Pharmacodynamics, pharmacokinetics, pharmacogenetics

Question 1

What is the simple definition of Pharmacokinetics

Answer 1

What your body does to the drug - i.e ADME (absorption, distribution, metabolism, and excretion)

Question 2

What is the simple definition of Pharmacodynamics

Answer 2

What the drug does to your body - i.e at the cellular level what effect is this drug having

Question 3

What does ADME stand for?

Answer 3

A - Absorption
D - Distribution
M - Metabolism
E - Excretion

Question 4

What is absorption?

Answer 4

How the drug is moved from the site of administration through to your blood

Question 5

What is Distribution?

Answer 5

How the body takes the drug from the blood to your tissues

Question 6

What is metabolism?

Answer 6

How the body converts the drug into other forms

Question 7

What is Excretion?

Answer 7

How the converted form of the drug is excreted from the body - Either via the kidneys, stool, bile or sweat or even exhaled fluid.

Question 8

What is the first-pass metabolism?

Answer 8

When a drug is metabolised at a specific location in the body (often the liver) resulting in a reduced concentration of the active drug reaction the site of action/systemic circulation

Question 9

What is bioavailability?

Answer 9

Bioavailability refers to the fraction or percentage of a drug that reaches the systemic circulation after administration and is available to exert its pharmacological effect. In other words, bioavailability is a measure of the amount of a drug that is absorbed and becomes available at the site of action.

Question 10

What factors can cause a drug to have less than 100% bioavailability?

Answer 10

Several factors can affect the bioavailability of a drug, including the route of administration, the solubility and stability of the drug, the presence of food or other drugs in the gastrointestinal tract, the first-pass metabolism by the liver, and the rate of absorption and distribution of the drug into the bloodstream.

Question 11

Why would a patient require a higher dose of oral Morphine than intravenous for effective analgesia

Answer 11

As oral dosages have less bioavailability thus a higher dose is required to produce the required effect.

“The reason why a patient may require a higher dose of oral morphine than intravenous for effective analgesia is due to differences in bioavailability. Oral administration of morphine is subject to extensive first-pass metabolism by the liver, which can significantly reduce the bioavailability of the drug. In contrast, intravenous administration bypasses the first-pass metabolism and delivers the drug directly into the systemic circulation, resulting in a higher bioavailability and more potent effect. Therefore, to achieve the same level of analgesia, a higher dose of oral morphine may be required compared to intravenous administration”

Question 12

What are some of the factors that influence distribution of a drug?

Answer 12

The distribution of a drug in the body can be influenced by factors such as the physiochemical properties of the drug, blood flow, protein binding, membrane permeability, metabolism, disease states, and genetics. Understanding these factors can help healthcare professionals optimize drug distribution and ensure medications are effective and safe.

Question 13

What is the most important plasma protein produced?

Answer 13

Albumin

Question 14

Why is the plasma protein albumin important?

Answer 14

Because its good at binding to certain drugs within blood.

Question 15

What is a loading dose?

Answer 15

an initial higher dose of a drug that may be given at the beginning of a course of treatment, so that a steady state (theraputic window) is reached more quickly then smaller ‘maintenance’ doses are given to ensure that the drug levels stay within the steady state

Question 16

What is specificity?

Answer 16

Specificity is the measure of a receptors ability to respond to a single ligand

Question 17

What are agonists?

Answer 17

Drugs that interact with receptors and produce a response

Question 18

What are antagonist?

Answer 18

Drugs that interact with receptors as to block the action of agonists or the naturally occurring chemical messenger

Question 19

What is polymorphism?

Answer 19

a genetic variation in the DNA sequence that leads to differences in an individual’s physical traits or biological functions, including drug metabolism. Polymorphisms can affect drug absorption, distribution, metabolism, and excretion, as well as drug interactions and adverse drug reactions.

Question 20

Which enzymes are responsible for most of drug metabolism?

Answer 20

cytochrome p450 (CYPs) which are found in the liver and other tissues.

Question 21

What is pharmacogenetics?

Answer 21

Pharmacogenetics is the study of how an individual’s genetic makeup affects their response to medications. It involves genetic testing, analysis of genetic data, clinical decision-making, and monitoring and adjusting treatment. By understanding an individual’s genetic profile, doctors can tailor medication regimens to optimise their effectiveness and reduce the risk of adverse reactions.

Question 22

Where are receptors commonly found

Answer 22

On the cell membrane

Question 23

What is pharmacology?

Answer 23

The study of drugs and their actions in the body.

Question 24

What are the different types of drugs?

Answer 24

Prescription drugs, over-the-counter drugs, and complementary medicines.

Question 25

What are complementary medicines?

Answer 25

medicines and practices used in addition to or instead of conventional medical treatments, such as herbal remedies, vitamins and dietary supplements, acupuncture, meditation, and massage therapy.

Question 26

What are drug receptors?

Answer 26

Sites on cells where drugs can bind and produce their effects

Question 27

What factors effect drug absorption?

Answer 27

Route of administration, dosage, drug formulation, and patient factors (age, health status ect)

Question 28

What are some common routes of drug administration?

Answer 28

Oral, topical, inhalation, injection, and transdermal.

Question 29

Why is it important for healthcare professionals to have a good understanding of pharmacology?

Answer 29

So that they can administer medications safely and effectively, and monitor patients for adverse effects.

Question 30

What are some key considerations when administering medications to patients.

Answer 30

Consider the dosage, route, patient education, adverse effects, and documentation.

Question 31

What factors influence the rate of gastrointestinal absorption?

Answer 31

The rate of gastrointestinal absorption of drugs can be influenced by several factors, including the solubility of the drug, the pH of the stomach and intestines, the presence of food in the stomach, the surface area of absorption in the intestines, and the blood flow to the gastrointestinal tract.

Question 32

Why do the effects of a drug administered sublingually occur rapidly?

Answer 32

The effects of sublingual administration occur rapidly because the sublingual mucosa is highly vascularised and has a large surface area for absorption. In addition, drugs administered sublingually bypass the first-pass metabolism in the liver, which can enhance their bioavailability and rapid onset of action.

Question 33

The small intestine is the major site for administration for orally administered drugs. Why is this?

Answer 33

Because it has a large surface area for absorption and is highly vascularised. The small intestine also has a longer transit time compared to the stomach, which allows for more time for drug absorption to occur. In addition, the small intestine has a neutral to slightly alkaline pH, which is optimal for the absorption of most drugs.

Question 34

Compare the potential time of onset of action for drugs administered subcutaneously, intramuscularly and intravenously.

Answer 34

Subcutaneous and intramuscular drug administration typically have a slower onset of action compared to intravenous administration. This is because subcutaneous and intramuscular routes involve slower absorption and distribution of the drug into the bloodstream. Intravenous administration, on the other hand, delivers the drug directly into the bloodstream, allowing for rapid onset of action. However, intravenous administration can also pose a greater risk of adverse effects and requires careful monitoring.