Dose of levonorgestrel to be given as emergency contraceptive?

AIIMS CRE SNO - 2023

Pharmacology

Easy

Appeared in: AIIMS CRE SNO - 2023

Explanation

The standard and most common regimen for levonorgestrel as an emergency contraceptive is a single 1.5 mg oral dose.
This dose is proven to be effective in preventing pregnancy when taken as soon as possible after unprotected intercourse, ideally within 72 hours, but can be used up to 120 hours.
An older regimen involved two 0.75 mg doses taken 12 hours apart, which also totals 1.5 mg, but the single-dose method is preferred for better compliance.

Option B: This option uses the incorrect unit. A microgram (mcg) is 1,000 times smaller than a milligram (mg). A dose of 1.5 mcg would be sub-therapeutic and completely ineffective for contraception.
Option C: A 3 mg dose is incorrect and is double the recommended single dose for levonorgestrel emergency contraception. Such a high dose is not standard and could increase the risk of side effects without improving efficacy.
Option D: This option has both an incorrect numerical value (3) and an incorrect unit (mcg). This dose is clinically insignificant and would have no contraceptive effect.

Visual 1: Image: Packaging of an over-the-counter levonorgestrel 1.5 mg emergency contraceptive pill (e.g., Plan B One-Step, i-Pill) to help visualize the product and its labeling.
Visual 2: Flowchart: Timeline for Emergency Contraception, showing the effectiveness windows for Levonorgestrel (most effective within 72 hours) and Ulipristal Acetate (up to 120 hours).

Clinical Relevance

Nursing practice connection: Prioritize focused assessment, early escalation, and real-time monitoring when managing Pharmacology: Emergency Contraception Dosage in acute care settings.
Nurses must counsel patients on the critical importance of taking the correct dose as soon as possible after unprotected sex, ideally within 72 hours, for maximum efficacy.
Patient education should include common side effects like nausea, vomiting, and changes in the next menstrual cycle, and emphasize that it does not protect against sexually transmitted infections (STIs).
What if the patient vomits within 2 hours of taking the pill? The nurse should advise the patient to contact a healthcare provider, as a repeat dose is often necessary to ensure effectiveness.

How to Approach the Question

This is a factual recall question testing knowledge of a specific drug dosage, a common topic in nursing exams.
First, identify the key components of the question: the drug (levonorgestrel) and its specific use (emergency contraceptive).
Pay extremely close attention to both the numerical value and the unit of measurement (mg vs. mcg). Test-makers often use incorrect units as distractors.
Recall the standard single-dose regimen for this common medication. The most frequent dose is 1.5 mg.
Systematically eliminate the other options. Options with 'mcg' are highly likely to be incorrect for this type of oral medication. The 3 mg option is double the standard dose and also incorrect.

Concept Tested & Keywords

Concept Tested: Pharmacology: Emergency Contraception Dosage
Stem keywords: levonorgestrel, emergency contraceptive, dose
Lead-in keywords: BEST, MOST RELEVANT CLUE
Clinical cues: The care setting changes urgency, monitoring level, and the expected nursing action.
Negative lead-in flag: false

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