Detailed Case Discussion on Movement Disorders - Parkinson's Disease

1. Parkinson’s disease
Discussion by ShivankanKakkar, MD
Long Case
Day 1
Mr LN, a 67-year-old retired IAS Officer, was admitted to the
neurology ward. His presenting complaints included difficulty in
getting up from chairs and initiating walking. Eighteen months earlier
he had noticed that his self-winding watch, which he wore on his

2. right wrist, was consistently losing time. When moved to his left
wrist, the watch kept perfect time. Friends had pointed out that he
had developed a limp, dragging his right foot. These symptoms had
worsened over the previous 18 months, and he had also developed
a resting tremor in his right hand and leg. He had noticed changes
in his bowel habits many years previously. His general practitioner
(GP) suspected Parkinson’s disease and referred Mr LN to a
neurologist for confirmation of the diagnosis.
Q1 What are the main symptoms of Parkinson’s disease?
Q2 Is it possible to make a definitive diagnosis of idiopathic Parkinson’s

3. disease (IPD)?
Q3 What biochemical defects are thought to be present in a patient such
as Mr LN?
Q4 Outline a treatment care plan for Mr LN.
Q5 Which drugs are usually considered for the initial treatment of
patients with IPD and what are their modes of action?
Day 2 Mr LN was started onropinirole.
Q6 Do you agree with this choice?
Q7 How should Mr LN’s ropinirole therapy be adjusted to optimise
his response?
Q8 What counselling points would you highlight to a patient
commencing ropinirole?

4. Day 13 Mr LN was discharged on ropinirole 500 micrograms three times
daily and instructed to titrate the dose as directed. Mr LN’s GP was sent
a letter describing his recent admission and advice on how to titrate the
dose of ropinirole further.
Month 18 Mr LN was admitted for reassessment. Despite never
completely abating, Mr LN’s symptoms of bradykinesia and rigidity
had temporarily improved following initiation and up-titration of
ropinirole; however, recently Mr LN had experienced a worsening of
these symptoms, and his wife reported that he had become rather
obsessive about cleaning out the garden shed, performing this task

5. on an almost daily basis. On admission he was taking ropinirole 6 mg
three times daily.
Q9 What recommendations would you make with regard to Mr LN’s
drug therapy?
It was decided to start Mr LN on Sinemet Plus 125 mg three times
daily and simultaneously to reduce the dose of his dopamine agonist.
Q10 How can the adverse effects of levodopa be minimised?
Month 18, Day 8 Mr LN was discharged. He was now stabilised on

6. Sinemet Plus, two tablets three times daily, and ropinirole 4 mg
three times daily and had experienced a significant improvement in
his motor function.
Month 66 Mr LN was again admitted for reassessment. His therapy
and symptoms had remained stable on the Sinemet and ropinirole
until recently, when he had started to notice his arms shaking about 1
hour after each dose of Sinemet Plus. This lasted for about 45
minutes before stopping. Mr LN also complained of painful dystonic
cramps at night, which caused him to wake early most mornings. He
had attempted to counter this by taking an extra Sinemet Plus tablet
shortly before going to bed, which sometimes helped. His wife added

7. that he was becoming profoundly immobile up to 2 hours before his
Sinemet doses were due during the day. On examination he was
found to have a mask-like face and a resting tremor in both hands
and legs. ‘Cogwheel’ rigidity was found in all four limbs. He had
difficulty initiating speech and his voice was very quiet. He struggled
to rise from his chair, and had a characteristic ‘parkinsonian shuffle’
when walking. When his shoulders were pulled forward from
standing he staggered forward and had to be supported to stop him
falling.
Mr LN complained of occasional falls and was not confident to
leave the house. He relied on his wife to do everything for him. He

8. admitted to being depressed about his condition.
There was no other medical history of note. All routine laboratory
tests were within normal ranges. His drug therapy was ropinirole 4
mg three times daily plus two Sinemet Plus tablets at 8 a.m., 2 p.m.
and 7 p.m. and, occasionally, one Sinemet Plus tablet at11 p.m.
Q11 Which of the long-term complications of levodopa therapy is
Mr LN suffering from?
Q12 What alterations to Mr LN’s drug therapy would you recommend
in order to try to minimise these effects?
Q13 How could you monitor and assess Mr LN’s response to these changes?
Q14 Can you suggest any non-drug management that might benefit Mr LN?
Mr LN’s drug therapy was changed to one Madopar dispersible

9. 62.5 mgtablet on waking around 7 a.m., and one Sinemet Plus tablet
at 10 a.m., 1 p.m., 4 p.m. and 7 p.m. In addition, he was prescribed
one Sinemet CR tablet at 10 p.m. The nursing staff were asked to
complete an hourly ‘on– off’ chart.
Month 66, Day 6 Mr LN’s mobility and dyskinesias were improved;
however, he remained depressed about his condition.
Q15 Would Mr LN benefit from an antidepressant?
Q16 If so, which would you choose?

10. Completed on/off chart
Time Day 1 Day 5
7 a.m. off off (dose)
8 a.m. off (dose) on (dyskinesia)
9 a.m. on on
(dyskinesia)
10 a.m. on off (dose)
(dyskinesia)
11 a.m. on on (dyskinesia)
12 noon off on
1 p.m. off on (dose)
2 p.m. off (dose) on (dyskinesia)
3 p.m. on on
(dyskinesia)

11. Month 66, Day 8 Mr LN had noticed a significant reduction in the
shaking of his arms following his recent regimen change; however,
he was still becoming considerably immobile about 1 hour before his
dose of Sinemet. His sleep had improved so that he was getting at
least 6 continuous hours’ sleep and no longer woke in pain from
cramps. The consultant neurologist recommended commencing
entacapone.
Q17 Why has the consultant neurologist recommended entacapone,
and does this necessitate the adjustment of Mr LN’s other IPD
therapy?
Q18 What counselling points would you highlight to a patient
commencing entacapone?

12. Month 66, Day 11 During the ward round, you noted that Mr LN’s
morning medication was still on his bedside table. His medication
now comprised one Madopar dispersible 62.5 mg tablet on waking
around 7 a.m., one Sinemet Plus tablet at 10 a.m., 1 p.m., 4 p.m.
and 7 p.m. and a Sinemet CR tablet at 10 p.m. In addition, he was
taking one entacapone tablet alongside each dose of Sinemet Plus
and 3 mg ropinirole three times a day (made up of a 1 mg and a 2 mg
tablet for each dose). His regimen thus comprised a total of 16
tablets per day.
On questioning, Mr LN informed you that, although he was feeling
better, he was concerned at the number of tablets he was taking and

13. feared that he would have problems remembering to take them all
when he returned home. He also found the new tablet quite hard to
swallow because of its size.
Q19 In view of Mr LN’s concerns, what options are there for
rationalising his medications?
Month 75 Mr LN was admitted as an emergency by his GP, having
developed visual and auditory hallucinations over the previous week.
He was hearing voices talking about him, threatening to kill him. He
was also seeing insects crawling up the walls and burrowing into his
skin. On examination he was clearly distressed and very frightened.
His medication on admission was one Madopar dispersible tablet on

14. waking, one Stalevo 100/25/200 tablet four times daily, one Sinemet
CR tablet at night and oneropinirole XL tablet 8 mg daily.
Q20 Which drugs might have contributed to Mr LN’s symptoms? Q21
What adjustments would you recommend be made to Mr LN’s
medication?
Month 75, Day 7 The recommendations had been carried out.
Mr LN’s visual hallucinations had improved, but he was still
experiencing

15. distressing auditory hallucinations and the control of his symptoms had
deteriorated, such that he was experiencing frequent ‘off’ periods.
Q22 What course of action would you suggest to improve Mr LN’s symptoms?
Mr LN was started on rivastigmine 1.5 mg twice daily. The dose
was increased over the next 10 days to 4.5 mg twice daily. His
dopaminergic therapy was adjusted to one Stalevo 100/25/200
tablet five times daily, one Sinemet CR tablet at night and one
Madopar 62.5 mg dispersible tablet upon waking. His ropinirole XL
therapy was discontinued. His hallucinations resolved and acceptable
control of his Parkinson’s symptoms was achieved. He was
discharged on this regimen.
Q23 What is the long-term outlook for Mr LN?

16. The main symptoms in patients with Parkinson’s disease are tremor,
rigidity, bradykinesia (slowness of movement), akinesia (loss of
movement) and postural abnormalities.
What are the main symptoms of Parkinson’s disease?
A1
The onset of Parkinson’s disease is usually insidious and progression
slow. Many patients first notice a resting tremor. This usuallyinitially
affects the hands and may be unilateral. The tremor disappears on
movement and during sleep, and may be worse under stress. The
patient is usually over 50 years old on presentation.
Rigidity manifests as an increased resistance to passive movement

17. and is classically termed ‘cogwheel’ rigidity, with a ratchet-like phe-
nomenon felt at the wrist on passive movement of the hand.
Bradykinesia manifests as a general slowness in movement.
Together with the rigidity, it is responsible for the typical
abnormalities of gait: difficulty in starting and finishing steps,
resulting in shuffling; a stooped head; flexed neck, upper extremities
and knees; and a lack of normal arm swing. A wide range of non-
motor symptoms (NMS) have also been described in Parkinson’s
disease, all of which can have a significant impact on quality of life.
These include bowel and bladder problems, fatigue, pain, sleep
disorders and autonomic dysfunction, in addition to difficulty in
swallowing and speech alteration, drooling of saliva and olfactory

18. disturbance. Loss of postural reflexes leads to postural imbalance and
sometimes to frequent falls. NMS are common and can occur at all
stages of Parkinson’s disease, including long beforediagnosis.
Symptoms increase in number and severity as the disease progresses.
Until recently, there has been a tendency for healthcare professionals
to overlook these features in favour of the more apparent motor
symptoms.
Is it possible to make a definitive diagnosis of idiopathic
Parkinson’s disease (IPD)?
A2 At present the only way of making a definite diagnosis of IPD
is by postmortem study of the brain.

19. IPD is the most common cause of parkinsonism, accounting for
approxiimately 75% of cases presenting to neurologists. Other causes
include other neurodegenerative diseases such as progressive
supranuclear palsy (PSP) and multiple system atrophy (MSA),
intoxication with heavy metals, treatment with therapeutic drugs
(neuroleptics, metoclopramide) and chronic cerebrovascular disease.
The definitive diagnosis of Parkinson’s disease is based on
characteristic neuropathological findings of Lewy bodies and
neuronal loss in the substantia nigra and other brainstem nuclei.
Studies have shown that only 65– 75% of patients diagnosed as
having early Parkinson’s disease had the characteristic findings at
postmortem.

20. Current opinion and guidelines recommend that all patients with
a ‘suspected’ diagnosis of IPD must be referred untreated to a
specialist who can reliably differentiate between IPD and other
parkinsonian syndromes. Previously the response to a ‘challenge’ of
levodopa or dopaminergic agents has been used for diagnostic
purposes; however the National Institute for Health and Clinical
Excellence (NICE) guidance for Parkinson’s disease does not
advocate that this be performed routinely, although guidelines vary
worldwide. Acute challenge testing is similar to, but not better than,
chronic levodopa therapy in terms of diagnostic accuracy, but is
associated with adverse effects and extra costs.

21. The use of imaging techniques is increasing in this field. Single
photon emission computed tomography (SPECT) with DatSCAN, a
radi- olabelled cocaine derivative, can be used to measure the
amount of dopamine-releasing neurones in the brain. This type of
imaging can aid differentiation between parkinsonian and non-
parkinsonian syndromes, but it is unable to distinguish between IPD,
MSA and PSP.

22. What biochemical defects are thought to be present in a patient
A3
such as Mr LN?
Several biochemical defects are thought to be present in
patients with Parkinson’s disease.
A combination of cholinergic (excitatory) and dopaminergic
(inhibitory) mechanisms acting in the striatal tracts of the basal
ganglia of the brain are thought to be responsible for the smooth
control of voluntary movements.
Imbalances in the neurotransmitters lead to movement disorders. In
patients with Parkinson’s disease, dopamine concentrations in the
three major parts of the basal ganglia are reduced to a fraction of

23. normal. Compensatory mechanisms operate and symptoms are not
noted until a severe loss (80%) of dopaminergic neurones has
occurred. The severity of some symptoms, such as bradykinesia, has
been found to correlate with striatal dopamine levels; however,
abnormalities of other neurotrans- mitters, including norepinephrine
(noradrenaline), 5-hydroxytryptamine (serotonin) and gamma-
aminobutyric acid, have also been reported. The full relevance of
these changes is unclear.

24. Outline a treatment care plan for Mr LN.
A4 Thegoals of symptomatic drug treatment are to help the patient
function independently for as long as possible, and to achieve
this with the minimum of adverse effects.
Patients with Parkinson’s disease have a chronic deteriorating condition
which will result in lifelong drug therapy of increasing complexity.
A long-term treatment care plan would include:
(a) Involving Mr LN in the choice of appropriate initial therapy.
(b) Ensuring the development of appropriate treatment outcome
mea- sures and a suitable treatment-monitoring programme.
(c) Ensuring that the patient understands the role of drugs inthe

25. symptomatic treatment of the disease and their possible adverse
effects.
(d) Ensuring that the patient and carers understand the importance
of adherence and timing of drug doses.
(e) Anticipating problems such as the potential for nausea and vomiting
with levodopa preparations, and offering appropriate advice on their
prevention.
(f) Counselling the patient and carers about drugs that should be
avoided in Parkinson’s disease. These include medicines which act
as dopamine antagonists, such as metoclopramide and the older
antipsychotics (e.g. chlorpromazine, haloperidol).
(g) As the disease progresses and more drugs are added to the

26. regimen, medicine taking may become problematic and advice on
methods for improving and maintaining adequate adherence
should be given.
(h) As most patients with IPD will be elderly, the general considerations
given to elderly patients should also be applied.
As treatment may continue for many years and become increasingly
complex, continuity of pharmaceutical care is an issue and
consideration should be given to a personal, individualised patient
record that can be used by pharmacists at various stages of the
disease. The Non-pharmacological considerations include education on
the disease itself, advice on diet, exercise programmes, and other areas
such as driving, alcohol intake and recreational activities.

27. Which drugs are usually considered for the initial treatment of
patients with IPD and what are their modes of action?
A5 Initial drug therapy as recommended by NICE guidelines forboth
early- and late-onset IPD will usually be chosen from the
following: levodopa preparations; a dopamine agonist; or a
monoamine oxidase B inhibitor (MAOBI).
There is still considerable debate about the best initial choice of
therapy for patients with IPD, and also when to start symptomatic
treatment. Most experts now advocate early treatment to provide
patients with maximal clinical benefit at the start of their illness.
Most Parkinson’s disease specialists start treatment when a patient’s

28. symptoms begin to interfere with their lifestyle. What constitutes
this will vary from patient to patient, but may include impairment of
activities of daily living (ADL), threatened loss of employment or gait
disturbance with a risk of falling.
When a decision is made to initiate treatment, the age of the
patient, the degree and type of symptoms and the patient’s
expectations will influence drug choice. Patients should be made
aware that drug treatment can provide symptomatic relief, but that
there is at present no way of halting the progression of the disease.
Levodopa is the most effective drug in the symptomatic management
of Parkinson’s disease, and virtually all patients will experience
meaningful benefit; however, it can cause significant short- and long-

29. term adverse effects.
The rationale for early use of dopamine agonists is that they
provide some benefit in early disease, but are significantly less likely
to lead to the development of motor complications, particularly
dyskinesias. Recent studies comparing levodopa with pramipexole in
early disease have shown that levodopa more effectively manages
motor symptoms, but is related to a greater incidence of motor
complications. Treatment withdrawal through adverse effects (e.g.
somnolence and peripheral oedema) was higher in the pramipexole
group. The incidence of impulse control disorders with dopamine
agonists is reported to be around 17% and can have significant
impact. The once daily formulations of pramipexole and ropinirole

30. have an advantage not only in compliance, but also in managing
symptoms for young patients who are still working, and who donot
wish for the higher frequency of dosing required with levodopa.
While it is an individual decision between the patient and the
consultant, initiation of a dopamine agonist in patients who require
this but who still have relatively mild symptoms may be appropriate.
Patients with more severe symptoms and those over 70 (in whom the
development of motor complications is less likely) should probably
be started on a levodopa preparation. Anticholinergic drugs are now
rarely used for the treatment of Parkinson’s disease. They provide some
relief of tremor but are of little value in the treatment of other features,
such as rigidity and bradykinesia. In addition, adverse effects are

31. common. These include peripheral effects such as dry mouth, blurred
vision and constipation, as well as potentially serious central effects,
including confusion and hallucinations. Their use is best reserved for
younger patients (under 60), in whom resting tremor is the
predominant feature. Anticholinergic drugs are thought to act by
correcting the relative central cholinergic excess brought about by
dopamine deficiency. They are not recommended as first-line treatment.
The MAOBIs selegiline and rasagiline selectively inhibit monoamine
oxidase B, one of the enzyme systems which break down dopamine.
The action of endogenous dopamine is thus augmented.
Selegiline has a mild antiparkinsonian effect and is sometimes used
either alone in early disease, or later to potentiate the action of

32. levodopa preparations. Selegi- line is metabolised to amfetamine
derivatives, so it may have an alerting effect, especially at night,
when it can cause insomnia, vivid dreams andnightmares.
Rasagiline, although very similar in chemical structure, isnot
metabolised to amfetamine derivatives and so is potentially free of
alerting side-effects. MAOBIs have been investigated for possession
of neuroprotective properties, but this has not yet been proven.
Dopamine deficiency cannot be rectified by the administration of
dopamine, because dopamine does not cross the blood– brain barrier.
Lev- odopa does cross the blood– brain barrier and is converted to
dopamine in the basal ganglia. Levodopa is thus thought to act primarily

33. by increasing brain dopamine concentrations. If levodopa is
administered alone, over 95% of a dose is decarboxylated to dopamine
peripherally, which results in reduced amounts being available to cross
the blood– brain barrier and problematic peripheral side-effects such as
nausea, vomiting and postural hypotension. Levodopa is therefore now
almost always administered with a dopa-decarboxylase inhibitor,
either carbidopa or benserazide.
These dopa-decarboxylase inhibitors do not cross the blood– brain
barrier and so smaller daily doses of levodopa can be administered,
thereby reducing the incidence of peripheral side-effects. Levodopa
therapy is particularly helpful in controlling symptoms of bradykinesia
or akinesia.

34. Do you agree with this choice?
A6 Yes. The choice of initial therapy is based on many different
factors that will vary from patient to patient. The useof a
dopamine agonist is indeed appropriate in this situation, as
would be the use of levodopa.
The dopamine agonists can be split into two different categories: ergot
and non-ergot. Ergot-derived dopamine agonists include the older-
generation products bromocriptine, lisuride, pergolide and cabergoline.
Non-ergot- derived agonists include the newer agents pramipexole,
ropinirole and rotigotine.

35. Use of the ergot-derived agonists has declined considerably over
the last few years as a result of increased concerns about long-term
side- effects, specifically cardiac fibrosis. There are clear monitoring
guidelines for patients who remain on these agents.
Critical appraisal of the literature evaluating the two non-ergot-
derived oral agonists provides no evidence to prefer one over the other.
Rotigotine, the transdermal patch formulation, although considered less
potent than the other non-ergot-derived dopamine agonists, provides
con- tinuous dopaminergic stimulation (CDS) over a 24-hour period.
Although it is suggested that 24-hour continuous drug release more
closely resembles endogenous dopamine release and may reduce the
risk of motor fluctu- ations and dyskinesias developing, there are at

36. present no firm clinical data to support this. Ropinirole XL and
pramipexole PR are also available as once-daily preparations. The initial
requirement to stabilise patients with immediate-release ropinirole prior
to starting once-daily (XL) has now been removed, and where local
formulary allows, prolonged-release formulations can be used from
initiation.
How should Mr LN’s ropinirole therapy be adjusted to optimise
his response?
A7 Like any dopaminergic therapy, ropinirole must be started ata
low dose and increased gradually in order to reduce the
incidence of side-effects and to establish the lowest effective
dose.

37. In order to facilitate gradual up-titration, ropinirole is available as a
‘starter pack’ that contains all the medication required for a stepwise
dose titration over a 4-week period. A ‘follow-on’ pack allows further
stepwise titration
over a similar period to a therapeutic dose. This dose can then be
further increased as required and tolerated by the patient.
Rotigotine patches are also available in a starter pack format.
Pramipexole doses are often referred to in both the salt and the base
form. It is important to be aware of this when referring to doses with
patients and other healthcare professionals; there are a number of
information materials available to aid patients and reduce confusion.

38. What counselling points would you highlight to apatient
A8
commencing ropinirole?
Patients should be warned about the potential for dopamine
agonists to cause impulse control disorders. In addition they
should be counselled on the risk of excessive daytime
somnolence and the implications of this on driving/operating
machinery.
What recommendations would you make with regard to Mr LN’s
A9
drug therapy?
Mr LN should at this stage be commenced on a low dose of
levodopa as an adjunct to the dopamine agonist. The dopamine
agonist dose should be reduced in view of his history of pund-

39. ing (the obsessive and repetitive perfomance of a useless task).
The levodopa dose should be gradually increased, with decisions
based on symptom relief and adverse effects.
Levodopa and dopa-decarboxylase inhibitors are marketed in the UK as
Sinemet (levodopa plus carbidopa: co-careldopa) and Madopar
(levodopa plus benserazide: co-beneldopa). There are six Madopar
preparations and six Sinemet preparations available in a variety of
levodopa strengths and formulations (standard, dispersible and
controlled release). The potential for confusion among clinicians and
pharmacists is considerable, and care must be taken to ensure that the
patient receives the intended preparation. At the start of levodopa

40. therapy the effects of a dose usually last for
4– 8 hours, so the tablets may be prescribed three times daily. The dose
should be increased by one tablet every 2– 3 days until optimum effects
are seen or adverse effects occur. If daily doses of <70 mg carbidopa are
used, the peripheral decarboxylase will not be saturated and Mr LN will
be more likely to suffer from nausea and vomiting. For this reason there
are low-levodopa Sinemet preparations containing 25 mg carbidopa plus
100 mg levodopa. There are also preparations containing 10 mg
carbidopa plus 100 mg levodopa that are suitable when higher levodopa
doses are needed. This is not a problem with benserazide preparations.
Most patients are initially controlled on 400– 800 mg levodopa daily.

41. Mr LN is beginning to display symptomsof punding. This is
charac- terised by repetitive pointless behaviours carried out for long
periods of time at the expense of all other activities, and is associated
with excessive dopaminergic stimulation. Punding and impulse
control disorders, for example compulsive gambling, can be
devastating and occur in up to 17% of patients treated with
dopamine agonists. The risk is higher in younger patients with a
history of addiction.
Punding is managed by reducing and discontinuing dopaminergic
stimulatory agents, predominantly dopamine agonists, although
levodopa is also implicated. In view of Mr LN’s worsening motor
function it is reasonable to reduce his dopamineagonist to manage

42. the side-effect of punding, and to supplement this with (initially) low
doses of levodopa in view of its superiority in improving motor
function. Abrupt withdrawal of dopamine agonists has been
associated with neuroleptic malignant syndrome and should
therefore be avoided. As there are no defined reduction regimens for
these agents, the rate of withdrawal can vary. In the case of Mr LN,
complete withdrawal may not be necessary and so slow reduction
would be appropriate, depending on symptom control. Reducing the
daily dose by 3 mg at 5-day intervals would be a reasonable regimen.
How can the adverse effects of levodopa be minimised?
A10 The peripheral side-effects of levodopa are significantly
reduced by combining it with a dopa-decarboxylase inhibitor

43. (see A5); however, peripheral side-effects may still occur.
Levodopa therapy is therefore best started at a low dose and
increased gradually. In addition, ensuring that the drug is taken with
or after food can reduce the incidence of nausea and vomiting still
further. Using domperidone, a dopamine antagonist that does not
cross the blood– brain barrier, can also reduce nausea and vomiting.
Doses of 10– 20 mg domperidone 1 hour before levodopa
preparations areeffective.
Which of the long-term complications of levodopa therapy is
Mr LN suffering from?
A11 End-of-dose akinesia and dyskinesias.

44. Initial treatment with levodopa leads to sustained improvement
through- out the day. Most patients will show a slow improvement in
response during the first 18– 24 months of treatment. Symptoms are
then ade- quately controlled for 3– 5 years. Unfortunately, after
long-term treat- ment (>5 years) only about 25% of patients continue
to have a good, smooth response. The main complications that
develop are fluctuations
in response, dyskinesias, psychiatric side-effects and partial or
substantial loss of efficacy.
Fluctuations in response initially consist of end-of-dose deteriora-
tion or end-of-dose akinesia. End-of-dose akinesia is the term used
when the therapeutic effects of a dose of levodopa are lost. This

45. commonly occurs first thing in the morning (after the longest dosage
interval) or just before or after a dose during the day, when the effect of
the previous dose wears off and before the next one is taken or
becomes effective. Patients may become immobilised and unable to do
anything except wait for the next dose. After prolonged treatment,
gradual deterioration in symptoms may begin between 1 and 3 hours
after a dose.
Long-term levodopa therapy is also associated with the ‘on– off’
phenomenon. The patient develops a sudden loss of effectiveness (off),
when ‘freezing’ occurs, which may last for only a minute or for up to
several hours before normal function returns (on).
Dyskinesias (abnormal movements) can occur in 60– 90% of patients

46. and are usually dose-related. They are generally worse when the
response to a dose is maximal (peak dose), and have been correlated
with high levodopa plasma levels. They are therefore commonly seen
after a dose has been taken. Symptoms include grimacing, gnawing and
involuntary rhythmic jerking movements.
What alterations to Mr LN’s therapy would you recommend in
order to try to minimise these effects?
A12 Increase the frequency of levodopa administration to 3-
hourly and reduce the amount given with each dose.
The most common approach to response fluctuation is to reduce each
individual dose of levodopa and to increase the frequency of
administration. This can reduce end-of-dose akinesia, but care must be

47. taken to ensure a clinical response is maintained.
End-of-dose bradykinesia or akinesia is thought to be caused by a
progression of the underlying disease or an unexplained occurrence
of symptoms of dopamine deficiency after an initial response to each
dose. Although there is no change in the plasma half-life of levodopa,
it appears that the pharmacological half-life is reduced. End-of-dose
akinesia has been shown to be corrected by levodopa infusion;
however, this is not a genuine therapeutic option, as levodopa must
be infused in large volumes, owing to its acidity, and it also
commonly causes thrombophlebitis. The initial approach taken to
minimise the end-of-dose effect is therefore to try to reduce the
dosage interval.

48. Modified-release versions of co-careldopa (Sinemet) and co-
beneldopa (Madopar) are available which result in a more prolonged
and
constant plasma level of levodopa. Both preparations lead to delayed
action and lower peak concentrations than standard levodopa, but
the risk of dose failure may be higher. Patients may still need to take
controlled-release preparations every 3 or 4 hours, and may need doses
of standard preparations to produce optimal clinical effects, especially
with the first dose of the day.
Dyskinesias may occur at the time of peak benefit, at the beginning
or end of a dose, or both (diphasic), or during ‘off’ periods. A reduction
in levodopa dose may reduce peak dose dyskinesias, as may the partial

49. replacement of levodopa with a dopamine agonist. Diphasic
dyskinesias may also be helped by partially replacing levodopa with
dopamine agonists. ‘Off’ period dyskinesia may be improved by
administering a fast- acting (e.g. dispersible) preparation or, for those
occurring in the early morning, a controlled-release preparation last
thing at night.
Other measures to improve consistency of absorption should also
be considered. This includes treating constipation (a common
problem in Parkinson’s) and reviewing medications which can slow
gastric emptying. Taking doses 1 hour before food (if tolerated) can
also be helpful. High- protein meals may also reducelevodopa
bioavailability because large neutral amino acids can compete with
levodopa for absorption.

50. How could you monitor and assess Mr LN’s response to these
A13
changes?
By charting his mobility regularly.
Some neurology wards use mobility charts on which an indication of
a patient’s mobility can be recorded at suitable intervals. Such charts
can be a valuable aid to the manipulation of drug administration in
order to optimise therapy. In addition to a score, a brief description
of the patient’s condition may be added.

51. Can you suggest any non-drug management that might benefitMr
A14
LN?
Mr LN may benefit from some remedial therapy, such as speech
and language therapy, physiotherapy or occupational therapy.
This should beavailable to patients with IPD and has been
endorsed in NICE guidance for IPD.
The role of these therapies is to maintain the maximum level of
functional mobility and capacity to perform ADL. Early therapeutic
intervention cannot reverse the course of Parkinson’s disease, but it
can delay potential deformity and functional decline.
Physiotherapy for Parkinson’s disease patients addresses the functional limitations
caused by rigidity and bradykinesia. It may include an

52. On No rigidity, mobilising
Off Rigid, with or without
tremor
Unable to mobilise or only
with assistance
On with dyskinesia No rigidity, mobilising but
with involuntary
movements
State Description
exercise programme that focuses on maintaining flexibility,
balance and strength.
Scoring system for patients with PD chart

53. Would Mr LN benefit from an antidepressant?
A15 Probably.
Depression is very common in Parkinson’s disease; approximately 40–
50% of patients suffer from depression at least once during the
course of their disease. Depression in Parkinson’s disease is
characterised by feelings of guilt, helplessness, remorse and sadness.
It is independent of age, disease duration, severity of symptoms or
cognitive impairment.
Ensuring adequate treatment for Parkinson’s disease should be the
first step before considering more specific antidepressant therapy. This
has been achieved in Mr LN, so a trial of an antidepressant would be
reasonable.

54. If so, which would you choose?
A16 A tricyclic antidepressant (TCA) or selective serotonin
reuptake inhibitor (SSRI) could be prescribed for Mr LN.
At present, there is insufficient evidence to recommend one antidepres-
sant/antidepressant class over another. This lack of data is also
highlighted in the NICE guidance. Clinical practice, as well as trial data,
supports the use of some TCAs (e.g. amitriptyline, nortriptyline) in
Parkinson’s dis- ease; however, they are often associated with
anticholinergic effects and orthostatic hypotension, which may limit
their usefulness. The SSRIs (e.g. fluoxetine, sertraline, citalopram)

55. have also been shown to be effective in Parkinson’s disease. They are
free of the anti- cholinergic effects associated with the tricyclics, and
theoretical concerns that they may worsen parkinsonian symptoms
have not been borne out by recent studies.
Why has the consultant neurologist recommended entacapone,
and does this necessitate the adjustment of Mr LN’s other IPD
therapy?
A17 Mr LN is still displaying signs of end-of-dose akinesia, despite
appropriate adjustment to his levodopa therapy. Entacapone
ther- apy may improve these symptoms, but his otherIPD
therapies will need to be adjusted as the drug is introduced.

56. Entacapone is a catechol-O-methyltransferase (COMT) inhibitor and
works in synergy with Sinemet and Madopar preparations, resulting in a
30– 50% increase in levodopa half-life. Entacapone works by inhibiting
the peripheral metabolism of levodopa by the enzyme COMT, thereby
increasing its availability to the brain. Entacapone is licensed for use as
an adjunct to levodopa in Parkinson’s disease. Studies have shown that
its use can significantly reduce ‘off’ time and increase ‘on’ time in
patients with ‘wearing-off’ episodes. It should be given at a dose of 200
mg with each dose of levodopa, up to 10 times daily. The introduction
of entacapone to a regimen can cause a new onset or worsening of
existing dyskinesias. In order to minimise this, the daily dose of
levodopa should be reduced by about 10– 30% by extending

57. the dosing intervals and/or by reducing the amount of levodopa per
dose. In practice, the choice varies from patient to patient.
Tolcapone, the only other commercially available COMT inhibitor,
differs from entacapone in that it also blocks centralCOMT.
Tolcapone was withdrawn in 1998 after a number of cases of
hepatitis, but has since been relaunched with strict monitoring
parameters and guidance onuse.

58. What counselling points would you highlight to a patient
A18
commencing entacapone?
Entacapone can discolour the urine reddish brown. Patients
should also be advised that nausea and vomiting can occur due
to augmentation of levodopa, and that diarrhoea is a common
adverse effect.
The large size of the tablets maycause problems for patients with
swallowing difficulties.

59. In view of Mr LN’s concerns, what options are there for
A19
rationalising his medications?
The use of combination products and alternative
formulations could be considered.
In the literature it has been noted that approximately 20% of
patients with IPD are non-adherent with their medication. Younger
patients and those with complex regimens are associated with the
highest levels of non-adherence.
A number of pharmaceutical companies have recently developed
combined preparations and modified-release preparations in an
attempt to reduce the patient’s ‘pillburden’.
Stalevo is a combined preparation of levodopa, carbidopa and

60. entacapone formulated into one tablet. A Stalevo tablet is smaller
than a tablet of entacapone alone andis thus also helpful in patients
with swallowing difficulties who require therapy. Stalevo is available
in a number of strengths, although dose titration is more limited
than with the individual components. Mr LN could be started on
Stalevo in place of Sinemet and entacapone.
The transdermal patch rotigotine and the oral formulations
ropini- role XL and pramipexole PR are designed for once-daily
administration. Rotigotine is particularly useful where swallowing
difficulties are trouble- some, or compliance with tablets is poor.
There are therefore a number of options for the rationalisation of
Mr LN’s medication regimen. A reasonable option would be to convert

61. each dose of levodopa/carbidopa and entacapone to one tablet of
Stalevo 100/25/200. Ropinirole could also be converted to the XL
preparation, as recommended in the Summary of Product
Characteristics, to one 8 mg tablet daily. These changes would more
than halve the number of tablets taken by Mr LN from 16 per day to
seven.
Which drugs might have contributed to Mr LN’s symptoms?
A20 All the drugs prescribed for Mr LN can cause the psychiatric
complications described.
Levodopa causes a variety of psychiatric symptoms, including
hallucina- tions. Dopamine agonists such as ropinirole can cause

62. central nervous system effects such as hallucinations and confusion.
These psychiatric complications are especially common in elderly
patients. In addition, progression of the disease itself may contribute
to these symptoms.
A21
What adjustments would you recommend be made to Mr LN’s
medication?
Gradually reduce his dose of ropinirole XL and stop ifnecessary.
The psychiatric complications of most antiparkinsonian drugs are
dose- related and often respond to a reduction in dosage.
It is generally recommended to reduce or eliminate

63. antiparkinsonian drugs in the following order, corresponding to their
relative propensity to cause psychiatric problems versus degree of
antiparkinsonian activity: anticholinergics, amantadine, MAOBI,
dopamine agonist, levodopa.
Mr LN’s dose of ropinirole should be reduced to the point of
improv- ing his hallucinations without drastically worsening his
parkinsonism, if possible. It should be reduced gradually, as sudden
withdrawal of dopaminergic agents may precipitate a neuroleptic
malignant syndrome. The levodopa dose should only be reduced if
hallucinations persist after elimination of all other antiparkinsonian
agents.

64. What course of action would you suggest to improve Mr LN’s
A22
symptoms?
Add a low dose of an ‘atypical’ antipsychotic drug, or consider a
cholinesterase inhibitor.
Haloperidol and chlorpromazine are effective antipsychotics but are
not recommended for Parkinson’s patients because of theircapacity
to block striatal dopamine D2 receptors and exacerbate
parkinsonism.
The newer ‘atypical’ antipsychotics (e.g. clozapine, olanzapine,
risperidone, quetiapine) are relatively free of D2-receptor-blocking
potential, and in principle should improve psychotic features without
worsening parkinsonism. The best studied of these is clozapine, which

65. has been shown to reduce hallucinations without worsening
parkinsonism. However, the potential for clozapine to cause
agranulocytosis (1 – 2% of patients) and the consequent rigorous
monitoring requirements often deter its use. Olanzapine and
risperidone have proved less effective than clozapine in comparative
studies, and have also worsened parkinsonism. The early work with
quetiapine was more hopeful; however, more recent controlled
studies have been negative. When quetiapine is considered, a starting
dose of 12.5 mg at bedtime is recommended and the dose should be
titrated upwards at 3– 5-day intervals until the desired
effect is achieved.
The cholinesterase inhibitors rivastigmine, galantamine and

66. donepezil, which were developed primarily for Alzheimer’s disease, have
been shown to reduce psychotic features and improve cognition in some
patients with Parkinson’s disease dementias. Most studies have used
rivastigmine and it is the only agent licensed for use in Parkinson’s
disease dementias. A relative cholinergic excess is already present in the
striatum of Parkinson’s disease patients, and thus the use of an agent
likely to support this imbalance further should only be undertaken under
specialist supervision.

67. What is the long-term outlook for Mr LN?
A23 It is likely that Mr LN’s condition will continue to deteriorate
with time, and that he will experience more ‘off’ time and
increasing dyskinesias. His cognitive function may also decline
further.
Amantadine has been used for the management of dyskinesias based
on its antiglutamate activity; however, its side-effects (confusion,
hallucina- tions) would preclude its use in Mr LN. Other side-effects
of amantadine include ankle swelling and livedo reticularis.
A small number of other therapies can be used at this stage in
patients with Parkinson’s disease, but their risks and financial
implications are considerable.

68. The use of apomorphine, a potent dopamine agonist licensed for
the treatment of refractory motor fluctuations (‘off’ periods) in IPD,
is a possibility in patients who deteriorate despite maximum
tolerated oral therapy. The drug cannot be given orally and must be
administered subcutaneously. It may be given as a continuous
subcutaneous infusion or as single injections. It causes severe nausea
and vomiting, so 3 days’ pretreatment with domperidone (20 mg
three times daily) is used to minimise this. Domperidone therapy
may be continued until tolerance to this side-effect develops.
Apomorphine is effective within 5– 10 minutes, and patients may
remain in the ‘on’ state for up to 60 minutes. During this time an oral
dose of medication should have taken effect. Many patients are

69. helped by up to five injections a day, although up to 10 may be
needed in some patients. If the number of injections needed ishigh,
then continuous infusions of apomorphine should be considered. If
the nausea and vomiting can be overcome, apomorphine therapy is
generally well tolerated. Bruising, nodules or abscesses may form at
the site of an infusion, so the site should be changed daily. As Mr LN
has had psychotic features in the past that resolved following
discontinuation of his dopamine agonist, the use of apomorphine
may not be appropriate and may further exacerbate this symptom.
The use of surgical techniques such as subthalamic deep brain
stim- ulation (STN-DBS) may also be precluded in Mr LN by his
previous psychotic symptomatology. The relatively high morbidity

70. and mortality rate associated with lesioning operations such as
thalamotomy and palli- dotomy has recently made STN-DBS more
favourable. STN-DBS involves the placement of tiny wires into the
subthalamic nucleus (STN). These emit continuous electrical impulses
from a neurostimulator, which is sim- ilar to a heart pacemaker. This
stimulation can have a positive effect on the brain activity involved
in controlling movement, and can improve tremor, stiffness,
slowness and dyskinesia. In addition, with improvement in these
symptoms medication can be reduced, thereby further reducing
dyskinesias. Mr LN may be an appropriate candidate for Duodopa, a gel
formulation of levodopa/carbidopa that is infused directly into the
duodenum. Duodopa is designed to mimic the pharmacokinetic profile

71. of endogenous dopamine release. The technique, albeit initiated using a
nasogastric tube, requires a percutaneous gastrostomy tube for long-
term administration. Such a procedure in patients with advanced
Parkinson’s disease can be hazardous.
Although there have been many recent advances in the
management of IPD, there is still no cure. Ongoing research is
targeted at neuroprotection strategies: interventions to protect or
rescue vulnerable dopaminergic neurones, and to slow down or stop
disease progression. Gene therapy trials are also currently under
way.