Patients receiving certain drugs that are metabolized by the CYP3A4 (part of the
ID: 138545 • Letter: P
Question
Patients receiving certain drugs that are metabolized by the CYP3A4 (part of the P450 system) enzyme should not drink grapefruit juice because it inhibits the CYP3A4 enzyme and the drug transporter. The patient asks what might happen if she drinks grapefruit juice and takes the medication. The nurse's response is based on knowledge that the effect could be: a. lack of response to the drug because it does not get close to the site of action. b. possible toxicity because metabolism of the drug is impaired. c. lack of response because the drug will not be absorbed d. liver toxicity because the CYP3A4 enzyme destroys the liver. Smoking induces the CYP1A2 liver enzyme. Warfarin (COUMADIN), and anticoagulant blood thinner, is metabolized by the CYP1A2 enzyme. Because of this interaction, the nurse needs to be alert for what response in the patient receiving warfarin who also smokes tobacco? a. More than expected response to the warfarin. b. Decreased need for the medication warfarin. c. Increased bruising and risk of bleeding. d. Inadequate response to the warfarin. Some oral meds should be taken on an empty stomach; some meds have instructions that state, "don't take with milk or dairy products"; some say "take with OJ, vitamin C; some say take with milk or a meal. Why the differences and how important are these instructions in maintaining consistent drug levels?Explanation / Answer
*) d. Liver toxicity because the CYBP3A4 enzyme destroys the liver.
*) d. Inadequate response to the warfarin.
*) Instructions before medicine administration needed to maintain consistent drug level because,
* Drugs when giving along with some foods result in less response and affect
total perfomance of the drug.( calcium in the milk products affect action of antibiotics)
* Some drugs when given along with other drugs result in antagonistic action.(using
NSAIDS and ACE inhibitors toghether result in antagonistic effect).
* When some drugs administer toghether result in additive action.(using NSAIDS
and Glucocorticoids togheter increase chances of GI bleeding)