Drugs used in nausea and vertigo Flashcards
What drugs can be used in Nausea and vertigo?
anti-emetics
anti-histamines
phenothiazines
Why can phenothiazines be used?
dopamine antagonist - they block the chemoreceptor trigger zone
what is the chemoreceptor trigger zone?
the area in the brain that initiates vomiting so if thats blocked then you wont vomit
What are examples of phenothiazines?
Prochlorperazine
What formulations can phenothiazines come in?
rectal suppositories
buccal tablet
What other drugs can block the chemoreceptor triggering zone?
Haloperidol, domperidone
What is metoclopromide used for?
emesis, vomiting associated with duodenal hepatic ambiliary disease
How does metoclopromide work?
Acts directly in the GI tract
What is the benefit of using domperidone rather than the other medication?
IT has LESS central effects because it doesn’t cross the BBB so therefore less sedation and less dystonic effects
What is the MOA of ondansetron? When is it used?
Blocks the 5HT3 receptors in the GIT and CNS. If the serotonin (5HT3) receptors are blocked it inhibits the vomiting reflex.
Post-operative N/V
When is dexamethasone used?
Cancer-chemotherapy
What and when is Nabilone used?
What are its S/E?
it is a synthetic cannabinoid
used in cytotoxic chemotherapy
Dizziness and drowsiness
When is drug therapy for vomiting used for pregnant patients?
first trimester - vomiting is usually more mild - so drug therapy isn’t necessary
if it is severe they are given the antihistamine promethazine
second line: metoclopromide or prochlorperazine
What factors are considered when giving a patient an antiemetic post-operative surgery?
- Type and duration of surgery
- Anaesthetic used
- Gender? (especially if female)
- Smoker?
- History of PONV
- Intra- and postoperative use of opioids
What other drugs apart of ondansetron are used for post-operative N/V surgery?
Dexamethasone
anti-histamines - such as cyclizine
Two or more can be used in combo as there may be a better response from the patient.
