ATI RN Pharmacology edition 7.0 (2016)

ATI RN Pharmacology edition 7.0 (2016) A provider prescribes phenobarbital for a client who has a seizure disorder. The medication has a long half-life of 4 days. How many times per day should the nurse expect to administer this medication? A. One B. Two C. Three D. Four - ANSWER A. Medications with long half-lives remain at their therapeutic levels between doses for long periods of time. The nurse should expect to administer this medication once a day. A staff educator is reviewing medication dosages and factors that influence medication metabolism with a group of nurses at an in-service presentation. Which of the following factors should the educator include as a reason to administer lower medication dosages? (Select all that apply.) A. Increased renal secretion B. Increased medication-metabolizing enzymes C. Liver failure D. Peripheral vascular disease E. Concurrent use of medication the same pathway metabolizes - ANSWER Answer: C. Liver failure decreases metabolism and thus increases the concentration of a medication. This requires decreasing the dosage. E. When the same pathway metabolizes two medications, they compete for metabolism, thereby increasing the concentration of one or both medications. This requires decreasing the dosage of one or both medications.