Interstinal Mobility, Secretion, Nausea And Vomiting (related Drugs Too) Flashcards
What might nausea be attributed too?
- anxiety
- motion sickness
- migraine
- pregnancy
- side effects of drugs
Why do we vomit and where in the CNS is it triggered?
- defence mechanism
- vomiting/emetic centre located in the brain stem
What are the categories of Anti-Emetic drugs (treat vomiting/nausea)
- antihistamine (H1 receptor antagonits)
- antimuscarinics (muscarinic acetylcholine receptor anatagonists)
- 5-HT3 receptor antagonists
- dompamine receptor antagonists
- neurokinin-1 receptor antagonists
What drugs are antihistamines?
- cyclizine
- promethazine
- diphenydramine
What drug is antimuscarinics (muscarinic acetylcholine receptor antagonists)?
- scopolamine (hyoscine)
What drugs are 5-HT3 receptor antagonists?
- onadansetron
- granisetron
- palonosetron
What drugs are dopamine receptor antagonists?
- chlorpromazine
- droperidol
- haloperidol
- prochlorperazine
- metoclopramide
What drugs are neuron in in-1 receptor antagonists?
- fosaprepitant
- aprepitant
Antihistamines:
What is the primary action? Indication for use? And side effects?
- act primarily as antagonists at histamine H1 receptors in the brain
- indication for use: nausea and vomiting -> motion sickness
- side effects: sedation (because they act at H1 receptors in the brain which regulate the sleep-wake cycle, arousal, cognition, and memory)
Antimuscarinics:
What is the primary action? Indication for use? And side effects?
- act primarily as antagonists at muscarinic acetylcholine M1 receptors in the brain
- indicated use: Motion sickness
- side effects: antimuscarinics side-effects such as dry mouth, tachycardia and constipation
5-HT3 receptor antagonists:
What is the primary action? Indication for use? And side effects?
- act primarily as antagonists at 5-HT3 receptors in the chemoreceptor trigger zone of the medulla in the hind brain and also the 5-HT3 receptors in the gastrointestinal tract
- indication of use: treat nausea and vomiting (mainly before and after chemotherapy??)
- side-effects: constipation, diarrhoea and headache
Dopamine receptor antagonists:
What is the primary action? Indication for use? And side effects?
- act primarily as antagonists at D2 receptors in the chemoreceptor trigger zone of the medulla in the hindbrain (except domperidone) and also the D2 receptors in the gastrointestinal tract
- indications of use: nausea or psychosis
- side-effects: diarrhoea, extrapyramidal side effects (except domperidone)
Neurokinin-1 receptor antagonists:
What is the primary action? Indication for use? And side effects?
- act primarily as antagonists at NK1 receptors in the GI tract and the chemoreceptor trigger zone of the medulla in the midbrain blocking the effects of substance P (which evokes vomiting)
Indications of use: postsurgical nausea and vomiting and cancer chemotherapy-induced nausea and vomiting - side-effects: constipation and headache
What drugs affect gastrointestinal motility?
- antidiarrhoel drugs
- loperamide, diphenoxylate
- drugs that reduce constipation
- naloxegol
- prucalopride
- lubiprostone
- laxatives
- bulk laxatives
- osmotic laxatives
- stimulant laxatives
- Faecal softeners
- docusate sodium
Diarrhoea treatment (anti-diarrhoea drugs)
- electrolyte replacement
- loperamide and diphenoxylate are opiates (bind to u-opiate receptors) that has reduced effect on brain
- sometimes combined with atropine (muscarinic acetylcholine receptor antagonist)
- high doses of loperamide have been associated with drug abuse
- side effects: constipation, sedation, respiratory depression (common for opiates)
