Review Article

Patterns and Determinants of Prescribing for Parkinson’s Disease: A Systematic Literature Review

Table 4

Summary of prescribing trends of PD medications and factors associated with their use.

L-dopaDopamine agonists (DAs)COMT inhibitorsMAO-B inhibitorsAmantadineAnticholinergics

General prescribing patternL-dopa was the most commonly prescribed medication in most studies regardless of the year or the design of the study ranged from 37.42% (in Spain) to 100% (in India).
Only one Norwegian study examined the prescribing rate of L-dopa intestinal gel (LCIG).
DAs (non-ergots mainly) were the second most common PD medication prescribed in 16 studies with the prescription rate ranging from 7.63% to 85%.
Studies carried out prior to 2000 showed higher prescription rates of ergot DAs than those carried out after 2000.
There were no data from most studies regarding apomorphine usage.
Large variation in the prescribing rates of COMT inhibitor monotherapy ranged from 1.01% in USA to 29% in USA as well.There were variations in the prescription rates of MAO-B inhibitors ranging from 2.12% in South Africa to 42% in Japan.There was wide variation, ranging from 0.2% in Italy to 44.23% in Japan.A significant variation was noticed in the cross-sectional studies that examined anticholinergic use in PD.
In some Asian countries (India, Japan, and Singapore), anticholinergics prove more popular with a high prescription rate ranging from 22.9% in Singapore to 40.4% in India.

Trend of prescribing across yearsThere was an increase in L-dopa prescribing across time in Sweden, Spain, and Europe.
A decrease in L-dopa prescribing across time was observed in Southern Italy, Japan, USA, Finland, and Taiwan.
A general decrease in prescription rates of ergot DAs and an increase in the trend of non-ergot DAs prescription rates were observed in several countries especially after 2000.Prescribing increase was observed in the USA, New Zealand, and Japan. On the contrary, studies based in Australia, Europe, and Spain showed a slight decrease in prescribing.Selegiline prescribing was either maintained or decreased across years.
Only two studies revealed a slight increase of MAO-B inhibitors (Rasagline mainly) prescribed over time in Finland and Europe.
Across years, a relatively steady prescribing rate of amantadine was observed in the USA, Australia, and Europe.
A general decrease in prescription rates was seen in Japan, and an increase in the trend of prescription rates was observed in New Zealand.
Most studies have shown a decrease in prescription rates of anticholinergics across years

Patient factors
AgeElderly patients (age ≥ 65 years or age ≥ 70 years) were more likely to be prescribed L-dopa than younger patients.DAs use was less common in elderly patients with some exceptions as in some USA hospitals.N/AComparative Italian study that examined MAO-B users found that rasagiline utilisation was more common in younger patients than selegiline.N/AIn two studies, elderly patients were less likely to be prescribed or initiated on anticholinergics.
GenderMultiple studies found no difference between men and women in the likelihood of L-dopa prescribing.Multiple studies found no difference between men and women in the likelihood of DAs prescribing.N/AOne Italian study found that rasagiline was more commonly prescribed to men than selegiline.N/AN/A
RaceN/AIn USA, DAs prescribing was more common in non-Hispanic white people when compared to African Americans, although this finding was not statistically significant.In USA, COMT inhibitors prescribing was more common in non-Hispanic white people when compared to African Americans, although this finding was not statistically significant.In USA, MAO-B inhibitors prescribing was more common in non-Hispanic white people when compared to African Americans, although this finding was not statistically significant.In USA, amantadine prescribing was more common in non-Hispanic white people when compared to African Americans, although this finding was not statistically significant.N/A
Duration of the diseaseNumber of years since PD diagnosis was lower in L-dopa monotherapy users than DAs monotherapy users.Number of years since PD diagnosis was lower in L-dopa monotherapy users than DAs monotherapy users.N/AN/AN/AN/A
ComorbiditiesN/ADAs prescribing was more common in patients with a high comorbidity score.COMT inhibitor prescribing was more common in patients with a high comorbidity score.MAO-B inhibitor prescribing was more common in patients with a high comorbidity score.Amantadine prescribing was more common in patients with a high comorbidity score.Patients with PD and dementia were prescribed anticholinergics as initial therapy more commonly than non-dementia patients.
Socioeconomic status and care settingsL-dopa equivalent daily dose (LEDD) prescribed to care home residents was lower than that prescribed to the patients in the community.Patients with a higher education level were prescribed DAs more often than patients with a lower education level.
Patients residing in institutions were less commonly prescribed DAs than residents within the community.
COMT inhibitor prescribing was higher in patients living in their homes compared to care homes patients.MAO-B inhibitor prescribing was higher in patients living in their homes compared to care homes patients.N/AN/A
Geographical locationOne Norwegian study found that patients living in Rogaland county were significantly prescribed more L-dopa intestinal gel than other counties in Norway.N/AN/AN/AN/AN/A
Prescribers’ factors
Type of prescriberIn USA, half of the family physicians and almost one third of the neurologists prescribe L-dopa as a starting therapy for PD patients immediately after diagnosis.
In Spain, no significant difference was found in the percentages of prescribers of L-dopa among family physicians, geriatricians, neurologists, and movement disorder specialists.
In Spain, movement disorders specialists tended to prescribe DAs more than general practitionersN/AN/AIn Spain, movement disorders specialists tended to prescribe amantadine exclusively.In the USA, mental health providers were more likely to prescribe anticholinergics as an initial therapy than other prescribers.
In Spain, the percentage of patients treated with anticholinergics was higher if they were treated by family physicians