Intramuscular Famotidine Administration

Evidence and Dosing

The American Society of Anesthesiologists guidelines acknowledge that intramuscular famotidine is effective in reducing gastric volume and acidity during the perioperative period, based on placebo-controlled randomized controlled trial evidence, representing Category A3-B evidence, indicating moderate-quality data supporting its efficacy 1
20 mg intramuscularly is the established dose based on clinical trial data 1
This dose provides acid suppression lasting approximately 6 hours 2

In perioperative settings where oral administration is not feasible due to NPO status, intramuscular famotidine may be considered 1
Patients unable to take oral or IV medications may also benefit from intramuscular famotidine 1
In critical care settings where stress ulcer prophylaxis is needed, though IV or enteral routes are preferred, intramuscular famotidine can be an option 3
Oral and IV routes are more commonly used than IM administration 3
For stress ulcer prophylaxis in critically ill adults, low-dose famotidine (≤40 mg daily) is recommended regardless of route 3
The enteral route is generally preferred when the GI tract is functional 3

Tachyphylaxis can develop within 6 weeks of initiating H2 receptor antagonist therapy, requiring periodic assessment of continued need for therapy 4
Famotidine does not interfere with clopidogrel's antiplatelet activity, making it preferable to proton pump inhibitors in patients on dual antiplatelet therapy 5