What is the initial loading (Primary Loading Dose) dose of Intramuscular Injection MgSO4 in Eclampsia?

Appeared in: MP CHO-2018

Explanation

The standard protocol for managing eclampsia, known as the Pritchard regimen, specifies an initial intramuscular (IM) loading dose.
This loading dose consists of a total of 10 g of Magnesium Sulfate (MgSO4).
To ensure proper absorption and minimize local tissue damage and pain, this 10 g dose is divided into two equal parts.
Each part, consisting of 5 g of MgSO4, is injected deep into the upper outer quadrant of each buttock.

Option B: Administering 10 g in each buttock would result in a total dose of 20 g, which is double the recommended loading dose and would lead to severe magnesium toxicity.
Option C: Injecting the full 10 g dose into a single buttock is incorrect. This volume is too large for a single IM site, leading to extreme pain, poor absorption, and increased risk of tissue necrosis.
Option D: A dose of 5 g in a single buttock represents only half of the required total IM loading dose of 10 g. This would be an insufficient dose to effectively prevent further seizures.

Clinical Relevance

Nursing practice connection: Knowing Pharmacological management of eclampsia using Magnesium Sulfate (MgSO4) helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Eclampsia is a life-threatening obstetric emergency. Correct administration of MgSO4 is critical for seizure prevention and maternal safety.
Nurses must be vigilant in monitoring for signs of magnesium toxicity. The disappearance of the patellar reflex is the earliest sign, and if detected, the infusion must be stopped immediately and the physician notified.
The antidote, Calcium Gluconate, must be immediately accessible at the patient's bedside whenever MgSO4 is being administered.

How to Approach the Question

First, identify the key components of the question: 'initial loading dose', 'Intramuscular Injection', 'MgSO4', and 'Eclampsia'.
Recall the standard treatment protocol for eclampsia, which is the Pritchard regimen.
Differentiate between the intravenous (IV) and intramuscular (IM) components of the loading dose.
Remember that the total IM loading dose is 10 g.
Critically evaluate how this total dose is administered. A large 10 g dose is not given in a single site. It is split to ensure safety and efficacy.
Conclude that the 10 g is divided into two 5 g injections, one for each buttock. This leads to the correct option.

Concept Tested & Keywords

Concept Tested: Pharmacological management of eclampsia using Magnesium Sulfate (MgSO4).
Stem keywords: initial loading dose, Intramuscular Injection, MgSO4, Eclampsia
Lead-in keywords: What is

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Attempt every question from this paper in a timed mock, then review the full solution for each one.