Introduction
The pharmacy sector is a growing industry globally. For an internationally trained pharmacist who wishes to become a registered pharmacist in Australia, it’s very important to know about the complete procedure. The first step in the whole process in understanding everything about the licensure exam in Australia for international pharmacy graduates. The Overseas Pharmacists Readiness Assessment (OPRA) exam is introduced in March 2025 by replacing KAPS Exam. The OPRA Exam is conducted by the Australian Pharmacy Council (APC).
Core topics like pharmacology are highly evaluated in these types of competitive exams. Drugs for Diabetes are widely discussed in the pharma field. Metformin is one of the most popular drugs prescribed for Type 2 Diabetes Mellitus. It is questioned in the OPRA exam. Students who are preparing for this exam should understand its mechanism of action, pharmacology, and clinical significance is essential for pharmacists aiming to work in Australia.
This guide simplifies how metformin works explained in OPRA-style clarity for pharmacy students.
Overview of Metformin
| Category | Details |
| Drug Class | Biguanide |
| Primary Use | Used as a first line treatment for diabetic patients |
| Mechanism | Reduces hepatic glucose production and increases insulin sensitivity |
Mechanism of Action — Step by Step
It will reduce the production of hepatic Glucose
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The primary mechanism of action of metformin is to inhibit the gluconeogenesis in the liver.
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There is an enzyme known as AMP-activated protein kinase (AMPK). It activates the reduction of glucose synthesis and enhances insulin sensitivity.
Improves the peripheral Glucose Uptake
- It will improve the sensitivity to insulin within muscle and adipose tissue
- Increases GLUT-4 translocation, promoting glucose uptake into cells.
Delays Intestinal Glucose Absorption
- It will reduce the glucose absorption in the GI tract, It will help to lower the after-food blood glucose levels.
Improves Lipid Profile
- It will reduce the cholesterol level, especially triglycerides and LDL cholesterol.
- It also improves the HDL levels
Pharmacokinetics
| Property | Description |
| Absorption | Incomplete; peak levels in 2–3 hour |
| Distribution | Not protein-bound |
| Metabolism | Not metabolized |
| Excretion | Renally excreted unchanged |
| Half-life | ~6 hours |
OPRA Tip: Metformin’s renal clearance is crucial — always monitor serum creatinine and eGFR before initiating therapy.
Clinical Uses
- Used as a first line treatment for diabetic patient
- It can improve the body’s response to insulin in PCOD patients
- It can improve the insulin resistance in patients who shows to become diabetic
- It’s rarely prescribed to manage weight. Its not clinically accepted or proven
Adverse Effects
| Common | Serious (Rare) |
| Nausea, diarrhea, metallic taste | Lactic acidosis (especially in renal/hepatic impairment) |
Drug Interactions
- Cimetidine → Increases metformin levels
- Contrast agents → Risk of lactic acidosis
- Alcohol → Potentiates hypoglycemia and acidosis
OPRA Exam Pointers
- Focus on AMPK activation mechanism
- Remember no hypoglycemia when used alone
- Know the contraindications (renal, hepatic, cardiac failure)
- Understand pharmacokinetics – no metabolism, renal excretion
Summary Table
| Key Concept | Quick Revision Point |
| Mechanism | Activates AMPK, inhibits gluconeogenesis |
| Hypoglycemia Risk | No (unless combined with insulin/sulfonylurea) |
| Main Adverse Effect | GI upset |
| Severe Adverse Effect | Lactic acidosis |
| Excretion | Unchanged in urine |
| OPRA Tip | Focus on hepatic and cellular effects |
Why OPRA Aspirants Must Master This Topic
The OPRA Exam 2025 is the first step for overseas-trained pharmacists who wish to work in Australia. This exam focuses on clinical knowledge, patient care, and ethical decision-making, it ensures that international students meet the highest quality of pharmacy practice.Metformin is among the most frequently tested drugs in OPRA pharmacology papers.
Conclusion: Prepare with Elite Expertise
Elite Expertise offers comprehensive OPRA coaching programs covering pharmacology, clinical case studies, and mock exams tailored for 2025.
Our modules simplify tough concepts like metformin’s action, insulin pathways, and drug interactions with visual aids and interactive sessions — helping you build confidence for the OPRA exam.
At Elite Expertise, we comprehensively cover these rare yet critical conditions in our OPRA coaching. Our trainers, Mr Arief Mohammad and Mrs Harika Bheemavarpu, are accredited clinical consultants in Australia who bring real-life clinical experience into every virtual class. Their case-based teaching approach helps students understand not only the theory but also its practical, real-world application, ensuring they are exam-ready and confident in practising pharmacy in Australia.
Join Elite Expertise today and take the next step toward becoming a licensed pharmacist in Australia.
Frequently asked questions:
- What is the main action of metformin?
It reduces hepatic glucose production via AMPK activation. - Does metformin cause hypoglycemia?
Not when used alone. - What organ eliminates metformin?
It is excreted unchanged by the kidneys. - What enzyme does metformin activate?
AMP-activated protein kinase (AMPK). - What is the most common side effect?
Gastrointestinal discomfort. - Can metformin be used in renal failure?
No, it’s contraindicated when eGFR < 30. - Does metformin affect weight?
It may promote mild weight loss. - What is a serious adverse effect?
Lactic acidosis (rare). - Is metformin metabolized in the liver?
No, it’s not metabolized. - Why is it important for OPRA exam prep?
It’s a frequently tested pharmacology topic in OPRA papers.
