Week 11 - H2 Receptor Antagonists Flashcards
Which drugs are histamine type 2 receptor antagonists?
- Famotidine (Pepcid)
- Cimetidine (Tagamet)
Describe the mechanism of action of the histamine type 2 receptor antagonists
When histamine type 2 receptors are stimulated they increase the production of stomach acid by gastric parietal cells - H2RAs competitively block these receptors
True or false:
H2RAs increase the tone of the lower esophageal sphincter
True
The absorption of cimeditine and famotidine is ____________ by food
unaffected
The presence of ________ requires cautious use of the H2RAs and dosage adjustments.
renal impairment
What are the side effects associated with H2RAs?
- antiandrogenic effects (gynecomastia, impotence)
- CNS effects (confusion/disorientation, agitation)
- Drowsiness/dizziness
Cimetidine has a greater degree of effects than famotidine
The drug interactions associated with H2RAs are related to what aspect of their metabolism?
CYP450
Which H2RA has the greatest concern for drug-drug interactions?
What are some notable drug interactions?
Cimetidine
* benzos
* CCBs
* BBs
* warfarin
The H2RAs are most effective when used as ____________
on-demand therapy for relief of GERD symptoms
Because many people develop ____________ H2RAs are not used as first-line continuous therapy for GERD
tachyphylaxis
Decreased response to the drug
H2RAs should be taken ________ meals and at bedtime to achieve the best effects.
with
When taking _________, it is important to instruct patients to take the drug as prescribed for the full course of therapy, even if they are feeling better.
H2RA’s
PPI
