Drug class information

Proton Pump Inhibitors (PPIs)

Mechanism of Action (MOA)

• Irreversibly inhibits proton pump; inhibiting the final step of gastric acids production
• PPIs are activated by gastric acids. However, we do not want PPIs to be activated in the lumen of stomach. 
• For PPIs to be work properly, they have to be absorbed in the intestine and gets into the systemic circulation first.
• When PPIs are in the systemic circulation, they will reach to the parietal cells.
• At the parietal cells, PPIs will be activated since there are gastric acids that are not secreted into the lumen of stomach yet. 

• Therefore, the supplications of PPIs are by either enteric-coated (EC) tablet or delayed-release capsule or disintegrating tablet for solution for injection/tube. Some of them are mixed with sodium bicarbonate (as buffering agent). Oral solution is mixed with basic solution. 

Because PPIs have to be systemically absorbed first, they have delayed onset of action (1~2 days)

Because PPIs are irreversibly inhibits proton pump, they have long duration of action (usually QD / BID)

PPIs are more effective than H-2 Antagonists, these drugs can reduce 90% of gastric acid production

Adverse Effects (ADRs) very well tolerated

• Diarrhea 
• Constipation
• Risk of CA-Pneumonia
• Risk of C.Diff Infection
• Osteoporosis (Because of decreased Ca2+ absorption)
• Risk of fractures

Drug-drug Interactions (DDIs)

• Decrease the absorption of drugs that require acidic environment of the stomach

출처: 강의노트