Analgesics And Anti-emetics Flashcards
(21 cards)
What are the pharmacological targets for anti-emetic drugs?
Histamine receptors (H1)
Serotonin receptors (5HT3)
Muscarinic receptors (M)
Dopamine receptors (D2)
Substance P/Neurokinin (NK1)
Which part of the brain controls the vomiting reflex?
The medulla oblongata
Name three drugs that are histamine receptor antagonists and their primary uses
Cyclazine -motion sickness
Cinnarizine -motion sickness, vestibular disorders (eg. Vertigo)
Promethazine -severe morning sickness
How do hisamine receptor agonists work?
By activating H-receptors on the blood vessels in the inner ear, causing local vasodilation, increased permeability and reversal of the underlying problem of endolymphatic hydrops
Give an example of a hisamine receptor agonist
Betahistine hydrochloride
Name two muscarinic receptor antagonists and what they are mainly used for
Hyoscine
Scopolamine
Motion sickness and general purpose anti-emesis
What are the side effects of muscarinic receptor antagonists?
Dry mouth
Blurred vision
Which part of the vomiting reflex do dopamine receptor antagonists work on, and therefore what types of sickness do they prevent?
The chemoreceptor trigger zone:
GI disorders
Viral gastroenteritis
Opioid induced emesis
Uraemia
Name three dopamine receptor antagonists
Phenothiazines
Perphenazine
Prochloropromazibe
Metoclopramide
Domperidone
Name the serotonin receptor antagonists and the types of emesis they are used against
Ondansetron
Granisetron
Palonosetron
Tropisetron
Used for chemotherapy, anaesthetic and radiation induced emesis
When are neurokinin-1 (substance P) receptor antagonists used?
In late phase emesis with cytotoxic drugs: chemotherapy induced and anaesthetic induced emesis
Name two NK1 receptor antagonists
Aprepitant
Fosaprepitant
Casopitant
Maropitant
What are the side effects associated with substance P antagonists?
Fatigue
Listlessness
Constipation or diarrhoea
Loss of appetite
Hiccups
Dizziness
Tinnitus
Headache
What are the different classes of analgesics?
Opioids
Antidepressants
Antiepileptics
Local anaesthetics
How do opioids work in pain relief?
By acting at the level of the spinal cord to decrease neurotransmitter release and block postsynaptic receptors
and in the brain stem by activating inhibitory pathways (the body’s own suppression of pain)
What are the side effects associated with opioids?
Nausea
Vomiting
Constipation
Drowsiness
Respiratory depression
Hypotension
Sedation
Dependency
How do serotonin and noradrenaline reputable inhibitors (SNRI) and selective serotonin reputable inhibitors (SSRI) work to reduce pain?
By preventing the recycling of neurotransmitters, which increases the action of the ascending pain pathways in the brain
How do antiepileptic drugs work to reduce pain?
They inhibit voltage-gated Na+ and Ca2+ channels to inhibit action potential firing and to prevent impulse transmission
Enhance neuronal inhibition
Which antiepileptic drugs are used for analgesia?
Carbamazepine
Gabapentin
Both used for neuralgia and neuropathic pain
How do local anaesthetics work?
By inhibiting voltage-gated Na+ channels or NMDA receptors, which inhibits nerve firing and impulse transmission
Which drugs are local anaesthetics?
Lidocaine
Ketamine
