Nausea and Vomiting Management Flashcards
What is nausea?
Nausea is an unpleasant feeling of the need to vomit associated with autonomic symptoms (pallor, sweating, tachycardia, salivation)
What is vomiting?
The forceful propulsion of gastric contents through the mouth
What should you ask about in the history for a cancer patient with nausea and vomiting?
When did it start? Has it been constant or improved? What did it look like? Was there any blood in the vomit? How did it start? Has this happened before? how has it been treated if it has happened before Has anything helped to make it better or worse
How should you manage a patient complaining of nausea and vomiting?
Identify and correct any reversible causes- e.g. hypercalcemia, uraemia, GI infection
Non-pharmacological methods- avoid triggers, small frequent meals, ginger, mint
Pharmacological- Prescribe an anti-emetic
Correct any prescribing issues- PO route may no longer be suitable. Identify possible drug causes.
What are syringe drivers?
Syringe drivers are used for continuous subcutaneous infusions of drugs. This therefore gives continuous delivery via an alternative route to PO. They allow for rapid control of symptoms and easy dose adjustments by adjusting the drive rate.
What are some commonly used antiemetics?
Metoclopramide Cyclizine Haloperidol Ondansetron Levomepromazine
What are the symptoms of gastric stasis?
Feeling of epigastric fullness Early satiety Large volume vomits Hiccups Regurgitation Nausea quickly relieved by vomiting
What causes gastric stasis?
Drug side effects- anticholinergics, opioids
Gastric outflow obstruction- tumour, hepatomegaly, ascites
Gastritis
How should gastric stasis be managed?
Reduce intake to little and often
Reduce gastric secretions- PPI or H2 antagonist (Ranitidine)
Prokinetic agent: Dopamine Antagonists e.g. Metoclopramide, Domperidone
What is metoclopramide, how does it work?
Metoclopramide is an antiemetic that works as a prokinetic agent.
It is a D2 receptor antagonist and 5-HT4 agonist
Metoclopramide crosses the blood brain barrier so can worsen parkinson’s and cause EPSEs
What is the usual dose of metoclopramide?
10mg TDS PO
What are some side effects of metoclopramide?
Metoclopramide crosses the blood brain barrier. It can therefore cause EPSEs and worsen parkinson’s disease.
Caution in younger patients as there is a risk of oculogyric crisis.
What is an alternative to metoclopramide that does not cross the blood brain barrier?
Domperidone- this should be used in patients with parkinson’s or who develop EPSEs
Why does chemotherapy cause nausea and vomiting?
Chemotherapy targets cells with a rapid turnover, such as the GI mucosa. This is reduced when chemotherapy is taken and so there is irritation of the GI tract which causes nausea and vomiting.
What agent should be used to treat chemotherapy related nausea?
Ondansetron should be used
How does ondansetron work?
Ondansetron is a 5-HT3 antagonist
When should ondansetron be used?
Post chemotherapy
Post radiotherapy
Post surgery
What are two side effects of ondansetron?
1) Causes constipation- give laxative too
2) QT prolongation
How does cyclizine work?
It is a centrally acting anti-muscarinic and antihistamine
When is cyclizine used?
It is a good first line antiemetic in hospital
Useful for motion sickness and vomiting secondary to raised ICP
What is the dose of cyclizine?
50mg TDS IV/PO/SC
What are some side effects of cyclizine?
Antimuscarinic- dry mouth, constipation
Antihistamine- sedation
What condition should cyclizine be avoided in?
Heart failure
Why should cyclizine and metoclopramide not be prescribed together?
Metoclopramide is a pro-kinetic that treats gastric stasis, due to D2 antagonism.
Cyclizine slows gastric transit due to its antimuscarinic effect.
Therefore block the effects of each other.
What are some metabolic causes of nausea and vomiting?
Renal failure- Uraemia Liver failure Hypercalcaemia Hyponatremia Sepsis