Tse W, Frisina PG, Haelbit TD, et al. The Effects of Withdrawal of Dopaminergic Medication in Nursing Home Patients With Advanced Parkinsonism. Journal of the American Medical Directors Association 2008;9:670-75
PubMed link: https://www.ncbi.nlm.nih.gov/pubmed/18992700
| Methods | Study design: Randomized double-blind, placebo-controlled study with a parallel-design
Number of groups: Two groups |
| Participants | Number of participants: 11 randomized, 10 completed
· Active deprescribing group: 6 randomized, 5 completed · Control group: 5 randomized, 5 completed Age: 82.0 ± 10.1 years Sex: 7 females, 4 males Participants with dementia: Yes, all – MMSE below 19 was an inclusion criteria Inclusion criteria: · Parkinsonism (defined as requiring the presence of bradykinesia and at least one of the following: rest tremor, rigidity, or postural instability) · Dementia, defined as MMSE below 19 · Already being treated with levodopa · Not on any other anti-PD medications for at least 30 days before inclusion into the study. Exclusion criteria: · Current or past treatment with antipsychotic medications · History of central nervous system structural lesions such as cerebral mass lesions · Stroke Country: United States of America Setting: Residential aged care facility |
| Interventions | Medicine: Levodopa
Withdrawal Schedule: Not described Comparator: Placebo compared to continued treatment |
| Outcomes | MMSE
Unified Parkinson’s Disease Rating Scale Nursing assistant behavioral detection form Hoehn and Yahr staging scale Motor and behavioral deterioration as assessed by the blinded floor physician |
| Dates | Dates: Not described
Follow-up duration: 32 days |
| Funding sources | The Leir Foundations, the Dextra Baldwin McGonagle Foundations and the Joseph E. and Norma G. Saul Foundation. |
| Notes |
Risk of bias table
| Bias | Authors’ judgment | Support for judgment |
| Random sequence generation (selection bias) | Unclear risk | Not described:
“Subjects were randomized into two groups: one group would undergo levodopa withdrawal (experimental group) and the second group (control group) would continue on their levodopa medication regimen.” |
| Allocation concealment (selection bias) | Unclear risk | Not described |
| Blinding of participants and personnel (performance bias) | Unclear risk | Method of blinding not described. However, blinding claimed, so probable that this was done.
The study is described as randomized and double-blind. No method of blinding participants (e.g. placebo) is mentioned. Literal reading of the text indicates the number of tablets was progressively reduced. I think the participants would know whether the tablets were reduced or not. |
| Blinding of outcome assessment (detection bias) | Unclear risk | Personnel and assessors were blinded as shown in the text belowthough blinding method not described:
“The motor part of the Unified Parkinson’s Disease Rating (UPDRS-III) was assessed by neurologists (W.T. and W.K.) who were blinded to the subjects’ medication status.” |
| Incomplete outcome data (attrition bias) | Unclear risk | It appears that there were no missing data except for one patient who developed a fever. Since this one patient represents 10% of the study population and the fever could have been caused by the intervention, it makes the risk of bias unclear.
Because one patient in the experimental group developed an adverse event after T3, this patient’s assessments were censored from the data at T4. |
| Selective reporting (reporting bias) | High risk | The Hoehn and Yahr staging scale outcomes were not reported in the study.
Unified Parkinson’s Disease Rating – yes |
| Other bias | High risk | “The other subcomponents of the Unified Parkinson’s Disease Rating were not assessed, as these all involve assessment of symptomatology by history, which could not be reliably obtained in this severely cognitively impaired population.”
No mention of doses of levodopa was made. The rate of tapering was constant (100mg every 3 days) but the starting point may have been variable. It is possible that tapering at this speed could produce neuroleptic malignant syndrome, which would manifest as a fever and stiffness. These are the very symptoms that the patients showed after withdrawal. |
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