The effect of single dose triamterene lasts for how many hours?

Appeared in: RRB Nsg. Superintendent -29 April-2025 (shift-2nd)

Explanation

Triamterene is classified as a short-acting potassium-sparing diuretic.
According to pharmacology references, the duration of action for an oral dose of triamterene is approximately 7 to 9 hours.
Among the given choices, the 6-8 hour range is the most accurate representation of its clinical effect duration.
Its relatively short half-life (2-3 hours) contributes to this limited duration of action.

Option A: A duration of 12-16 hours is too long for triamterene. This range is more characteristic of some thiazide diuretics.
Option B: A duration of 18-20 hours is incorrect. This describes a long-acting diuretic, which triamterene is not.
Option C: A duration greater than 20 hours is characteristic of long-acting diuretics, such as spironolactone (another potassium-sparing diuretic) which can act for 2-3 days, or amiloride which can act for up to 24 hours.

Visual 1: Chart: Comparison of Diuretic Classes - A visual chart showing the onset, peak, and duration of action for loop, thiazide, and potassium-sparing diuretics to help differentiate them.
Visual 2: Diagram: Nephron Action Sites - An illustration of a nephron showing where each class of diuretic exerts its effect (e.g., triamterene in the distal tubule and collecting ducts).

Clinical Relevance

Nursing practice connection: Knowing Pharmacokinetics of Diuretics helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Knowing the duration of action helps the nurse schedule medication administration to maximize therapeutic effects while minimizing side effects like nocturia. Triamterene is best given in the morning.
The primary safety concern with triamterene is hyperkalemia. The nurse must educate the patient to avoid potassium-rich salt substitutes and supplements and monitor potassium levels, especially when co-administered with ACE inhibitors.
The short duration of action explains why it might be prescribed twice daily to maintain its diuretic and potassium-sparing effects throughout the day.

How to Approach the Question

First, identify the drug mentioned in the question: Triamterene.
Recall the pharmacological class of Triamterene, which is a potassium-sparing diuretic.
Access your knowledge about the pharmacokinetics (onset, peak, duration) of this specific drug class and drug.
Remember that Triamterene is a relatively short-acting diuretic compared to others in its class like spironolactone.
Compare the known duration of action (around 7-9 hours) with the options provided.
Select the option that best matches this timeframe, which is 6-8 hours.

Concept Tested & Keywords

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