تجربة 2 Flashcards
What are the 4 main categories of drugs affecting the GI tract?
1- Antacids
2- Antiemetics
3- Laxatives
4- Anti-diarrheal drugs
How do antacids work to raise gastric pH?
As weak bases, they neutralize acid in the stomach.
What are the common side effects of aluminum hydroxide antacids?
Constipation
How do H2 receptor blockers affect acid production?
They inhibit histamine stimulation of acid production by parietal cells.
Which H2 blocker can inhibit P450 and may lead to drug interactions?
Cimetidine (Tagamet®)
What is the mechanism of action of proton pump inhibitors?
They irreversibly inhibit the H+/K+-ATPase in gastric parietal cells.
Which medication is used to prevent and treat stomach ulcers by stimulating mucus and bicarbonate production?
Misoprostol
What is the role of the ‘vomiting center’ or ‘chemoreceptor trigger zone’ in triggering vomiting?
These areas in the medulla trigger the act of vomiting.
Name a common antiemetic drug that is an H1 antagonist.
Promethazine
What is the primary function of laxatives?
To promote bowel movements by producing soft stools or evacuating the bowel.
How do bulk laxatives like methylcellulose work?
They increase bowel content volume, triggering reflex contractions for peristalsis.
What is the purpose of osmotically active laxatives like magnesium sulfate (Epsom salt)?
To prompt a fluid evacuation of the bowel, typically used in surgeries or poisonings.
What effect do irritant laxatives have on stool?
They cause retention of water through osmosis, leading to softer stool.
What is the active ingredient of Castor oil?
Ricinoleic acid
Which part of Ricinus communis releases Ricinoleic acid?
Oil, through lipase activity
