February 2016
clinical initiatives, research and current updates in treatment
Elastomeric infusion devices in cancer treatment: a brief guide Thomas Wong, River City Pharmacy, Icon Cancer Care In the day-hospital setting, when intravenous chemotherapy is given as a continuous infusion, the use of an ambulatory infusion device is indispensable. This article will explore the rationale of why chemotherapy is given as a continuous infusion, ambulatory infusion devices in general and will then focus on elastomeric devices: how they work, their advantages, disadvantages and then some tips and troubleshooting.
Why is chemotherapy given as a continuous infusion? Chemotherapy is given as a continuous infusion in an attempt to increase anti-tumour activity and also to reduce its toxicity.1 Administering by continuous infusion: ¬ ¬ Increases the exposure of cancer cells to chemotherapy agents with a short half-life e.g. cytarabine 1 ¬¬ Increases the likelihood of exposure to cancer cells when they are in the specific targeted phase for cellcycle specific chemotherapy agents e.g. cytarabine is S-phase specific
¬¬ Increases the duration of exposure to cancer cells results in increased effectiveness of some chemotherapy agents e.g. methotrexate ¬¬ Reduces acute toxicities e.g. fluorouracil and mucositis and neutropenia 1 ¬ ¬ Enables more dose intense schedules to be given e.g. fluorouracil Ambulatory infusion devices enable patients requiring continuous infusion chemotherapy to be treated on an outpatient basis. Without these devices, more frequent and longer hospital admissions would be required, reducing patient quality of life and increasing costs for the health system.1
Ambulatory infusion devices There are many different ambulatory infusion devices available on the market. Broadly speaking ambulatory infusion devices can be divided into battery-driven pumps (e.g. CADD pumps) and self-driven pumps (e.g. elastomeric devices). The most common elastomeric devices are the Baxter range and these are called Infusors and Folfusors (see figure 1).
Figure 1: Baxter Folfusor device
How do elastomeric devices work? With an elastomeric device, the drug is held in a stretchable balloon reservoir and the elastic wall of the balloon creates the pressure which drives drug delivery (see figure 2).2 The flow rate is determined by a flow restrictor that is located at the end of the tubing. The flow restrictor is a piece of tubing with a smaller bore (diameter) than the tubing. The smaller bore increases the pressure gradient and thereby slows the rate of flow of drug out the tubing.3
Factors which affect the flow rate of elastomeric devices There are a number of factors that can affect the flow rate of elastomeric devices, making it faster or slower, and these include: ¬¬ Height; if the device is lower than the flow restrictor, the flow rate will decrease, and conversely will increase if the device is above the flow restrictor ¬¬ Initial filling volume; if the device is under filled (<80%) the flow rate will increase and will decrease if filled close to its maximum allowed volume Continued on page 2
Continued from page 1 ¬¬ Temperature; taping the flow restrictor to the patient’s torso is ideal, if taped to a peripheral limb, the temperature, and therefore the flow rate, will be slightly lower ¬¬ Fluid type; elastomeric devices are calibrated for use with 5% glucose, using 0.9% sodium chloride will result in a flow rate approximately 10% faster.4 ¬¬ Access system/catheter size; needs to be at least 22 gauge (or larger) or the flow rate will be decreased
What are some of the advantages of elastomeric devices
(10-12.5% variance for Baxter Infusors and Folfusors 4 as opposed to 5% for electronic pumps) 3 ¬ ¬ Not possible to administer varying dosing schedules as only continuous infusions can be given e.g. not possible to give 2 bolus doses twelve hours apart ¬ ¬ Number of available infusion rates is limited 3 ¬ ¬ Maximum reservoir volume is 300mL 4 ¬ ¬ Flow rate not able to be altered if required 3 ¬ ¬ Factors that affect the flow rate (see above)
¬¬ Much more convenient for the patient; smaller, quieter and lighter 3
¬ ¬ Careful selection of the appropriate elastomeric device required by pharmacy staff at time of preparation
¬¬ Baxter devices are metal-free so can be taken into MRI machines 5
Troubleshooting
¬¬ Eliminate potential programming errors by nursing staff ¬¬ Simple to use; connect and go 3 ¬¬ No need to charge or change batteries and no problems with flat batteries 5 ¬¬ No large initial cost outlay compared with electronic pumps ¬¬ Easier and quicker for pharmacy to prepare
What are some of the disadvantages of elastomeric devices
Sometimes, elastomeric devices may run a little fast or a little slow. If the elastomeric device is empty earlier than expected, check: ¬ ¬ Was there any direct heat source placed near the flow restrictor? ¬ ¬ Was the flow restrictor lower than the reservoir for a long period of time? ¬ ¬ Was the elastomeric device under filled (especially <60%)?5 If the elastomeric device infuses slower than expected, check: ¬ ¬ Where was the flow restrictor taped to the patient’s skin?
¬¬ Larger quoted variance in flow rate compared with electronic pumps
¬ ¬ Was the flow restrictor in contact with a cooling source?
¬ ¬ Was the flow restrictor significantly higher than the reservoir for a long period of time? ¬ ¬ Was the elastomeric device overfilled (close to 100% of the maximum allowed volume)?5 It is always important to educate the patient on any infusion device and the following are some points for nurses and pharmacists to include in that discussion: ¬¬ The balloon in the elastomeric device should reduce slowly over the infusion period, remind the patient to check on this periodically ¬¬ Try to wear the elastomeric device in the ‘bum bag’ provided and keep the reservoir as close to the flow restrictor in height as possible ¬¬ When sleeping – put the elastomeric device on top of the bed covers (not underneath) or on a bedside table5 or under your pillow 4 ¬¬ Showering – use the shower bag provided or hang the elastomeric device from the shower head/tap but avoid a direct stream of water6 (in the bath is also fine but don’t submerge) 4 Whilst there are some limitations and disadvantages to elastomeric devices there are a number of advantages and most importantly they are smaller, quieter and lighter making them much more convenient for the patient. The use of elastomeric devices enables efficient, safe and affordable administration of continuous chemotherapy in the ambulatory setting.
Figure 2: A Baxter elastomeric device Capping Assembly
Fill Port
Coil Cap
Flow Restrictor
Filter
Elastomeric Balloon
Winged Luer Cap
What’s new Management of fatigue in cancer patients Karen Kwong – Icon Cancer Care, River City Pharmacy The NCCN definition of cancer-related fatigue (CRF) is ‘an unusual persistent subjective sense of tiredness related to cancer or cancer treatment that interferes with usual function’.1 Compared with non-cancer related fatigue, it is not generally alleviated by sleep or rest. CRF is estimated to affect up to 90% of all cancer patients and more than 75% of those patients who have advanced disease or metastases.2 Those receiving any active treatment for their disease are at higher risk of developing fatigue. 3 A retrospective study showed that 91% of participants experienced fatigue that prevented a normal life and 88% indicated that the fatigue resulted in an alteration in daily activities.4 Given the impact of fatigue, regular and routine assessment should be considered to determine the presence and severity of symptoms to ensure prompt intervention and to minimise the impact on quality of life.
Screening and assessment of CRF It is recommended each patient receive a baseline assessment of CRF at initiation of therapy, at each chemotherapy visit and at the diagnosis of advanced disease.1 Many different tools have been tested for screening and assessing CRF, but none have been shown to be diagnostic. Diagnosis of CRF should be achieved through symptom-driven evaluations and elimination of treatable contributing co-morbidities should be considered. 5 These include: hypothyroidism, anaemia, pain, insomnia, electrolyte disturbances, side-effects of medications, metabolic imbalances and organ dysfunction.6 If CRF persists despite correction of these co-existing factors, or if they are not present, management options should be recommended.
Management of CRF Non-pharmacological options Most patients suffering from fatigue derive a benefit from nonpharmacological interventions.8 Comprehensive patient education about the following recommendations can help patients identify and manage CRF at home.
Exercise Physical activity has been shown to have a positive impact on fatigue, quality of life, functional capacity and emotional wellbeing during and after any anti-cancer treatment.5 For this reason, it should be the primary recommendation for patients suffering from CRF. Moderate intensity exercise is recommended but should be adjusted to suit each patient’s physical status and exercise capabilities. Brisk walking, swimming or cycling for 15 to 30 minutes three times a week can be recommended to patients. 9 For patients who request more guidance, or who have complicated co-morbidities, referral to a physiotherapist or exercise physiologist should be considered to ensure a safe and tailored treatment program.
Energy conservation techniques Studies have demonstrated that cancer patients felt that they could only accomplish 55% of daily activities when feeling fatigued.4 Energy conservation involves the deliberate planned management of the patient’s energy resources to prevent or minimise their depletion.10 A diary has been shown to be useful to map out periods of maximum energy where essential tasks should be accomplished. Patients should be reassured that nonessential activities can be postponed or delegated. A multi-site clinical trial involving 296 patients demonstrated significantly lower levels of CRF
in patients who were educated on and practiced energy conservation techniques.10 The following are useful recommendations:11 ¬¬ Plan out your day and incorporate rest breaks ¬¬ Have several short naps throughout the day as opposed to one long rest period ¬¬ Sit down to complete daily activities (e.g. showering, dressing and undressing, chores) ¬¬ Minimise bending or stretching and avoid heavy lifting ¬¬ Choose clothing that is non-iron and easy to put on and take off ¬¬ Choose long-handled household items and install rails and handles where required ¬¬ Grocery shop during off-peak times and choose delivery if possible ¬¬ Eat small meals and snacks throughout the day to replenish energy ¬¬ Keep a supply of frozen meals at home for days when cooking is difficult ¬¬ Keep a supply of ready to eat snacks at home and for outings
Psycho-social interventions Several meta-analyses have shown that patients with CRF can benefit from some type of psycho-social intervention.1 These include: individual and group counseling, stress reduction, relaxation training, formal cognitive behavioural therapy, fatigue related psycho-education and supportive interventions.5 Therapies that specifically concentrate on fatigue have been shown to be more effective than general interventions.12 Continued on page 4
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New Drug Brief Vortioxetine Vortioxetine is a new antidepressant thought to produce an antidepressant effect by directly affecting several serotonin receptors and inhibiting the serotonin transporter.1 It is indicated for the treatment of major depressive disorder in adults, including the prevention of relapse. Vortioxetine is not currently listed on the PBS.2
and its superiority over placebo.2,4,5 These studies also included an active comparator arm. In one study, 5mg and 10mg doses of vortioxetine were directly compared to venlafaxine 225mg/day. Changes in depression scores (MDRS, HAM-D17, HAM-D24) did not reach statistical significance.4,6 However, direct comparison of duloxetine 60mg/daily with vortioxetine 15mg/day and 20mg/day identified duloxetine as superior in improving depression rating scales (MDRS, HAM-D17, HAM-D24). 2,6
Three recent trials have been completed and established the safety and efficacy of vortioxetine
The recommended starting dose of vortioxetine is 10mg/day increasing up to 20mg/ day according to patient
Felicity Matthews, Epic Pharmacy Geelong
Management of fatigue in cancer patients Continued from page 3 Sleep hygiene education helps to promote a good night’s sleep and optimise functional capabilities. Good sleep hygiene habits include:11 ¬¬ Establishing a regular sleep pattern by getting up and going to sleep at the same time every day ¬¬ Adhering to sleep restrictions by limiting daytime naps to 20 to 30 minutes ¬¬ Avoiding caffeine after midday
Pharmacological options Studies have shown that patients suffering from moderate-tosevere fatigue may benefit from pharmacologic treatments in combination with non-pharmacologic therapy, especially if quality of life or the ability to carry out daily activities is impaired.5 Available literature explores the use of psychostimulant options such as methylphenidate which has been shown in some small trials to be superior to placebo in improving anxiety, appetite, nausea,
pain, drowsiness and cognitive and functional abilities. Unfortunately, methylphenidate failed to show a benefit in the only randomised controlled trial completed bringing into question its usefulness in the management of CRF.13 Corticosteroids have been used in palliative settings to help alleviate pain and increase appetite, which may in turn improve CRF.1 Some clinical practice guidelines suggest that corticosteroids may be trialed as they have shown a small beneficial effect in overall quality of life and fatigue.13 Several open label trials have been conducted to assess the efficacy of other agents such as anti-depressants, erythropoietin-stimulating agents, L-carnitine and multivitamins.14 These trials were small, varied in quality and failed to demonstrate any significant benefit in improving CRF. Trials exploring the use of pharmacological agents in the treatment of CRF have been limited
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response. For those older than 65 years, vortioxetine should be initiated at 5mg, and increased up to 20mg if necessary. Vortioxetine is metabolised by CYP2D6 and the dosage may require adjustment in patients taking a CYP2D6 inducer or inhibitor. There is no dose alteration required in renal or hepatic impairment. Nausea and headache are the most common side effects associated with vortioxetine.7 The limited clinical data establishing vortioxetine as comparable to current therapy, the cost and lack of treatment experience currently makes vortioxetine’s place in therapy unclear.6
by sample size and trial design. Larger placebo-controlled randomised trials are required to verify the results of these small studies before they can be considered for recommendation in a clinical setting.14 CRF impacts almost all cancer patients, especially those receiving any type of active treatment. Management strategies should focus on identification and treatment of underlying contributing causes1 and education on non-pharmacological options. Pharmacological therapies lack definitive supporting evidence and should be reserved for patients suffering from severe CRF who have failed multiple therapies. Non‑pharmacological treatments such as exercise and energy conservation can be safely recommended to most patients and are endorsed by both the NCCN and ASCO guidelines.1,15 Nurses and pharmacists already play an important role in all aspects of patient care and are in an optimal position to screen for and evaluate CRF and provide basic education and counseling on management strategies.
If you have any queries regarding Circuit content and authors please contact the Epic Pharmacy Practice Unit by email: circuit.editor@epicpharmacy.com.au Every effort has been made to ensure this newsletter is free from error or omission.
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