Absorption, drug food effects

Tab. 21.6. Potential food effects on drug absorption for BCS class I—III drugs.

Investigation of potential food effects on drug absorption. 

Investigation of Potential Food Effects on Drug Absorption... 

Drug/Food interactions Vitamin K-rich vegetables may decrease the anticoagulant effects of warfarin by interfering with absorption. Minimize consumption of vitamin K-rich foods (eg, spinach, seaweed, broccoli, turnip greens) or nutritional supplements. Mango has been shown to increase warfarin s effect. 

Drug/Food interactions Absorption of glipizide is delayed by approximately 40 minutes when taken with food the drug is more effective when given approximately 30 minutes before a meal. The other sulfonylureas may be taken with food. 

Drug/Food interactions Food enhances the bioavailability of metoprolol and propranolol this effect is not noted with nadolol, bisoprolol, or pindolol. The rate of carteolol and penbutolol absorption is slowed by the presence of food however, extent of absorption is not appreciably affected. Sotalol absorption is reduced approximately 20% by a standard meal. 

Drug/Food interactions Theophylline elimination is increased (half-life shortened) by a low carbohydrate, high protein diet, and charcoal broiled beef (due to a high polycyclic carbon content). Conversely, elimination is decreased (prolonged half-life) by a high carbohydrate low protein diet. Food may alter the bioavailability and absorption pattern of certain sustained-release preparations. Some sustained-release preparations may be subject to rapid release of their contents when taken with food, resulting in toxicity. It appears that consistent administration in the fasting state allows predictability of effects. 

Food effect, absorption of most psychotropic drugs is not significantly affected by concomitant intake of food. An exception is buspirone, with a twofold increase of absorption with food intake... 

Food-Effect Studies. Coadministration of food with oral drug products may influence drug BA and/or BE. Food-effect BA studies focus on the effects of food on the release of the drug substance from the drug product as well as the absorption of the drug substance. BE studies with food focus on demonstrating comparable BA between test and reference products when coadministered with meals. Usually, a single-dose, two-period, two-treatment, two-sequence crossover study is recommended for both food-effect BA and BE studies. 

Factors affecting drug absorption include formulation, disease state, food effect, and drug-drug interaction. Formulations used for oral administration include solutions, suspensions, capsules, and uncoated and coated tablets. Depending on the formulation of a drug, the absorption characteristics may differ substantially. 

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