GIT drugs Flashcards
Cimetidine
- H2 antagonist. (-tidine suffix)
- Causes decreased gastric acid secretion in parietal cells.
- Used in heart burn, peptic ulcers…
- Can cause gynecomastia in men and inhibits CYTP450 so can be dangerous.
- Other H2 antagonists - Ranitidine, Femotidine, and Nizatidine.
Ondansetron
- Antiemetic drug, inhibits 5HT-3 receptor.
- Treats vomiting, can cause constipation and headache,
Scopalamine
- Antiemetic drug, muscarinic antagonist.
- Used to treat motion sickness.
Metoclopramid
- Antiemetic drug, D2 antagonist.
- Treats vomiting, and has some upper GI prokinetic effects.
- Can increase prolactin levels.
Aprepitant
- Antiemetic drug, NK1 antagonist.
- Treats vomiting.
- Doesn’t have effects on dopamine, serotonin or muscarinic receptors so has less adverse side effects.
Sodium Bicarbonate
- A systemic antiacid, weak base that is highly soluble and is rapidly absorbed. It reacts and neutralizes gastric acid.
Aluminium Hydroxide
- A non-systemic antiacid, not so soluble and acts only locally in GIT.
- Can lead to constipation!
Magnesium Hydroxide
- A non-systemic antiacid, not so soluble and acts only locally in GIT.
- Can lead to diarrhea!
Misoprostol
- A prostaglandin acting as a protective agent for the gastric mucosa.
Sucralfate
- A mucosal protective agent, acting as a barrier.
- Requires acidic environment to work, so is not combined with antiacids.
Colloidal Bismuth
- A mucosal protective agent, by coating the ulcer protecting it, as well as acting as a bactericidal agent against H. pylori.
- It causes dark feces and black teeth.
Omeprazole + Iansoprazole + Pantoprazole
- Are PPI - Proton pump inhibitors ( -prazole suffix)
- They directly inhibit the proton pumps, and they require an acidic environment to be active.
- They are the 1st line of defense against GERD and duodenal or gastric ulcers.
- Omeprazole is contraindicated in pregnancy!
Bethanechol
- M2 agonist
- Prokinetic agent
Neostigmine
- AChE inhibitor
- Prokinetic agent
Cisaprid
- Excitatory presynaptic 5HT-4 receptor agonist
- Prokinetic agent
Erythromycin
- Excitatory motilin receptor activator
- Prokinetic agent
Magnesium compounds (magnesium hydroxide/ citrate)
- Osmotic laxative
Lactulose
- Osmotic laxative
- Can be also used for hepatic encephalopathy
Polyetheleneglycol
- Osmotic laxative
Psyllium
- Bulk forming laxative
Carboxymethylcellulose
- Bulk forming laxative
Dextrose
- Bulk forming laxative
Plant Gum
- Bulk forming laxative
Decusate Salts
- Stool softeners
Liquid Petroleum
- Lubricant laxative
Senna
- Stimulant laxative
Caster oil
- Stimulant laxative
Cascara
- Stimulant laxative
Bisacodyl
- Stimulant laxative
Phenolphthalein
- Stimulant laxative
Opioids used as antidiarrheals
Loperamide + Diphenoxylate + Opium Tincture
- Decrease bowel motility - feces goes back and forth not allowing it to be excreted.
Octreotide
- A somatostatin analog - Antidiarrheal drug.
- Decreases acid production and decreases intestinal fluid…
- Used to treat symptoms of VIPoma/ carcinoid syndrome/ gastrinoma…
Anticholinergics used as antidiarrheals
Atropine + Belladonna Alkaloids + Hyoscyamine
- They decrease intestinal muscle tone and peristalsis, so slows down movement of feces.
Bismuth Subsalucylate + Kaolin pectin + Activated Charcoal
- These are absorbant antidiarrheal drugs.
- They coat the walls of GIT and bind to the causative agent which is then eliminated.
