NUR 557 Module 4 Case Paper Example

Many Defects, Two Drugs: Joining the Pathophysiology of Type 2 Diabetes to Metformin and Empagliflozin

[Student Name]

Southern New Hampshire University

NUR 557: Advanced Pathophysiology and Pharmacology Across the Lifespan

Case Paper

[Instructor Name]

[Date]

The organization, setting and figures below are a composite written as a model document. No real employer, client, colleague or patient is described.

Many Defects, Two Drugs: Joining the Pathophysiology of Type 2 Diabetes to Metformin and Empagliflozin

Type 2 diabetes is not one defect but several, and each drug class corrects only some of them. That makes it a clear example of why pharmacology should be learned through pathophysiology. This paper explains the diabetes of a composite 55-year-old man and joins his two medicines to the defects they target. It argues that metformin and empagliflozin are a logical pair for him because they act on different organs, the liver and the kidney, and that his previous heart attack makes empagliflozin a priority for its cardiovascular benefit, not only for its effect on glucose.

The Case

The patient is a 55-year-old warehouse supervisor with a body mass index of 34 who had a heart attack two years ago and has taken aspirin, a statin and a beta-blocker since. A routine test showed an A1C of 8.1%, confirmed on repeat. He has mild thirst but no other symptoms. His estimated glomerular filtration rate is 78 and his blood pressure is 138/84 mm Hg. He has had two genital yeast infections in the past, both easily treated.

The Defects Behind His Glucose

DeFronzo (2009) described type 2 diabetes as the product of several abnormalities acting together. In muscle, insulin resistance means that insulin drives less glucose into cells after meals. In the liver, resistance means insulin fails to suppress glucose production, so the liver keeps releasing glucose overnight and between meals, the main source of a high fasting glucose. Fat tissue resistant to insulin releases excess free fatty acids, which worsen resistance in muscle and liver. Pancreatic alpha cells release too much glucagon, which also drives the liver. Beta cells compensate at first by making more insulin, but their function declines, and diabetes appears when they can no longer keep up. The kidneys add to the problem: they reclaim almost all filtered glucose through the SGLT2 transporter in the proximal tubule, and in diabetes that capacity increases, holding glucose in the blood.

His obesity, particularly abdominal fat, is the most likely driver of his insulin resistance, and his rising A1C reflects beta cells that can no longer compensate.

Placing the Drugs on the Defects

Current standards recommend metformin as first-line therapy for most people with type 2 diabetes and, for those with established atherosclerotic cardiovascular disease, a drug from one of the two classes with proven heart benefit, an SGLT2 inhibitor or a GLP-1 agonist, independent of the A1C (American Diabetes Association Professional Practice Committee, 2025). Table 1 shows where each of his drugs acts.

Table 1

Where Each Drug Acts and What It Predicts

Metformin's main action is on the liver, where it reduces glucose production; the exact molecular mechanism remains debated but involves effects on mitochondrial energy metabolism in liver cells (Rosenthal & Burchum, 2021). Because it does not stimulate insulin release, it rarely causes hypoglycemia on its own. Its gastrointestinal effects are dose-related, which is why it is started low and taken with food.

Empagliflozin works at a site no other defect-correcting drug reaches. By blocking SGLT2, it lets the kidney excrete excess glucose and sodium. Its benefits extend beyond glucose. In the EMPA-REG OUTCOME trial, which enrolled adults who already had both diabetes and heart or vascular disease, empagliflozin reduced cardiovascular death by 38% relative to placebo and reduced hospitalization for heart failure (Zinman et al., 2015). The mechanism of that benefit is thought to involve sodium loss, lower blood pressure and changes in cardiac and kidney physiology rather than glucose alone. For this patient, that is the reason to start it now.

Predicting and Preventing Adverse Effects

The mechanism of empagliflozin predicts its main side effects. Glucose in the urine feeds yeast, so genital infections are more common, and his history makes this likely; he should be taught hygiene measures and told what to watch for. The loss of sodium and water can cause dizziness, especially when combined with other blood pressure medicines or during illness, so he should hold the drug on days he cannot eat or drink and during acute illness, which also lowers the rare risk of ketoacidosis with near-normal glucose. Metformin's effect on B12 absorption makes periodic B12 checks sensible over years of use, particularly if tingling in the feet develops.

What the Patient Should Notice

Explaining the mechanisms to the patient helps him recognize what the drugs are doing. Within a week or two of starting empagliflozin he may notice more frequent urination, which is the drug working, and a slight drop in weight over months as calories leave in the urine. Metformin may loosen his stools at first; taking it with his largest meal and increasing the dose slowly usually settles this. Neither drug should cause shaky, sweaty episodes of low blood sugar on its own, so if they occur, something else is going on and he should call. His beta-blocker could blunt some warning signs, which is another reason to choose drugs that rarely cause hypoglycemia. Over three months, the goal is an A1C closer to target, a small fall in blood pressure and no new cardiac events.

Age and Organ Function

At 55 with good kidney function, he needs no dose adjustments, but both drugs depend on the kidneys in different ways. Metformin is eliminated unchanged by the kidneys and must be reduced or stopped as filtration falls to low levels because of the rare risk of lactic acidosis. Empagliflozin's glucose-lowering effect weakens as filtration declines, since less glucose is filtered, but its heart and kidney benefits persist at lower levels of kidney function (American Diabetes Association Professional Practice Committee, 2025). Kidney function should therefore be checked at least yearly, and the plan revisited if it changes.

Conclusion

This patient's diabetes reflects insulin resistance, failing beta cells, an overactive liver and kidneys that reclaim too much glucose. Metformin corrects the liver's excess output with little risk of hypoglycemia, and empagliflozin lets the kidneys shed excess glucose while lowering his risk of cardiovascular death and heart failure, the reason it belongs in his plan from the start. The same mechanisms predict their side effects and the monitoring each needs: yeast infections and sick-day rules for one, stomach upset and vitamin B12 for the other, and kidney function for both.

References

American Diabetes Association Professional Practice Committee. (2025). 9. Pharmacologic approaches to glycemic treatment: Standards of care in diabetes 2025. Diabetes Care, 48(Suppl. 1), S181-S206. https://doi.org/10.2337/dc25-S009

DeFronzo, R. A. (2009). From the triumvirate to the ominous octet: A new paradigm for the treatment of type 2 diabetes mellitus. Diabetes, 58(4), 773-795. https://doi.org/10.2337/db09-9028

Rosenthal, L. D., & Burchum, J. R. (2021). Lehne's pharmacotherapeutics for advanced practice nurses and physician associates (2nd ed.). Elsevier.

Zinman, B., Wanner, C., Lachin, J. M., Fitchett, D., Bluhmki, E., Hantel, S., Mattheus, M., Devins, T., Johansen, O. E., Woerle, H. J., Broedl, U. C., & Inzucchi, S. E. (2015). Empagliflozin, cardiovascular outcomes, and mortality in type 2 diabetes. New England Journal of Medicine, 373(22), 2117-2128. https://doi.org/10.1056/NEJMoa1504720