Palliative Care Flashcards
what is metoclopramide
an anti-emetic that mainly acts as a dopamine antagonist
often prescribed for nausea and vomiting related to reduced gastric motility
what is ondansetron
an anti-emetic that is a serotonin (5-HT3) antagonist
for chemotherapy-related nausea and vomiting
role of dexamethasone
steroid used to treat raised ICP
helps to alleviate headaches, nausea & vomiting, and neurological deficits
Once satisfactory improvements have been achieved, the dose should be weaned to the lowest effective dose
how long do fentanyl patches take to work
can take up to 72 hours to reach peak serum concentrations
why is oxycodone given in mild to moderate renal failure
It is metabolized in the liver to noroxycodone and oxymorphine and ten percent of unmetabolized oxycodone is renally excreted
even though noroxycodone and oxymorphone are renally excreted, their accumulation does not lead to any adverse side effects
role of opioids in palliative care
good control of pain & breathlessness
diamorphine vs morphine
Diamorphine is much more soluble than morphine and therefore easier to administer in higher doses.
It is also compatible with most other drugs which may need to be administered by a subcutaneous infusion. However, morphine is preferred in most cases as most people do not require doses large enough to cause solubility issues:
what anti-respiratory secretion medication is less likely to cause CNS side effects e.g. sedation
Hyoscine butylbromide and glycopyrronium bromide, do not cross the blood-brain barrier
breakthrough opioid drug doses
between 1/10 and 1/6
What is the approach for agitation and confusion in palliative care
Reversible or not
Reversible: think of PINCH ME
Pain
Infection
Nutrition
Constipation
Hydration
Medication
Environment
*** hypercalcemia, urinary retention
Medical treatment for confusion and agitation
First line: haloperidol
Then chlorpromazine, levomepromazine (6.25-12.5 for anti-emetic and 25 for sedative properties)
What drug is used in terminal phase of illness for agitation or restlessness
Midazolam
Causes of hiccups in palliative care
Gastric stasis and distension
GORD
Metabolic disturbances e.g. hypercalcemia, uraemia
Infection
Irritation of diaphragm or phrenic nerve
Hepatic disease/hepatomegaly
Cerebral causes e.g tumour
Management of hiccups
Chlorpromazine
- haloperidol, gabapentin also used
Dexamethasone is also used, particularly if hepatic lesions
What are hiccups
Diaphragm contracting involuntarily, causing vocal cords to shut and an abrupt increase of air into the lungs
2 main forms of morphine
MR (modified release) and immediate release
How to start patients on opioids
If no comorbidities, use 20-30mg of MR a day with 5mg for breakthrough pain e.g. 15mg 2x a day
What should be started in conjunction with strong opioids
Laxatives
**nausea is often transient, if persists than anti-emetic
Side effects of opioids
Constipation
Nausea
Drowsiness, confusion
Hallucinations
Pruritis
Dry mouth
Respiratory depression
*** opioids slow everything down
MOA of opioids
Act centrally in the PAG by enhancing descending inhibition
Opioids and patients with kidney disease
Mild to moderate: oxycodone
Moderate to severe: fentanyl, alfentanyl, buprenorphine
Treatment of metastatic bone pain
Strong opioids (lowest number needed to treat)
Bisphosphonates
Radiotherapy
Denosumab also
How much to increase dose of opioids by
30-50%
Or increase the dose by the amount of PRNs in the previous 24 hours
Transient and persistent opioid side effects
Transient = nausea, drowsiness (adjust dose accordingly for drowsiness)
Persistent = constipation
Conversion of codeine to morphine
/ 10
Differences between oxycodone and morphine
Oxycodone causes less sedation, vomiting, and priorities, but causes more constipation
What chemical released is involved in itchiness
Histamine
Conversion of oral morphine to sub cut morphine
/ 2
Conversion of oral morphine to subcut diamorphine
/ 3
Oral oxycodone to subcut diamorphine
/ 1.5
What are the secretions in palliative care
Build up of mucus and saliva at the back of the throat and airways
Patient weaker and unable to clear it
Management of secretions
Conservative: over fluid overload, stopping IV and subcut fluids
Educate family if distressed
Medical: hyoscine hydrobromide or hyoscine butylbromide (buscopan - may be less sedative)
Or glycopyrronium bromide
What type of drug are the anti secretory medications
Anti-muscarinic
What anti secretory medications might be less sedating
Hyoscine hydrobromide and glycopyrronium bromide
* don’t pass BBB
Category causes of nausea and vomiting
Reduced gastric motility
- can be opioid related
- related to serotonin and dopamine (D2) receptors
Chemical
- chemotherapy, opioids, hypercalcemia
Visceral/serosal
- constipation
- oral candidiasis
Raised ICP
- cerebral mets
Vestibular
- activation of acetylcholine & histamine receptors
- opioid related, motion related, base of skull tumours
Cortical
- pain, anxiety, fear, and/or anticipatory nausea
- Related to GABA and histamine (H1 receptors)
Drugs for nausea and vomiting
Reduced gastric mobility:
Metoclopramide (can cross BBB) and domperidone (pro-kinetic agents)
** metoclopramide normalises stomach mobility and acts directly on brain to reduce sensation of nausea
** not used in complete bowel obstruction, GI perforation or after gastric surgery
Chemical: correct disturbance
Or ondansetron, haloperidol, levomepromazine
Visceral/serosal: cyclizine, levomepromazine
Raised ICP
Dex
Cyclizine for nausea and vomiting (histamine receptor in cortex triggered by ICP)
Vestibular: cyclizine
Cortical: if anticipatory nausea, lorazepam or short acting BZD then cyclizine
Pathophysiology of vomiting
Vomiting centre in medulla
Close to vomiting centre in medulla is the chemoreceptor trigger zone. (CTZ) Have multiple receptors 5HT and D2
When these receptors are stimulated, stimulates muscarinic receptors of vomiting centre causing the reflex
1) CTZ located outside of BBB even though it is still part of the medulla , more permeable to circulating agents e.g. chemotherapy
2) When vestibular nuclei stimulated in motion sickness via vestibulocochlear nerve, H1 (histamine) and muscarinic receptors stimulated and pass signals to CTZ and then vomiting centre
3) Higher brain centres send signals to vomiting centre if emotional, pain, repulsive smell/sight - stimulate through muscarinic receptors
4) enterochromaffin cells in the gut release serotonin in response to cytotoxic agents, innervates vagus nerve to vomiting centre
These all cause relaxation of LOS, and causes diaphragm and stomach to contract
Increase salivation and tachycardia
Epiglottis closes
Route of anti-emetics
Oral is preferred
If vomiting, malabsorption, or severe gastric stasis, then parenteral can be used
When is a syringe driver used
In palliative care setting when patient unable to take oral medication due to nausea and vomiting, dysphagia, intestinal obstruction, weakness or coma
What is a syringe driver
Provides continuous medication over an hour or 24 hour period
Blue: delivery rate mm per hour
Green: mm per 24 hours
What is used for reducing discomfort of painful mouth
Benzydamine hydrochloride
What is common following radiotherapy to head and neck
Mucositis
Inflammation of oral mucosa, white lesions with central ulceration
When are transdermal patches recommended
Stable levels of pain who will not require regular titration of pain relief
Not always the case in palliative patients
Symptoms of raised ICP
Headaches, worse in mornings and better when standing
Nausea and vomiting
Blown pupils
Papilloedema
Neurological deficits
Occasional vision changes
Symptoms of opioid toxicity
Decreased consciousness
Pin prick pupils
Myoclonic jerks
