6   What is the nurse’s role in primary and secondary care with regard to helping Mr H comply with what could be a complex regimen of drugs?

7   What is the nurse’s role in primary and secondary care with regard to helping Mr H manage his dietary considerations while taking this group of medicines?

8   What are the reasons that ropinirole has been added to Mr H’s prescription and what are the potential side-effects?

9   How should his PD medicines be managed perioperatively?

ANSWERS

1 How is the movement of Mr H’s body normally controlled by the CNS?

A

•   The pyramidal motor system controls all of our voluntary movements. Pathological processes which damage the pyramidal motor system are extremely important causes of disability and suffering (Marieb 2010).

•   The pyramidal system is a major motor system comprising the axons that run through the corticospinal and corticobulbar tracts. Damage to either tract above the level of efferent cranial nerve nuclei will result in problems with the motor activity on the opposite side. For instance, if there is damage to the lateral area of one precentral gyrus, the muscle function of the face and oral cavities on the opposite side could be affected (Tate et al. 2008).

•   The extrapyramidal system is a neural network that is part of the motor system that causes involuntary reflexes and movement, and modulation of movement (i.e. coordination). The system is called ‘extrapyramidal’ to distinguish it from the tracts of the motor cortex that reach their targets by travelling through the ‘pyramids’ of the medulla.

2 What pathophysiology is underlying Mr H’s PD?

A PD is a progressive disorder of movement. Certain neurons in part of the brain called the basal nuclei degenerate and this leads to a lack of a neurotransmitter called dopamine. PD results from this greatly reduced activity of dopamine-secreting cells caused by cell death in the region of the substantia nigra. Typically, this disease occurs in people who are over the age of 50. The reduction in the release of dopamine causes the basal nuclei to become overactive and this overactivity presents itself in a number of ways (Barber and Robertson 2012).

3 Describe the four motor symptoms that Mr H is experiencing

A According to Jankovic (2008) there are four motor symptoms which are considered as being cardinal in PD: tremor, rigidity, slowness of movement and postural instability.

Tremor is the most apparent and well-known symptom. It is also the most common, although around 30% of individuals with PD do not have tremor at first but develop it as the disease progresses. A feature of tremor is ‘pill-rolling’, a term used to describe the tendency of the index finger of the hand to come into contact with the thumb and perform together a circular movement.

Rigidity is stiffness and resistance to limb movement caused by increased muscle tone – an excessive and continuous contraction of the muscles. In PD the rigidity can be uniform (lead-pipe rigidity) or ratchet-like (cogwheel rigidity). With the progression of the disease, rigidity typically affects the whole body and reduces the ability to move.

Slowness of movement (bradykinesia) is is associated with difficulties along the whole course of the movement process, from planning to initiation and finally execution of a movement. Performance of sequential and simultaneous movement is hindered. Bradykinesia is not equal for all movements or times. It is modified by the activity or emotional state of the subject, to the point that some patients are barely able to walk and yet can still ride a bicycle (Samii et al. 2004).

Postural instability is typical in the late stages of the disease, leading to impaired balance and frequent falls, and secondarily to bone fractures. Instability is often absent in the initial stages, especially in younger people. Up to 40% of patients may experience falls and around 10% may have falls weekly, with the number of falls being related to the severity of PD (NICE 2006).

4 Outline the mode of action of levodopa and suggest what the main side-effects of this medicine might be for Mr H

A MODE OF ACTION

SIDE-EFFECTS

Two major side-effects are associated with giving levodopa. In dyskinesia the individual develops a series of involuntary movements, causing acute embarrassment as they usually affect the face and limbs. If the dose is lowered, the dyskinesia does stop, but is replaced by the rigidity it had improved. This is a fine line that the patient and doctor walk in order to accept the consequences of both illness and treatment (BNF 2012). With the ‘on–off’ effect, quite suddenly the drug therapy seems to stop working. This can be quite distressing for the patient and can sometimes occur when they are in the middle of doing something. The reason for this fluctuation is not fully understood; however, patients should be made aware of both these side-effects when commencing treatment (Brenner and Stevens 2009).

Short-term side-effects quite often improve over a period of time. The person may feel sick, have no appetite and suffer a slight drop in blood pressure. This decrease in blood pressure could have a more serious effect if the patient is having antihypertensive therapy. A small number of patients may develop delusions and hallucinations as the brain is given extra dopamine which is thought to mimic the high levels found in patients with schizophrenia (Greenstein 2008).

5 What is the nurse’s role in primary and secondary care with regard to helping Mr H manage his timing of doses?

A

•   To get the right balance between benefit and any side-effects, you will need to educate and involve Mr H about which drugs are being used and why drug timing is so important in order to achieve continuous dopaminergic stimulation (CDS) for the optimal control of symptoms and to reduce the incidence of motor complications (Findley et al. 2009).

•   When admission to a home or ward occurs, it is important for staff to be aware of why the timing of these drugs is so important and to make sure medication times are accurately documented.

•   When going away, Mr H should ensure he has enough medication supplies and have worked out a transient timing regime with his doctor or specialist nurse to deal with different time zones or long-haul flights (Thomas and MacMahon 2002).

•   Mr H may exhibit an increase in libido and hypersexuality or pathological gambling associated with dopamine agonist treatment – this is referred to as an impulse control disorder. Its management is complicated and you should be aware of the syndrome in order to provide appropriate management and support (Giovannoni et al. 2000).

A

•   Nurses have an important role not only in sharing their knowledge with the person with Parkinson’s and their carer but also in encouraging patients to take responsibility for their health and well-being (DH 2005).

•   Selective information is usually more helpful and the Parkinson’s Disease Society has many publications that can help Mr H and his family understand more about PD and the drugs used to treat its symptoms.

•   Mr H must be taught to recognize the symptoms of PD and the side-effects of drug treatments in order to become ‘expert’ in managing his condition, and you, as the nurse, are ideally placed to help with this (DH 2005).

•   Compliance with drug regimens will suffer if Mr H does not understand drug side-effects or the different symptoms of the condition and how they respond to the drugs (Parkinson’s Disease Society 2007).

•   Mr H can be encouraged take part in his local expert patients programme, which may help him to manage his symptoms (DH 2001).

7 What is the nurse’s role in primary and secondary care with regard to helping Mr H manage his dietary considerations while taking this group of medicines?

A

•   You should advise Mr H to read the manufacturer and pharmacy information sheets, and that he should take his drugs after food, in order to help alleviate the common early side-effects of nausea and vomiting.

•   Some people need to take an antiemetic. Domperidone is the only oral antiemetic recommended for people with Parkinson’s, as it does not easily cross the blood–brain barrier and block dopaminergic receptors, causing extrapyramidal symptoms (i.e. symptoms of PD) (Downie et al. 2008).

•   It is recommended that the L-dopa be taken not less than 30 minutes before or 60 minutes after meals (Karch 2010).

8 What are the reasons that ropinirole has been added to Mr H’s prescription and what are the potential side-effects?

A

•   Dopamine agonists such as ropinirole have shown beneficial effects as adjunctive therapy to reduce ‘wearing off’.

•   Ropinirole adds clinical benefit in PD patients with motor fluctuations and also permits a reduction in the dosage of levodopa.

•   Side-effects of dopamine agonists include ankle oedema, hallucinations, somnolence and impulse control disorders. These effects should be discussed with patients before instituting therapy, and therapy should be discontinued if any of them occur (Clayton 2009).

A

•   Abrupt withdrawal of these medicines can lead to a potentially lethal condition called Parkinsonism-hyperpyrexia syndrome (PHS), which is clinically similar to neuroleptic malignant syndrome (Factor and Santiago 2005).

•   Even brief interruption of medications can lead to decompensation of Parkinsonian symptoms, which not only delays recovery from surgery but also increases the risk for multisystem complications.

•   Traditional anti-Parkinsonian medications can only be delivered orally, presenting significant challenges for nil-by-mouth patients, especially those undergoing enteric surgery requiring bowel rest (Serrano-Dueñas 2003).

•   The usual drug regimen should be administered as close to the beginning of anaesthesia as possible. L-dopa can only be administered enterally and its half-life is short (1–3 hours). It is absorbed from the proximal small bowel and therefore cannot be given as a suppository (BNF 2012).

•   Patients should be able to take L-dopa either with sips of water or by nasogastric tube. Another strategy is to use subcutaneous administration of apomorphine. However, this is very emetogenic and patients usually need to take domperidone for several days before an apomorphine challenge. Nevertheless, small doses of apomorphine with sufficient antiemetic cover may be helpful (Nicholson et al. 2002).