Pharamcology study

Question 1

Distribution?

Answer 1

Drug moves from blood to tissues (affected by perfusion, membrane crossing ability, protein binding and volume of distribution) /Distribution is the process by which a drug is dispersed throughout the body’s blood and tissues. After a drug enters into systemic circulation by absorption or direct administration, it will pass from vascular spaces to tissues where a drug-receptor interaction will occur, creating the effect of the drug.

Question 2

how does Metabolism work?

Answer 2

Metabolism is the enzymatic conversion of a drug into a metabolite. This process is crucial for making drugs more easily eliminated from the body by increasing their water solubility, thus facilitating their excretion through urine or bile. (Liver mainly transforms drugs (phase 1= cyp450 oxidation/reduction; Phase 2 = conjugation))

Question 3

Excretion?

Answer 3

Drug excretion is the removal of drugs from the body, either as a metabolite or unchanged drug. There are many different routes of excretion, mainly the urine and bile. The most important organs for excretion are the kidney and liver.

Question 4

First pass Metabolism?

Answer 4

drug metabolism at a specific location in the body which leads to a reduction in the concentration of the active drug before it reaches the site of action or systemic circulation. (Drugs like GTN lose potency via liver first-pass effect)

Question 5

Bio-availability

Answer 5

The ability of a drug to be absorbed and used by the body

Question 6

Volume of distribution (Vd)

Answer 6

How extensively a drug distributes into body tissues.

Question 7

Receptors

Answer 7

Where drugs act
Ligand-gated ion channels - Fast (nicotinic)
GPCRs- Seconds (adrenergic, muscarinic)
Enzyme-linked - = hours
Nuclear - Gene transcription (slowest)

Question 8

Affinity

Answer 8

How strongly a drug binds to a receptor (high affinity means lower dose needed)

Question 9

efficacy

Answer 9

the ability to trigger a response after binding (maxim response achievable from a drug, measured by E max (the maximal effect)

Question 10

Potency

Answer 10

Dose needed for maximal effect (higher potency=lower dose needed) (measured by EC50- the concentration that produces 50% of the maximal effect)

Question 11

Therapeutic index (IT)

Answer 11

Wider=safer (panadol) Narrow=Risky (warfarin)

Question 12

Agonists

Answer 12

Activates receptors (full, partial)

Question 13

antagonists

Answer 13

Block receptors (competitive or non-competitive)

Question 14

Inverse agonists

Answer 14

A compound that binds to and prevents constitutive receptor activity in the absence of an agonist (Produce opposite affects)

Question 15

2nd pass metabolism (phase 2)

Answer 15

Phase II metabolism, the second stage of drug metabolism in which a drug is conjugated with an endogenous molecule, increasing its water solubility and facilitating excretion. This contrasts with phase I, where a drug is modified, often by enzymes like cytochrome P450s

Question 16

glucose can be found in different forms, what are they?

Answer 16

Monosaccharides (mono=1) - simplest form of carbohydrates/sugar. cannot be broken down (e.g glucose gel)
Disaccharides (di=2) double sugar formed glucose and frutose.
polysaccardis (poly=multiple) complex carbohydrates.

Question 17

what is the autonomic nervous system?

Answer 17

the autonomic nervous system controls involuntary bodily functions like, HR, digestion, respiration and pupil size. Its divided into the sympathetic nervous system (fight or flight) and Parasympathetic nervous system (rest and digest)

Question 18

Receptor effect? (mnemonic ABCD - a, always constricts, B alsways Dilates)

Answer 18

Alpha 1 receptors – affect Arteries (vasoconstriction and smooth muscle contraction)
Alpha 2 - affect brain and peripheral (neurotransmitter realease)
Beta1 – affects heart (increasing heart rate and contractility)
Beta2 – affects Bronchidilation - (widening of airways)

Question 19

what is somatic nervous system?

Answer 19

somatic nervous system is a component of the peripheral nervous system associated with the voluntary movements of the body via the the use of skeletal muscles. As well as specialized sensory receptors for detecting information within and outside the body

Question 20

what functions are the somatic nervous system responsible for?

Answer 20

it is responsible for all the functions we are aware of and can consciously influence. this includes movement of arms, legs and other parts of our body. The somatic senses (mechanoreception, thermoreception and pain) are the mechanisms by which sensory information is gathered (are distinct from the special senses. (V,H,T,S,Equilibrium)

Question 21

what factors affect absorption?

Answer 21

1. route of administration: oral drugs go through 1st pass metabolism by the liver whereas IV bypass this process.
2. Solubility: lipid-soluble drugs cross membranes more easily
3. PH: Drugs better absorbed in certain environments (like acidic drugs - stomach)
4. Blood flow: More blood flow increases absorption
5. surface area: The small intestine’s large surface area allows for better absorption than the stomach.
6. Contact time: Gastrointestinal motility, faster transit time (e.g., in diarrhea) can reduce absorption.

Question 22

what are the three Types of Glucose in Treatment?

Answer 22

1. Glucose gel, is a simple form of pure sugar that is absorbed quickly. (must be able to self administer).
2. Glucose 10% - Symptomatic hypoglycaemia (with the inability to self-administer oral glucose). It is a sugar that is the principle energy source for body cells, espically the brain.
3. Glucagon - is a hyperglycaemic agent that mobilizes hepatic (liver) glycogen. it is essential a hormone that raises blood glucose levels. we give this when that patient has the inability to self administer oral glucose

Question 23

what is the Asthma pathway?

Answer 23

1. exposed to allergen, cold air or exercise
2. immune activates, mast cells release histamine.
3. Bronchoconstrication, narrows airways
4. inflammation, worsens obstruction

Question 24

treatment of asthma?

Answer 24

1. Sulbutamol: Rapid B2 agonist (causes bronchodilation in the lungs)
2. Ipratropium: Anticholingeric (also a brochodilater)

Question 25

what does your management plan look like?

Answer 25

1.Provisional Diagnosis: Based on symptoms/vitals. 2. Indications: Why you’re giving the drug. 3. Mechanism of Action: How the drug works. 4. Contraindications: When NOT to give. 5. Precautions: What to monitor. 6. Side Effects: Expected adverse events. 7. Link to Pathophysiology: Explain why the drug helps the underlying problem

Question 26

Pharmacodynamics?

Answer 26

The study of the biochemical, physiologic, and molecular effects of drugs on the body (what a drug does to the body)

Question 27

Pharmacokinetics?

Answer 27

The study of absorption, distribution, metabolism, and excretion of drugs by the body. (what the body does to the drug or how the drug is process by the body)

Question 28

Zero order Kinetics?

Answer 28

reactions where the rate is not affected by the concentration of the drug used. In other words, the rate of the reaction is constant, regardless of how much reactant is present e.g phenytoin

Question 29

First-order kinetics?

Answer 29

First-order kinetics describe the elimination rate, the rate of elimination is proportional to the drug's concentration. This means that the higher the drug concentration, the faster the elimination rate. Most drugs are eliminated through first-order kinetics (water in a barrel)

Question 30

Hypovolemic shock

Answer 30

Primary Problem: Decreased central venous pressure (CVP) due to volume loss. • Treatment: Rapid intravenous fluid resuscitation to restore preload and maintain perfusion. • Vasopressors: May be used temporarily if hypotension is profound. • Inotropes: Not indicated; may worsen tachycardia.

Question 32

Cardiogenic shock

Answer 32

Primary Problem: Decreased cardiac output due to pump failure. • Treatment: Inotropes to improve contractility and support cardiac output. • Intravenous Fluids: Not indicated; may worsen pulmonary congestion. • Vasopressors: Generally contraindicated.

Question 33

Obstructive shock

Answer 33

Primary Problem: Mechanical obstruction to circulation. • Treatment: Relieve the obstruction (e.g., needle thoracostomy for tension pneumothorax). • Response to Fluids/Vasopressors/ Inotropes: Often minimal or short-lived

Question 34

Distributive shock

Answer 34

Primary Problem: Decreased systemic vascular resistance (SVR). Treatment: Vasopressors to restore vascular tone and maintain perfusion pressure. Intravenous Fluids: Required due to concurrent hypovolemia or maldistribution of fluids. Inotropes: May be helpful in patients with sepsis-induced cardiomyopathy.