Gi Pharmacology Flashcards
Give the name of some proton pump inhibitors
Mechanism, use, toxicity of proton pump inhibitors
Omeprazole lansoprazole
Irreversibly inhibits H+/K+ ATPase @Parietal cells
For peptic ulcers, gastritis, oesophageal reflux, Zollinger Ellison syndrome
Toxicities = increased risk of C. difficile, pneumonia, decreased serum Mg2+
Give the name of someone H2-blockers
Mechanism?
Clinical use?
Toxicity?
Cimetidine ranitidine famotidine nizatidine
Peptic ulcer, gastritis, mild oesophageal reflux
CCCCimetidine = CCAp
inhibit CCCCytochrome p 450
Cross blood-brain barrier + cross placenta
Antiandrogenic = prolactin release, impotence, gynaecomastia, decreased libido
CCCimetidine + RRRanitidine =
Decrease CCCreatinine RRRenal excretion
What is the mechanism of business and sucralfate and what is its clinical use ?
Binds to also base = physical protection
Allowed bicarb secretion ->
re-establish pH gradient @mucus layer
For ulcer healing + Travellers diarrhoea
What is Misoprostol?
Mechanism?
Use?
Toxicity?
Prostaglandin E1 analogue =
produce & secrete gastric mucus barrier
+
decrease acid production
Use = prevent NSAID induced peptic ulcer Slimed maintain PDA
Induced labour by ripening cervix
Toxicity = diarrhoea
Give the name of a long acting somatostatin analogues
Mechanism? Use? Toxicity?
Octreotide
Inhibit action of splanchnic vasoconstriction hormones
Carcinoid tumours, Acute variceal bleed, VIPoma, Acromegaly
Toxicity = nausea cramps steatorrhea
How do antacids affect other drugs?
Problems with aluminium hydroxide calcium carbonate and magnesium hydroxide
Affect absorption bioavailability and urine excretion
Aluminium hydroxide =
constipation hypophosphataemia, osteodystrophy, proximal muscle weakness, seizures
Calcium carbonate = hypocalcaemia
Magnesium hydroxide =
cardiac arrest, hypo reflex/tension, diarrhoea
Types of osmotic laxatives?
Mechanism?
Use?
Toxicity?
Provide osmotic load – >draw water into GI Newman
Use = constipation Lactulose = for hepatic encephalopathy: Lactulose breakdown by good flora -> Lactic acid + acetic acid – > promotes N excretion = NH4+
Toxicity = diarrhoea and dehydration
Mechanism of sulphasalazine
Use?
Toxicity?
Sulphasalazine = sulfapyrifine (antibacterial) \+ 5 aminosalicylic acid (any anti-inflammatory) -> activated by colonic bacteria
Use = ulcerative colitis and crohns
Toxicity cause malaise nausea oligospermia
Ondansetron mechanism use toxicity?
Five HT three antagonist = decrease vagal stimulation = central acting antiemetic
Used to control vomiting post operatively + chemo
Toxicity =
constipation
headache
increased Q-T interval
Mechanism use and toxicity of orlistat?
Inhibits gastric + pancreatic lipase – >
decrease breakdown + decreased absorption of fats
Use equals weight loss
Toxicity =
steatorrhea +
decreased absorption of fat-soluble vitamins
Mechanism of metoclopramide
Use? Toxicity?
D2 receptor antagonist
Increased motility, resting town, contractility, oesophageal sphincter tone
use = antiemetic + gastroparesis (diabetic + post surgery)
Toxicity = Parkinsonian effect, restless, drowsy, fatigue, depressed, diarrhoea, tardive dyskinesia
Contraindications = don’t take with the DIGOXIN or if have small-bowel obstruction/Parkinson’s disease
What is infliximab What is this use and toxicity?
Monoclonal antibody to TNF alpha
Use = crohns ulcerative colitis rheumatoid arthritis ankylosing spondylitis psoriasis
Toxicity = infection Fever hypotension
Patients is sick after a car ride is alsosick due to some sort of stomach irritant is also pregnant what drugs can you give Her?
Histamine one antagonists = Cinnarizine cyclizine promethazine
Also give ACh M receptor antagonist = hyoscine
gets dry mouth and learning as well
If a patient is on fluorouracil etoposide methotrexate vinca Alkaloids or abdominal radiotherapy what symptom of a likely to suffer from? What severity Is the emetogenicity?
Nausea and vomiting
Mildly emetogenic give dopamine antagonist
Is a patient on taxanes doxorubicin Cyclophophamide mitoxantrane methotrexate what symptom is the patient likely to suffer from? What severity Is the emetogenicity?
Nausea and vomiting
Moderately emetogenic give dexamethasone/Lorazepam
If a patient is on cisplatin dacarbazine and Cyclophophamide made what symptoms the patient likely to suffer from? What severity Is the emetogenicity?
Nausea and vomiting
Highly emetogenic give 5HT3 antagonist or neurokinin antagonist
Patient has chronic constipation What drug can you give?
5 HT for agonist prucalopride = 5 HT stimulates ACh release + myenteric plexus
What is iopromide/Imodium used for ?
Decreases abdominal cramps + slow faeces passage – > for diarrhoea
Patient has spasming due to IBS + diverticuli disease what can you give them and what side-effects would you get ?
Muscarinic antagonists
Side effects = drymouthed blurry vision
