Antiemetics Flashcards
True or false, cyclizine is a D2 antagonist used to treat motion sickness
False
True or false, aprepitant is a substance P agonist which has anti-emetic properties
False
Dexamethasone may be used in combination with D2 or 5HT3 antagonists to treat CINV, true or false
True
Ondansetron is considered the drug if choice for CINV, true or false
True
Which of the following chemicals act on the chemoreceptor trigger zone; Acetylcholine Serotonin Bradykinin Dopamine
Acetylcholine
Serotonin
Dopamine
Cyclizine, cinnarizine and promethazine are what type of anti emetic
Histamine H1 receptor antagonists
What type of antiemetic is ondansetron
Serotonin receptor antagonist
What type of antiemetic is hycosine and scopolamine
Muscarinic receptor antagonist
What type of antiemetics are phenothiazines, chloropromazine and perphenazine?
D2 receptor antagonists
What type of antiemetic is nabilone
Cannabinoid
What type of antiemetic is aprepitant
Neurokinin-1 antagonist
What percentage of cancer patients treated with anti-neoplastic agents experience emesis?
70-80%
Which clinically used drugs are often associated with high levels of emesis
Anti cancer agents
Anaesthetics
Opioids
The vomiting reflex is regulated by which part of the CNS
Medulla
Where is the chemoreceptor trigger zone located
Dorsal Vagal complex
Which pathway inputs into the dorsal Vagal complex causes nausea and vomiting in pregnancy
The Vagal pathway
Which pathway inputs into the dorsal Vagal complex causes nausea and vomiting from motion/height
The vestibular pathway
Where is the main site of action of antiemetic drugs
Chemoreceptor trigger zone
Which emesis pathway is linked to sensory input, stimuli from the pharynx and stimuli from the GI tract
Vagal pathway
True of false, antiemetics are agonists
False, they are antagonists
Antiemetic H1 antagonists inhibit the release of what substance
Histamine
Antiemetic H1 antagonists work less well where?
A. Chemoreceptor trigger zone
B. Vagal pathway
C. Vestibular pathway
Chemoreceptor trigger zone
Which H1 antagonists could be given for motion sickness?
A. Cyclizine
B. Cinnarizine
C. Promethazine
Cyclizine and cinnarizine
What are the side effects of antiemetic H1 antagonists?
Drowsiness and sedation
What is the drug of choice for severe morning sickness in pregnancy
A. Cinnarizine
B. Cyclizine
C. Promethazine
Promethazine
When you the antiemetic H1 antagonist cinnarizine be prescribed
Motion sickness
Vestibular disorders
When would you use the H3 receptor agonist betahistine hydrochloride?
Vertigo
Which antiemetics are good “general purpose” antiemetics
Muscarinic Rs antagonists; hyoscine, scopolaimine
True or false, hyoscine, scopolamine is the drug of choice for motion sickness
True
How are the antiemetics Muscarinic Rs antagonists hyoscine/scopolamine administered
Oral and/or transdermal patch
Where do antiemetic D2 receptor antagonists work strongly
Chemoreceptor trigger zone
True or false, antiemetic D2 Rs antagonists have a powerful antiemetic action and will antagonise Muscarinic and histamine receptors too
True
Phenothiazines, metoclopramide and domperidone are all examples of what type of antiemetic
D2 Rs antagonist
Perphenazine, prochloropramazine and phenothiazines are examples of which antiemetic
D2 Rs antagonist
Which D2 Rs antagonist antiemetic is indicated for severe morning sickness of pregnancy A. Domperidone B. Metoclopramide C. Trifluoperazine D. Phenothiazines
Phenothiazines
How is the D2 Rs antagonist antiemetic phenothiazines administered
Orally
IV
Suppository
Which D2 Rs antagonist anti emetic penetrates the blood-brain barrier
Metoclopramide
How is the drug metoclopramide administered
Oral
IV/IM
Which D2 Rs antagonist anti emetic is used for migraine and cytotoxic therapy-induced emesis and emesis due to emergency hormonal contraception
Domperidone
Does the antiemetic domperidone penetrate the blood brain barrier?
No
True or false, D2 Rs antagonists have an effect on chemoreceptor trigger zone, Vagal pathway and the vestibular pathway
False, they do not effect the vestibular pathway
What type of antiemetic is ondansetron, granisetron, palonosetron and tropisetron?
5HT3 antagonist
What is the drug if choice for chemotherapy induced nausea and vomiting (CINV) and postoperative nausea and vomiting (PONV)
Ondansetron
How can the antiemetic ondansetron be administered
Oral
Suppositories
IV
IM
What are the side effects of the antiemetic ondansetron
Gastrointestinal disturbances
Headache
Which two types of antiemetics work on the vestibular pathway?
Muscarinic Rs antagonists
H1 Rs antagonists
Which 3 antiemetics work on the Vagal pathway?
5HT3 antagonists
D2 Rs antagonists
H1 Rs antagonists
Which 3 types of antiemetics work on the chemoreceptor trigger zone
5HT3 antagonists
D2 Rs antagonists
M antagonists
The antiemetic aprepitant is an antagonist of what?
Substance P NK1R
What is active in late phase emesis with cytotoxic drugs?
Neurokinin 1 (substance P)
What is the substance P antagonist used for
CINV
PONV
What is the route of administration of aprepitant
Oral
IV
Fosaprepitant is a pro drug of what antiemetic
Aprepitant
Casopitant, maropritant, aprepitant and Fosaprepitant are all examples of what kind of anti emetic?
Neurokinin 1 (substance P) antagonists
The antiemetics nabilone and marinol are examples of what
Cannabinoids
Antiemetic cannabinoids mimetic the main chemical componant of cannibis - which is?
HTC
Which antiemetic is used adjunct to chronic pain management
Nabilone - cannabinoid
How is it thought the antiemetic nabilone works?
Act via opioid receptors in the chemoreceptor trigger zone
Corticosteroids such as Dexamethasone can be used for what kind of emesis
Vomiting caused by cytotoxics
Dexamethasone is used in combination with which 2 other antiemetics to improve their actions
D2 and 5HT3 antagonists
Which drugs would you use for anticipatory emesis?
Benzodiazepines
Which two antiemetics are most suitable for emesis causes by opioids?
Haloperidol
Metoclopramide
Which antiemetic is most suitable for emesis caused by gastroenteritis
Metoclopramide
Apomorphine is what kind of drug?
Emetic
How is the emetic apomorphine administered?
IM
Subcut
How long does it take for the emetic apomorphine to act
5-10mins
Which is the most commonly used emetic?
A. Ipecacuanha
B. Apomorphine
C. Activated charcoal
Activated charcoal
