Flashcards in Pharm2 4 GI Drugs pt2 Deck (20)
What are they used for? (3)
Competitive antagonist at muscarinic acetylcholine (M1) receptors
Used for the prophylaxis and/or treatment of nausea and motion sickness, intestinal cramping
What is the antiemetic patch put on behind the ear?
Scoplolamine transdermal is indicated for postop N/V, but nobody uses it for this anymore.
How is it used now?
Put it on 12-24 hours before you do the activity that will cause the motion sickness.
Take it off before putting on another, and put the other one behind the other ear.
Scoplolamine Transdermal (Transderm Scop®)
angle-closure (narrow angle) glaucoma
also if fhey are hypersensitive to any ingredients in it (scopolamine, belladonna alkaloids)
Caution in pregnancy
Dec secretion of saliva (dry mouth), sweat,
Dec gastrointestinal secretions, motility, cause drowsiness, dilates pupils,
Dec heart rate
warned of the possibility and cautioned against engaging in activities that require mental alertness, such as driving a motor vehicle or operating dangerous machinery (blender, hairdryer, other normal things around the house)
The adverse effects of __ are similar to some street drugs: ketamine, bath salts, mushrooms,
rarely, idiosyncratic reactions may occur with ordinary therapeutic doses of scopolamine, the most serious of these that have been reported are: acute psychosis, confusion, agitation, rambling speech, hallucinations, paranoid behaviors, and delusions.
Dopamine Receptor Antagonists
What is their primary use?
Antagonist activity at domamine D2 receptors in the chemoreceptor trigger zone (CTZ) within the brain.
Blockade dec N/V triggered by most stimuli
At higher doses, 5-HT3 antagonist activity may also inc anti-emetic effect
Primarily used to N/V, and to facilitate gastric empying in patients with gastroparesis
ex of Dopamine Receptor Antagonist
What does it mainly do?
Inc preistalsis of the jejunum & duodenum
Inc tone and amplitude of gastric contractions, and relaxes pyloric sphincter.
___ is used almost exclusively in diabetics with gastroparesis.
Contraindications: pheochromocytoma, Parkinson’s disease, suspected bowel obstruction.
Pregnancy: Cat. A
Side effects: restlessness, drowsiness, dizziness, lassitude, and/or dystonic reactions
*What is almost the exclusive use of Metclopramide?
Used almost exclusively to treat gastroparesis in diabetics
What is the gold standard to control nausea/vomiting produced by cancer chemotherapy
5-HT3 RAs (one type of anti-emetic)
When are they particularly effective?
dec activity of the vagus nerve, which activates the vomiting center in the medulla oblongata
Particularly effective in controlling N/V produced by cancer chemotherapy, and are considered the gold standard for this purpose
5-HT receptor is also for ___. (besides nausea, vomiting)
migraines are more frequent in women because they have more receptors in their medulla as well as in their gut, to give them the nausea.
Example, route of admin
When is it used? To treat N/V from: (3)
Ondansetron (PO dissolving tablet, IV, IM)
Tx/prevent N/V from chemotherapy, post op, acute gastroenteritis.
Side effects of Ordansetron (rare)
well-tolerated drug with few side effects; constipation, dizziness and headache are most common (but still rare)
Substance P/Neurokinin-1 RAs
Blocks signals given off by neurokinin 1 (NK1) receptors decrease likelihood of a patient experiencing N/V with chemotherapy
ex of Substance P/NK1 RA
What's it used for?
It is almost always used in combo with __, and frequently used with __.
*This class is phenomenal for a chemotherapeutic patient.
It is almost always used in combination with 5-HT3 RAs (i.e., ondansetron) and frequently with dexamethasone
Contraindications: allergy to drug or class
Pregnancy: Cat. B
Side effects: well-tolerated drug with few side effects
Adverse Events: rare