Nokea
The student nurse asks the instructor why a patient with a central nervous system infection is receiving antibiotics that will not cross the blood-brain barrier. What is the instructor's most correct response?
- A. A severe infection alters the blood-brain barrier to allow the drug to cross.
- B. A medication that is water soluble is more likely to cross the blood-brain barrier.
- C. Antibiotics are the exception to the blood-brain barrier and cross easily.
- D. An infection that spreads outside the central nervous system helps drugs cross the barrier.
Correct Answer: A
Rationale: Effective antibiotic treatment can occur only when the infection is severe enough to alter the blood-brain barrier and allow antibiotics to cross. Lipid-soluble, not water-soluble, medications cross the blood-brain barrier more easily and most antibiotics are lipid soluble, so they are not the exception. No matter where the infection originates, drugs must cross the blood-brain barrier to treat central nervous system infections.
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A nurse working in radiology administers iodine to a patient who is having a computed tomography (CT) scan. The nurse working on the oncology unit administers chemotherapy to patients who have cancer. At the Public Health Department, a nurse administers a measles-mumps-rubella (MMR) vaccine to a 14-month-old child as a routine immunization. Which branch of pharmacology best describes the actions of all three nurses?
- A. Pharmacoeconomics
- B. Pharmacotherapeutics
- C. Pharmacodynamics
- D. Pharmacokinetics
Correct Answer: B
Rationale: Pharmacology is the study of the biologic effects of chemicals. Nurses are involved with clinical pharmacology or pharmacotherapeutics, which is a branch of pharmacology that deals with the uses of drugs to treat, prevent, and diagnose disease. The radiology nurse is administering a drug to help diagnose a disease. The oncology nurse is administering a drug to help treat a disease. Pharmacoeconomics includes any costs involved in drug therapy. Pharmacodynamics involves how a drug affects the body and pharmacokinetics is how the body acts on the body.
All of the following are adverse effects of phenothiazines except
- A. Rigidity and tremor
- B. Menstrual irregularities
- C. Cholestatic jaundice
- D. Systolic hypertension
Correct Answer: D
Rationale: Phenothiazines cause hypotension, not hypertension.
The following drug causes a decrease in aqueous humour secretions from the ciliary body:
- A. Propranolol
- B. Nadolol
- C. Carvedilol
- D. Timolol
Correct Answer: D
Rationale: Timolol, a beta-blocker, reduces aqueous humor production in glaucoma.
The reason that two MMR vaccines at least a month apart are recommended is:
- A. The second dose of MMR 'boosts' the immunity built from the first dose
- B. Two vaccines 1 month apart is the standard dosing for all live virus vaccines
- C. If the two MMR vaccine doses are given too close together there is a greater likelihood of severe localized reaction to the vaccine
- D. Only 95% of patients are fully immunized for measles after the first vaccine, with 99% having immunity after two doses of MMR
Correct Answer: D
Rationale: Two MMR doses ensure 99% immunity, as 95% respond to one dose; boosting is secondary to this goal.
Which of the following is the indication for glucocorticoid prescribing?
- A. Cataract
- B. Prevention of respiratory distress
- C. Hypofunction of thyroid gland
- D. Hypocalcemia
Correct Answer: B
Rationale: Glucocorticoids are indicated to prevent respiratory distress, such as in preterm infants for lung maturation.