Slide 18 of 76
Notes:
1) Medications are often recommended to be taken with food for one of two reasons:
a) To ensure optimal absorption.
- e.g., Nelfinavir is best absorbed if it is taken with a meal or snack.
- In some instances, fat content of a meal may be an important factor affecting drug bioavailability. With lipid-soluble agents, ingestion of dietary fat results in formation of an oil or emulsion phase, with subsequent improvement in solubility. Ingesting a fatty meal also promotes secretion of gastric fluids, which in turn may lower gastric pH, delay stomach emptying, and decrease gastrointestinal transit rates. The absorption of saquinavir is significantly increased when taken within 2 hours of a high-fat meal.
- b) To reduce side effects involving the stomach.
- Some agents, such as ritonavir or zidovudine do not necessarily need to be taken with food for adequate absorption. However, the presence of food may often prevent or minimize the risk of stomach upset or nausea. This, in turn, may reduce the chance of non-adherence due to drug side effects.
2) Empty stomach requirements:
- Certain medications may be sensitive to the conditions in the stomach. For example, indinavir is better absorbed on an empty stomach. High protein and fat-containing foods can significantly lower the amount of indinavir that gets into the body. Therefore indinavir should always be taken on an empty stomach or with a light, low-fat snack
- Didanosine (ddI) is another drug that needs special conditions in the stomach to be absorbed properly. It is destroyed by stomach acid, and therefore the didanosine tablets contain an antacid buffer. Didanosine should always be taken on an empty stomach, since the presence of food might interfere with the action of the buffers.
3) 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 together with antacids or didanosine.
