Gastric pH Interactions
Drugs that need acidic pH:
- Indinavir
- Delavirdine (50% ? in alkaline pH)
Take with acidic beverage if achlorhydric
Caution with:
- H2-blockers, proton pump inhibitors
- antacids, ddI tablets
Notes:
- Certain medications are sensitive to gastric pH. For instance, optimal absorption of agents such as indinavir, delavirdine, ketoconazole and itraconazole occurs in an acidic gastric environment
- However, advanced HIV patients may experience achlorhydria, which may adversely affect drug bioavailability. Thus, if achlorhydria is suspected, administration of an acidic beverage, such as Coca-ColaTM may be recommended.
- In addition, patients should avoid taking these drugs at the same time as antacids or didanosine. For instance, although indinavir and didanosine both need to be taken on an empty stomach, they cannot be administered together because of their opposite gastric pH requirements. Doses should be spaced at least 1 hour apart.