KPSC Staff Nurse - 2021
Pharmacology
Easy
What is meant by 'trough'?
Appeared in: KPSC Staff Nurse - 2021
Explanation
- The trough level represents the lowest concentration of a drug in the patient's bloodstream.
- It is measured just before the next scheduled dose to ensure the drug level hasn't fallen below a therapeutic level.
- This measurement is crucial for maintaining drug efficacy while preventing toxicity, especially for drugs with a narrow therapeutic range.
Why Other Options Were Wrong
- Option A: This describes the 'time to peak concentration,' which is the duration it takes for a drug to reach its highest level, not the level itself.
- Option C: This is the definition of a 'plateau' or 'steady-state concentration,' which is the stable level achieved after multiple doses, not the lowest point between doses.
- Option D: This defines the 'Minimum Effective Concentration (MEC),' which is the lowest concentration needed for a drug to produce a therapeutic effect. The trough level is a measured value that should ideally remain above the MEC.
Related Visual
Clinical Relevance
- Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacokinetics and Therapeutic Drug Monitoring as background academic context rather than a clinical decision trigger.
- Nurses are responsible for ensuring that blood samples for trough levels are drawn at the correct time (just before the next dose) to ensure accurate results for dose adjustments.
- Monitoring trough levels is critical for drugs with a narrow therapeutic index, such as vancomycin and gentamicin, to prevent serious toxicities like kidney damage (nephrotoxicity) and hearing loss (ototoxicity).
- What if? If a trough level is drawn too early (e.g., several hours before the next dose), the result may be falsely low, potentially leading to an unnecessary and harmful increase in the medication dose.
How to Approach the Question
- Identify the keyword in the question, which is 'trough'.
- Recall the pharmacokinetic definitions related to drug concentration. The word 'trough' itself suggests a low point or valley.
- Evaluate each option based on this understanding. Option A refers to time, not concentration. Option C refers to a stable plateau, not a low point. Option D refers to a threshold for effect, not a measured value between doses.
- Select the option that defines the minimum or lowest concentration of the medication in the blood, which is the correct definition of a trough level.
Concept Tested & Keywords
- Concept Tested: Pharmacokinetics and Therapeutic Drug Monitoring
- Stem keywords: trough, medication
- Lead-in keywords: What is meant by
- Negative lead-in flag: false
Question ID
QZG0DEg6HbNF2Ik5gOltm8
Reference Book
E6 Nursing Fundamentals Potter Perry 12e Part 3 p. 136-138
E6 Robert Boland, Marcia L. Verduin - Kaplan and Sadock's Comprehensive Text of Psychiatry-Wolters Kluwer Health (2024) (pp 1-16525 of 16525) p. 10233-10235
Practise the full KPSC Staff Nurse - 2021
Attempt every question from this paper in a timed mock, then review the full solution for each one.
More General Pharmacology Questions
- Patient with DVT is advised low molecular heparin. At which site nurse will administer this?
- The unpredicted effect of medication in which a client overacts or underacts to a medication is termed:
- A Nursing officer is working in eye ward. A doctor ordered for a specific eye disease an ointment and an eye drops, a prudent nursing officer should…
- You are administering medications to a patient through an intravenous (IV) line. Suddenly, you notice that the IV site is becoming red, swollen, and…
- A physician orders a medication to be administered to a patient in a dose of 200mg twice daily (BD). The pharmacy provides tablets of the medication,…
- Desired dose of Morphine for a patient is 0.4 mg. Dose available is 1 mg/mL. The correct formulation for this patient is:
- What is the precautionary step to be taken before administering an antiserum (or) antitoxin?
- Preferred route of tranexamic acid drug administration is?
- Most common adverse effects of inactivated polio vaccine (IPV)?
- Expected outcome of dopamine is?
More KPSC Staff Nurse - 2021 Questions
- Which of the following forms the myelin sheath in the central nervous system?
- Which cranial nerve innervates the lateral rectus muscle of the eye?
- Which of the following cells secrete pulmonary surfactant?
- Which of the following photoreceptors helps in "bright light vision"?
- Bacilli are the term used for
- As per the psychosocial development theory of Erikson, identity and role confusion are associated with?
- Ability to see beyond outward behavior and sense accurately inner experience of another at a given point is?
- Ivan Pavlov is associated with?
- Perception without stimuli is?
- Behavioral pattern of everyday life which unconsciously arises within a group is?