Gastro Drugs Flashcards
What is a potential side effect of systemic antacid use?
Metabolic alkalosis
What type of drugs are Neurokinin1 (NK-1) receptor antagonists?
Anti-emetics
What does H1 receptor antagonists treat?
Motion sickness
Hay fever
Nausea and Vomiting
How do bulking agents work?
They absorb water > increase in size > stimulates movement
How does hyoscine butylbromide act as a anti-diarrhoeal?
Muscarinic receptor antagonists therefore decrease gut motility
What is misoprostol?
A synthetic prostaglandin E2 analogue
What effect do cannabinoids have?
Anti-emetic
What is the problem with lipid paraffin?
Takes vitamins with it
Leaks out of the anus
Can cause pneumonia is aspirated
What is hyoscine hydrobromide?
A muscarinic receptor antagonist used for motion sickness
What drugs are used for nausea associated with migraine?
Metoclopramide
Chlorpromazine
How long is it advisible to stay on proton pump inhibitors for ulcers to heal?
8 weeks
Metoclopramide has another effect apart from being a anti-emetic, what is it?
Increase stomach and upper small intestine motility
What type of drug is Esomeprazole?
Proton pump inhibitor
What drugs target the chemoreceptor trigger zone?
Dopamine D2 receptor antagonists - Metoclopramide and Prochlorperazine
How does metoclopradine increase gut motility
Block dopamine’s inhibition of ACh release (being a dopamine D2 receptor antagonists)
Agonist of 5HT4 receptor > increase ACh release
Note: ACh acts on gastric smooth muscle to increase motility
Name a Serotonin 5HT3-Receptor Antagonists
Ondansetron
What are Ranitidine and Cimetidine?
H2 receptor antagonists
What type of drug is Hyoscine butylbromide?
Spasmolytic
At what point do extrapyramidal side effects of certain anti-emetic drugs become irreversible?
When tardic dyskinesia develops
Parkinson’s like symptoms or extrapyramadial side effects are cause by which class of drugs?
Dopamine D2 antagonists
What are Serotonin 5HT3-Receptor Antagonists used for?
Extremely potent anti-emetics
How does Rantidine work?
It is a H2 receptor antagonist
It blocks histamine stimulation of acid secretion in parietal cells
What are the side effects of H2 receptor antagonists?
No major side effects in current ones
Cimetidine causes gynecomastia in males
What are some causes of constipation?
Drugs (esp opioids)
Inadequate dietary fibre/water
Inadequate exercise
Spinal injury
Ignoring the “call” to go
Bowel cancer
Depression
Which opioid is used as an anti-diarrhoeal? Why?
Loperamide
Doesn’t cross the BBB therefore doesn’t cause the CNS effects
Which class of drug was classically thought to danger the colon with long term however has recently been found not to?
Irritant laxatives
What type of drug is liquid paraffin?
Oil lubricant
What are the most used laxative currently?
Irritant laxatives
What is the main side effect of Promethazine and other drugs of its class?
Sedation
What are H2 receptor antagonists indicated for?
Gastric ulcers
Name a bulking agent
Brann