Question

1. Discuss the consequences of drug–drug interactions, the basic mechanisms of drug–drug interactions, and the critical steps in minimizing adverse drug–drug interactions.
2. Focus on the liver as an example of a drug-metabolizing system and explain why it is such a crucial organ in many drug–drug interactions.
3. Discuss the effect of food on drug absorption, on drug metabolism (e.g., grapefruit juice), and on drug toxicity and action, as well as the timing of drug administration with respect to meals.
4. Give examples of inhibitory interaction of drugs that can produce dangerous effects and those that are beneficial.
5. Discuss the mechanisms and clinical consequences of drug–herb interactions and drug–food interactions. Focus on ways to minimize adverse drug–drug interactions and drug–food interactions. Include in the discussion the effect of food on drug absorption and metabolism, drug toxicity, drug action, and the timing of drug administration with respect to meals.
6. Discuss the dilemma that increased consumption of herbal supplements has created in the pharmaceutical environment because of these supplements’ potential for common and significant interactions with prescription and over-the-counter drugs.
7. Design a plan of care for patients who are prescribed medications that have known drug–drug or drug–food interactions.
8. Identify electronic resources available for determining action, side effects, therapeutic index, and anticipated effects of drugs.

Answer 1

Answer: Drug interaction may be defined as a interaction between two drugs or drug to food which may increase or decrease the effectiveness of the drug or may cause major side effects. There are two kinds of interaction:

Drug- drug interactions: In this kind of interaction, when the two drugs taken simultaneously or together interacts with eachother to increase or decrease the bioavailability of any of the drug. Sometimes some of the medicines are taken together to increase the effectiveness where as some of the drug decreases the other positive act of drug. Digoxin and Quinidine if taken together it may give rise to conditions such as serious nausea and vomiting which can be fatal.

The drug taken orally is metabolize in the liver, the enzymes present in the liver cells protects the accumulation of the drug i.e. lipid soluble compounds by converting them into water soluble and hence it gets excreted by kidney. But sometimes when a large amount of drugs gets accumulated in the liver, it causes liver toxicity.

Most of the drugs are taken along with the food to increase the GI absorption whereas some of the medicines should not be taken along with some of the foods such as grape juice etc.

Drug food interactions: This interaction occurs when the food interfere in the functioning of the drug, which may increase or decrease the drug absorption. Example , calcium tablet should not be taken with milk as it forms complex and hence no absorption takes place.

Mostly drug should be administered as directed by the pharmacist as well as physician. Drug should be taken after 15-20 minutes of the meal. This reduces the chances of the drug interactions.

The drug herb interaction occurs such as ginseng reduces the effectiveness of the antidepressants. Some of the herbs elevate the performance of the drug.