Famotidine
- Class: H2 blocker
- Used for: heartburn
- Say it: fuh-MOH-tih-deen
- Forms: tablet, oral liquid, injection
Remember the name – FAM → famine
FAMOTIDINE brings a FAMINE to the acid-making cells — less is made, so less burns.
Blocking the H2 receptor removes histamine's signal to secrete. A famine, not a shutdown: the pump still answers to its other signals, which is why a PPI goes further.
FAMOTIDINE brings a FAMINE to the acid-making cells — less is made, so less burns.
Blocking the H2 receptor removes histamine's signal to secrete. A famine, not a shutdown: the pump still answers to its other signals, which is why a PPI goes further.
Mnemonic: A -TIDINE turns the tap down
H2 blockers end in -tidine. They block one of the switches that turn the acid pump on, so they act faster than a PPI but never as completely.
H2 blockers end in -tidine. They block one of the switches that turn the acid pump on, so they act faster than a PPI but never as completely.
Side effects
Common: headache, constipation, dizziness
Serious: confusion in older adults
Typical dose
20–40 mg once or twice daily
Reduce the dose in renal impairment.
Check yourself
How does Famotidine differ from omeprazole?
- It blocks the histamine signal that switches the pump on, rather than the pump itself
- It blocks the acid pump directly
- It neutralises acid that is already in the stomach
- It forms a protective coat over the ulcer
Show answer
A. It blocks the histamine signal that switches the pump on, rather than the pump itself
Histamine is only one of several signals that activate the pump, so blocking it leaves other routes open. That is why an H2 blocker is weaker than a PPI, which shuts the final common step.
See it, don't memorize it
The app has the mechanism comic and a patient case for Famotidine – plus the name link, the class mnemonic, pronunciation you can hear, and a self-check, for the top 100 drugs. One purchase, no subscription, no account.