his career explaining medicine side effects to customers, follows the reasoning and agrees to the changes in steps.

Choosing an Antipsychotic

Weintraub et al. (2016) compared 7,877 veterans with Parkinson disease who started an antipsychotic with 7,877 matched veterans who did not. Antipsychotic use was linked with more than twice the risk of death, a hazard ratio of 2.35, and older typical drugs carried even higher risk than the newer ones. Among the atypical drugs, the risk was highest with olanzapine, then risperidone, then quetiapine. The study was observational and almost all participants were men, which the paper notes, but the size of the effect makes caution essential.

Cummings et al. (2014) tested pimavanserin, a drug that blocks a serotonin receptor rather than dopamine, against placebo in 199 adults with Parkinson disease psychosis for six weeks after a two-week lead-in of nondrug support. Psychosis scores fell by 5.79 points with pimavanserin compared with 2.73 with placebo, a moderate effect, and motor function did not worsen. Ten patients on pimavanserin stopped because of side effects, compared with two on placebo.

An earlier six-site trial (Parkinson Study Group, 1999) had tested low-dose clozapine, at an average of about 25 mg a day, against placebo in 60 patients with drug-induced psychosis in Parkinson disease for four weeks. Psychosis improved substantially on all three measures used, and tremor even improved slightly, while motor function did not worsen. Because clozapine can lower white blood cell counts dangerously, blood counts were checked weekly.

Pimavanserin is chosen because it does not block dopamine and was tested in a large trial. Howard and his wife are told about the boxed warning on all antipsychotics in older adults with dementia-related psychosis, that he does not have dementia now but is at risk, and that the decision will be reviewed every three months. An electrocardiogram is done first because pimavanserin can lengthen the QT interval. If it fails or is not covered by his insurance, low-dose clozapine with weekly blood counts for the first months is the next option.

Protecting the Marriage and the Home

The jealous delusion is hard on his wife. She is given time alone to talk about it and told that it is a symptom of his illness and not a reflection of their marriage. She is advised not to argue with the belief but to reassure him calmly and change the subject. The neighbor is told, with Howard's consent, that he has a medical condition. A Parkinson support group for spouses meets monthly at their hospital. His dream enactment, likely a sleep behavior disorder common in Parkinson disease, is referred to a sleep clinic, and the bedroom is made safer by moving the nightstand and padding the floor.

Conclusion

Howard has Parkinson disease psychosis, with visual hallucinations and a jealous delusion, after delirium was excluded and dementia was checked. Stopping amantadine and pramipexole reduced the visions but not the delusion. Pimavanserin, supported by a trial that showed benefit without worse movement, is started with an electrocardiogram and a frank discussion of antipsychotic risk drawn from a large mortality study, with low-dose clozapine in reserve. His wife's support, the neighbor, his sleep and safety at night are part of the plan, and a cognitive screen will be repeated in six months.

References

Cummings, J., Isaacson, S., Mills, R., Williams, H., Chi-Burris, K., Corbett, A., Dhall, R., & Ballard, C. (2014). Pimavanserin for patients with Parkinson's disease psychosis: A randomised, placebo-controlled phase 3 trial. The Lancet, 383(9916), 533-540. https://doi.org/10.1016/S0140-6736(13)62106-6

Parkinson Study Group. (1999). Low-dose clozapine for the treatment of drug-induced psychosis in Parkinson's disease. New England Journal of Medicine, 340(10), 757-763. https://doi.org/10.1056/NEJM199903113401003

Weintraub, D., Chiang, C., Kim, H. M., Wilkinson, J., Marras, C., Stanislawski, B., Mamikonyan, E., & Kales, H. C. (2016). Association of antipsychotic use with mortality risk in patients with Parkinson disease. JAMA Neurology, 73(5), 535-541. https://doi.org/10.1001/jamaneurol.2016.0031