What are the prescribing instructions for Proton Pump Inhibitors (PPIs) compared to famotidine?

From the Guidelines

Proton pump inhibitors (PPIs) should be prescribed with caution in patients taking clopidogrel, and famotidine may be a suitable alternative for patients requiring antiplatelet therapy and acid suppression, as it does not interfere with the metabolism of clopidogrel 1. When prescribing PPIs, it is essential to consider the potential interaction with clopidogrel, as some PPIs, such as omeprazole, lansoprazole, and rabeprazole, may inhibit the metabolism of clopidogrel and reduce its effectiveness 1.

Key Considerations

• PPIs like omeprazole, esomeprazole, pantoprazole, and lansoprazole are typically taken once daily, 30-60 minutes before breakfast for optimal effectiveness.
• The standard adult dose ranges from 20-40mg daily, with treatment duration varying by condition: 4-8 weeks for GERD or ulcers, and potentially longer for maintenance therapy.
• Famotidine (an H2 blocker) can be taken once or twice daily, with or without food, typically at doses of 20-40mg.

Comparison of PPIs and Famotidine

• PPIs irreversibly block acid production by inhibiting the proton pump enzyme system, providing stronger and longer-lasting acid suppression than famotidine, which reversibly blocks histamine receptors on stomach cells.
• Famotidine works more quickly but has a shorter duration than PPIs, making it suitable for as-needed relief.
• The FAMOUS trial found that famotidine 20 mg twice daily reduced the incidence of peptic ulcer or esophagitis in patients taking low-dose aspirin 1.

Clinical Implications

• The use of H2RAs, such as famotidine, can suppress gastric acid production and provide a modest protective effect in patients taking aspirin 1.
• Observational data suggest that PPIs may be more effective than H2RAs in preventing upper GI bleeding in patients with CV disease on antiplatelet therapy 1.
• However, the potential interaction between PPIs and clopidogrel should be considered, and famotidine may be a suitable alternative for patients requiring antiplatelet therapy and acid suppression.

From the Research

Prescribing Instructions for Proton Pump Inhibitors (PPIs) Compared to Famotidine

• PPIs, such as omeprazole, lansoprazole, pantoprazole, and rabeprazole, are prescribed for the treatment of acid-related diseases, including gastroesophageal reflux disease (GERD) and peptic ulcer disease 2.
• The standard dosing regimen for PPIs is once daily, which has been shown to produce endoscopic evidence of healing in >90% of patients with duodenal ulcer after 4 weeks of treatment, in >90% of those with gastric ulcer after 6 weeks of treatment, and in >90% of those with ulcerative or erosive GERD after 8 weeks of treatment 2.
• Famotidine, a histamine-2-receptor antagonist (H2RA), is also used to treat acid-related diseases, but its efficacy and cost-effectiveness have been shown to be inferior to those of PPIs, such as lansoprazole, for the maintenance treatment of reflux esophagitis 3.
• The dosing frequency of PPIs may need to be adjusted in certain patient populations, such as CYP2C19 rapid metabolizers, who may require twice-daily dosing to achieve sufficient acid suppression 4.
• Twice-daily dosing of esomeprazole has been shown to be effective in inhibiting acid secretion in CYP2C19 rapid metabolizers compared to twice-daily omeprazole, lansoprazole, or rabeprazole 4.

Key Differences Between PPIs and Famotidine

• PPIs have a more rapid onset of action and a longer duration of action compared to famotidine 5.
• PPIs are more effective in inhibiting acid secretion and have a lower risk of drug-drug interactions compared to famotidine 5, 3.
• The cost-effectiveness of PPIs, such as lansoprazole, has been shown to be superior to that of famotidine for the maintenance treatment of GERD 3.