Module 4 - Case Study

Questions 1

The dose and frequency of administration you would use?

One of the factors that affect the dosage of Glyceryl trinitrate is the type of infusion made use of. Dose recommendation symbolized as glyceryl trinitrate mcg/min can only be given as a starting rate of infusion. Some of the major factors to consider before administering the drug to Leonard include assessing him for presence of circulatory disorders such as acute circulatory failure, hypotension and cardiogenic shock among others. Assessing the medical history of the patient will help determine whether Leonard has myocardial infarction, a condition under which glyceryl trinitrate should only be made use of strictly by the treating doctors. Consumption of other drugs should also be considered in determining the dosage and frequency of administering glyceryl trinitrate. Leonard is concerned which implies that the current dosage needs to be either down-regulated or increased in accordance with his therapeutic response. The frequency of administration also needs to be regulated under the guidance of current dosage of Glycerine trinitrate to minimize possible cases of overdose or underdose.

The patient’s vital signs and history you consider important?

Presence of medical history of cardiovascular disorders is important in the determination of dosage and frequency of administration of Glycerine trinitrate. The vital signs of the patient will help determine whether current medications are generating any positive results or not. Mr. Leonard is taking other drugs most of which have been shown to develop adverse side effects.

Monitoring of vital signs will therefore assist in determining the dosage of Glycerine trinitrate to start with.

Questions 2

1. pharmacodynamic rationale for administering this drug

Based on the fact that glyceryl trinitrate is used in the management of heart disorders, it would be expected of the drug to reduce the stress and pressure exerted on cardiac muscles by a variety of factors including reduced myocardial flow of blood.

2. The mechanism of action of GTN. Glyceryl trinitrate has been shown to posses the capacity to relax smooth muscles. Relaxation of smooth muscles results in reduction of systolic pressure. Anti-angina effects of Glyceryl trinitrate are dependent on its ability to reduce myocardial demand of oxygen. This drug results in peripheral vasodilation, an aspect which leads to decreased venous return. Consequently, energy expenditure in the left ventricle reduces significantly thereby reducing the workload for heat muscles (Aronson 2009).

3. The pharmacokinetic rationale for the sublingual route of administration of Glyceryl trinitrate has an efficient rate of oral absorption. The drug is also readily metabolized. Absorption of the drug in the gastrointestinal tract is also high. However, bioavailability of the drug is minimal due to its high first pass effect. Bioavailability of the drug is about 1% following administration through the mouth (Aronson 2009).

4. Any specific instructions or advice you would give to Leonard regarding the use of this medication

I would advice Leonard on the possibility of development of a severe headache following administration of this drug. I would also advise Leonard to take minimal doses of this drug to reduce cases of methaemoglobinaemia from occurring.

Question 4

1. What is your clinical reasoning for giving Leonard aspirin at this stage?

The pharmacodynamic rationale for administering aspirin in this setting

Aspirin can be administered at this stage to reduce pain and associated inflammation. Aspirin also minimizes the risk of death by inhibiting cases of blood clotting.

3. The mechanism of action of aspirin relevant to this setting

Aspirin mainly works through blocking the action of cyclooxygenase. Obstruction of cyclooxygenase production minimizes production of prostaglandin, the chemical that triggers pain.

4. Anything you would consider before giving Leonard this drug and the reasons for these

Considerations

It is however, important to determine whether Leonard is allergic to aspirin, since development of an allergy at this stage would aggravate an already worse medical condition.

5. The advice you would give Leonard about the drug and the way in which it is administered.

Some of the advice I would give Leonard concerning this drug is that he should never take it before being prescribed by a doctor. It is also advisable to keep doses for this drug as minimal as possible to reduce cases of aspirin overdose. Lower doses also minimize the risk of internal bleeding

Question 5

1. What is the rational for administering clopidogrel to Leonard?

Clopidogrel is an extremely effective drug in the management of ischemic heart disease. It prevents the formation of clots in persons who have in the recent past had a heart attack. This drug is administered to Leonard based on the fact that he has poor circulation of blood.

2. The pharmacodynamic rationale for administering clopidogrel

It is expected that after administration of clopidogrel the flow of blood to heart muscles and other parts of the body will be enhanced. It is also expected that possibility of clots formation will be eliminated.

3. The mechanism of action of clopidogrel

Clopidogrel functions though inhibiting certain subtypes of ADP receptor that pays a key role in the activation of platelets. Clopidogrel functions mainly through inhibition of platelet aggregation.

4. What are the implications of administering clopidogrel prior to coronary angiography? Even though clopidogrel is a highly effective drug, its administration may result in hemorrhage in the digestive tract. The drug can also increase the risk of cerebral hemorrhage (Khan 2005).

5. In what clinical situation would it be inappropriate to administer clopidogrel to Leonard?

It would be inappropriate to administer clopidogrel in situations whereby the patient is taking other drugs such as omeprazole since concomitant administration may result in adverse effects. The drugs should also not be administered if the patient is presenting with extremely minimal levels of white blood cells.