Question

Case study (3)Myocardial Infarction (MI)

Scenario

Mr FG is a 69-year-old retired school teacher who was admitted to the emergencydepartment complaining of severe chest pain after climbing stairs at hisdaughter’s house. In the ambulance he is administered aspirin 300 mg. Onarrival at hospital and subsequent examination and review by the admittingdoctor the following information is obtained.

Previous medical history

Hypertension (10 years). Type 2 diabetes mellitus (recently diagnosed, currentlydiet controlled). The patient is a regular cigarette smoker (>40 per day) anddrinks approximately 10 units of alcohol per week. He has osteoarthritis of theknee.

Family history

Father died following a myocardial infarction at 60 years of age. No maternal

history of cardiovascular disease.

Drug history

Allergies: Trimethoprim. Mr FG has been taking diclofenac MR tablets 75 mg

(twice daily) and nifedipine (Adalat Retard) MR tablets 20 mg (twice daily). Both

were stopped on admission.

Signs and symptoms on examination

▪ Temperature 36.4°C

▪ Blood pressure 160/80 mmHg

▪ Heart rate 75 b/m, regular

▪ Respiratory rate 15 breaths per minute

▪ No basal crackles in the lungs.

▪ An ECG taken immediately on arrival reveals ST elevation of 3 mm in the inferior

▪ leads.

Diagnosis

A preliminary diagnosis of myocardial infarction is made.

Relevant test results

Full blood counts, liver function tests, electrolytes and renal function, CXR,total cholesterol, full blood count and blood glucose were taken at admission.

The following tests taken at admission are reported:

Na+ 134 mmol/L (135–145 mmol/L)

K+ 4.3 mmol/L (3.5–4.0 mmol/L)

Urea 5.2 mmol/L (0–7.5 mmol/L)

Creatinine 81 micromol/L (35–125 micromol/L)

Total cholesterol 5.9 mmol/L (<4 mmol/L)

Blood glucose 4.4 mmol/L (4–10 mmol/L)

Initial treatment

About 45 minutes after the onset of chest pain the patient received the following

treatment in the emergency department:

▪ Heparin 5000 units stat

▪ Reteplase 10 units i.v. bolus followed by a further 10 unit i.v. bolus after 30minutes

▪ Diamorphine 2.5 mg IV stat

▪ Metoclopramide 10 mg stat.

▪ A sliding scale insulin infusion of Actrapid 50 units made up to 50 mL with

sodium chloride 0.9% was initiated and titrated against blood glucose.

The patient is subsequently transferred 2 hours later to the coronary care unit as he is pain-free. As the ward cli

nical pharmacist, you are responsible for dailyreview of drug charts and advice to medical and nursing staff on all aspects ofdrug treatment for patients on the ward.

1.What further diagnostic and biochemical tests should be ordered to help confirm the diagnosis?

2. What is myocardial infarction and what are the classic symptoms?

3. Explain the mechanism of action of thrombolytics such as reteplase in acute MI?

4. The physician order Beta-blockers, Statins, ACE inhibitors, Antiplatelet therapy as standard secondary prevention treatment following acute myocardial infarction in this patient?For each of the classifications give an example of drug name, indication, action, adverse effect, and how can you minimize the adverse effect?

5. Mr FG experiences a chest infection 4 days post admission and is prescribedamoxicillin 500 mg three times daily and erythromycin 500 mg four times daily.What problems may this cause with this patient’s statin therapy and what advicewould you give in order to avoid this problem occurring? (Drug interaction)

6. What effect may occur if this client has decreased renal function and the physician order to give him digoxin? What actions could be taken to minimize this effect?

7. What advice should be given to the patient at discharge with regard to lifestyle

issues?

Answer 1

Q1.

The diagnostic test that can be done to diagnosed are echocardiogram, angiogram, ECG, and the biochemical test that can be done are creatine kinase - MB , troponin test.

Q2.

Answer. Myocardial infarction is defined as an emergency situation that occur due to blockage of coronary arteries leads to lack of oxygen in the tissue of the heart.

The symptoms includes

• Tightness and squeezing pain in the chest radiating to neck, jaw, back
• Shortness of breat
• Fatique
• Sudden dizziness

Q3.

answer. Reteplase combine with the plasminogen to produce plasmin. This plasmin help in fibrinolysis of blood clot to maintain normal blood flow in the body. This leads to elimination of blood clot and prevent the blockage of the coranary arteries and increase oxygen supply in the heart tissues.

Q4.

Answer.

	Drug name	Indication	Action	adverse effect	minimize adverse effect
Beta- blocker	atenolol	Hypertension	it block the action of epinephrine in the heart leads to reduce the blood pressure, heart rate.	Dizziness Headache Tiredness Nausea. Allergic reaction	Observe for 30 minutes after the administration for any side effect. Take the medication with proper dose and frequency Check the blood pressure before taking the drug.
Statin	atrovastatin	to lower cholesterol level - stroke - heart attack	It slow down the production of cholesterol in the body and reduce the build up of cholesterol in the blood vessel wall	- muscle pain - weakness - dark urine - kidney problem - nausea and vomiting	- take after advice by doctor - take proper dose - limit alcohol intake
ACE inhibitor	Benazepril	- hypertension	it bind and inhibits ACE and block the conversion of angiotensin I to angitensin II	- muscle weakness - nausea - vomiting - chest pain - swelling of the body part	- check the expiry date - take the medication same dose and frequency - educate the patient regarding the drug
Antiplatelet therapy	clopidogrel	- thromboembolism - ischemic heart disease	It inhibit the platelet activation and makes blood more thinner.	- bleeding - nausea Vomiting - diarrhea - nose bleeding	- check the platelet level, bleeding time and caogulation time before administering it.