Pharmacology

Question 1

What is pharmacology?

Answer 1

The study of the effects of a chemical substance on functioning of living organisms pharmacologically active chemicals are used to treat and cure disease

Question 2

What is pharmacodynamics versus pharmacokinetics?

Answer 2

Funko kinetics is how the body acts on the drug meaning how it is metabolised and pharmacodynamics is how the medicine acts on specific receptor sites in the body

Question 3

Describe the structure of a cell membrane and how this is important for its roles

Answer 3

The membrane is made up of two molecules lipid bilayer with a polar phosphate group which is hydrophilic and a nonpolar fatty lipid tail which is hydrophobic. The phospholipid bilayer allows the passage of organic molecules which are fat soluble through it, which is vital chemicals needed in cells.

Embedded in the phospholipid bilayer or proteins which are various roles some glycoproteins actors antigens whereas others allow the passage of organic molecules which are not fat soluble and ionic some of these proteins are fixed in place however some of them are fluid like floating icebergs and some require energy and some are simply gaps in the lipid layer allowing our substances through

Question 4

What is the fluid Mosiac model?

Answer 4

This is the model of the phospholipid bilayer with floating proteins to allow various types of transport

Question 5

Explain facilitated diffusion

Answer 5

Facilitated diffusion involves proteins in a membrane that allows passive diffusion down a concentration gradient. These can be proteins which form to remembrances which allow one specific type of molecule or ion to pass through for example potassium and sodium in the nervous impulses

Another form is through carrier molecules floating on the surface of the membrane. Each protein carrier is for a particular molecule. Once the substance is carried the molecule changes shape to move it through the membrane along the concentration gradient for example red blood cells have this to allow glucose to diffuse rapidly .

Regular diffusion occurs slowly down a concentration gradient and is seen in oxygen or carbon dioxide or lipid soluble molecules

Question 6

Explain active transport

Answer 6

This is an active process where molecules are moved against the concentration gradient by carrier proteins under the effect of the enzyme ATPase which catalyses the breakdown of ATP to ADP which provides the energy for the carrier protein to change shape and return to its original

Active transport carrier proteins are usually located all over the membrane and sometimes a specific for one molecule or multiple different molecules which need to compete based on which one has the highest concentration

An example of active transport is the sodium pump which actively pumps out sodium ions and pumps in potassium ions

The rate of active transport is dependent on temperature and oxygen concentration as they affect cellular respiration and the rate of production of ATP cells that known to carry out active transport contain very large numbers of mitochondria the site of aerobic cellular respiration ATP production poisons which stop ATP is from working also stop active transport including cyanide which inhibits cytochrome oxide is preventing production of ATP stopping in active transport

Question 8

What is phagocytosis and pinocytosis?

Answer 8

Phagocytosis or cell Eaton is when bacteria adjusted by white blood cells and pinocytosis cell drinking is when fluids are taken into minute vacuoles which happens commonly in the body for taking him extra exercise and fluid as a source of minerals and nutrients

Question 9

what is exocytosis

Answer 9

This is when membrane line vehicles fuse with the cell membrane and release their contents out of the fluid mosey structure

Question 11

What is titration?

Answer 11

This is when standard dosing needs to be customised to a patient to ensure the smallest effective amount of the drug can be given to minimise any side-effects

Question 12

Explain absorption in pharmacokinetics

Answer 12

This is the measure of how easily the medicine is absorbed into the body and solutions which are soluble in water or dissolved best as this makes up blur tissue fluid cytoplasm although it is also important to think about lipid solubility to get through the phospholipid bilayer. Some molecules can be both ionise and non-ionise depending on the environmental conditions to allow them to be absorbed better.

Once these drugs are taken into the body, they can be moved through bulk flow transfer such as the bloodstream or through diffusion

Question 13

Explain bio availability in pharmacokinetics

Answer 13

This is how much of the medicine is available to the body to have therapeutic effect and can be affected by how much of the medicine is put into the body how quickly it is excreted and broken down although it is very difficult to calculate as usually it would be an estimate based onconcentrations in the blood plasma although not all medicines absorbed from plasma into cells easily so it is not clear and each person absorbs things differently

Question 14

Explain distribution in terms of pharmacokinetics

Answer 14

The distribution of medicine describes where is found in the body for example some medicines accumulate in certain cells of tissues and higher concentrations creating drug reservoirs for example Auntie malarial agent QURINACRINE holds in the liver and the concentration in the liver is several times thousand that in the plasma

Fat has a similar role and as much of 70% of highly lipid soluble barbiturate thiopental may be present in the fat for three hours after administration

Question 15

Explain the role of the blood brain barrier

Answer 15

This is a barrier around the brain comprised of endothelial cells with tight junctions that do not allow water soluble molecules and microorganisms through other than water glucose and Geus elements although it does allow fat soluble elements which is why alcohol and nicotine can readily be absorbed past blood balloon barrier and cause Effect

The blood brain barrier protects the central nervous system from toxic medicine such as penicillin although it doesn’t protect always there is leaky areas such as the hypothalamus which can be exploited by pharmacological agents such as domperidone a dopamine antagonist which treats nausea and vertigo

Additionally, peptides including Bradykin in and enkephalins increase the permeability of the blood brain barrier can be used to improve penetration of chemotherapy during treatment of brain tumour

Question 17

What is the role of protein binding in the therapeutic effect?

Answer 17

Protein binding can be used when the therapeutic does not survive long enough in the blood on its own and it is instead bound to a protein such as albumin to help the drug be transported in the blood as a result the drug has time to reach the active site

Question 18

What is bio transformation or metabolism and why is it important in pharmaceutical use?

Answer 18

Transformation or metabolism is liver breaking down molecules two or more times into smaller molecules or adding extra molecules which make it easier for excretion.

When formulating drug product it’s important to consider the effect of the liver on drugs consumed into the gut through first past metabolism as this can affect drug efficacy

Each person has a different metabolism which is why we need clinical trials with thousands of patients and children and very young faces. Do not have the enzyme necessary to metabolised so drugs that are safe to adults can be very toxic to children.

Question 19

What is first past metabolism?

Answer 19

First-Pass Metabolism: Drugs taken orally are absorbed in the gut and pass through the liver before reaching circulation, where they may be metabolized.
• Phase 1 Reactions: Catabolic (oxidation, reduction, hydrolysis), making drugs more polar. Usually inactivates drugs but can sometimes make them more active or toxic. Mediated by P450 enzymes in the liver.
• Phase 2 Reactions: Another compound is added, making the drug highly polar and inactive for excretion in urine or bile. Occurs in the liver, lungs, and kidneys.
• Goal: Reduce lipid solubility and increase elimination.

Question 22

Explain how active tubular secretion works as a form of renal drug elimination

Answer 22

Active Tubular Secretion in Renal Drug Elimination

Active tubular secretion is a process by which the kidneys actively transport drugs and their metabolites from the bloodstream into the urine, helping eliminate them from the body.

How It Works:
1. Location: It occurs in the proximal tubule of the nephron (the functional unit of the kidney).
2. Transport Mechanisms: Specialized transporters on the tubular cells actively pump drugs from the blood (in the peritubular capillaries) into the tubular fluid. This is an energy-dependent process (requires ATP).
3. Types of Substances: This process is primarily used for eliminating charged (ionized) or polar drugs, metabolites, and waste products that are not easily filtered through the glomerulus.
4. Examples: Common drugs such as penicillin and certain diuretics are eliminated via active tubular secretion.

Two Independent Transport Systems:
1. Anion Transport System (for acids):
• Actively transports acidic drugs or anions (negatively charged molecules) from the blood into the tubular fluid.
• Example drugs: Penicillin, uric acid.
2. Cation Transport System (for bases):
• Actively transports basic drugs or cations (positively charged molecules) from the blood into the tubular fluid.
• Example drugs: Morphine, quinine.

Importance:
• It enhances elimination of substances that are not easily filtered.
• Helps remove waste products or drugs from the body, contributing to the regulation of drug levels in the bloodstream.
• It is important in drug interactions, as some drugs can compete for the same transporters, affecting their elimination.

In summary, active tubular secretion is a vital mechanism in renal drug elimination that actively removes drugs from the blood and excretes them in urine through two independent transport systems for acids and bases.

Question 23

Explain how half-life is important in elimination

Answer 23

Half life is a measure of the time it takes for the concentration of the medicine in the blood plasma to be half and it’s important in knowing when the patient needs to take a particular medicine

Question 24

How does the kidney affect elimination?

Answer 24

Firstly, through secretion through the proximal convoluted loop and the glamorous and two independent transport systems one for acid molecules and one for basis to achieve secretion as a renal drug elimination

Secondly, reabsorption as water is reabsorbed in the tubal which will happen freely if the tube is freely permeable to the drug molecules and most of the medicine will be reabsorbed passively back into the blood although many drugs are weak acids or weak basis so they change their ionisation state with pH making them easier to excrete through the kidneys. Some drugs like amphetamines are excluded more readily in acidic urine versus alkaline urine.

Question 25

In the context of pharmacodynamics, define affinity, efficacy, and potency

Answer 25

Affinity is the tendency of a drug to bind to the receptors It is governed by. Efficacy the tenancy of the drug to activate the receptor once it’s bound to it efficacy is the measure of the ability of the drug to produce the desired effect on the cells Potency is a combination of the two and gives the measure of the dose needed to produce a given effect. A low potency drug will require a large amount of drug to produce the minimum effect and vice versa.

Question 26

What are the main variability in effectiveness on a drug of an individual?

Answer 26

Age, genetics, pathology, ideological factors, ethnicity, pregnancy, drug interactions

Question 27

Explain how age has an effect on variability to intake a drug

Answer 27

The lax investigation into drugs on very old people as most of these tests are performed on younger people the same goes for children although the paediatric investigation plan which aids clinical trials in investigating in children came into effect similar to elderly where they have to be included in clinical data development Newborns and premature birth high risk of medicines like gentamicin which would cause oxide toxicity (damage to ears) in addition the glomerular filtrate of a newborn is only about 20% of the adult value and that’s 75 years only 50% as it falls on yeah adult Unexpected outcomes with children for example histamine and barbiturates sedate adults but I’ve been seen to cause hyperactivity drug elimination in particular in less efficient and very young and elderly people

Question 28

Explain the variability in drug potency in an individual as pregnant

Answer 28

Physiological changes such as a lower concentration of carrier protein albumin in the mothers blood which influences drug plasma binding and increased cardio output resulting in more renal blood flow and Glamer filtration therefore renal elimination of medicines is increased As the fetus doesn’t have enzymes necessary to break down the drug, they are extremely vulnerable

Question 29

Explain how drug to drug interactions can affect therapeutic potency

Answer 29

The most important adverse drug interactions occur with medicines that have serious toxicity and low therapeutic index so small changes may cause a significant adverse effect Food such as grapefruit react bad with statins and for warfarin, cranberries, broccoli and spinach can all interact to prevent the blood clot If medicines work together so the end result is equal to the sum of both medicines the effect is additive however if the effect is greater this is potentiation in the medicines are showing synergy

Question 30

Which medicine may cause the loss of one or more electrolytes from the body intern increasing the action of medicine and causing problems?

Answer 30

Thaizide diuretics cause a loss of potassium which can make digoxin medicine for congestive heart failure toxic to the patient

Question 31

Which medicine inhibits the enzyme that breaks down another medicine

Answer 31

Pethadine in the presence of a monoamine oxide days inhibitor

Question 32

Which medicine stimulate a breakdown of another so a higher dose of the second medicine is needed

Answer 32

Interactions with phenobarbitone and anticoagulant

Question 34

Explain personalised medicine

Answer 34

This is medicine which is grounded in recent developments to analyse the whole genome to tailor healthcare to an individual

Question 35

Explain agonist and antagonist

Answer 35

An agonist is a term used when a drug activates the receptors a successful agonist has high affinity and high efficacy. A partial agonist has a lower affinity for the receptor and cannot achieve the same maximum activation response of full agonist. An antagonist is a drug molecule that buys the receptor but does not activate it. They can be competitive where the binding is reversible if there’s a high enough agonist dose or irreversible where regardless of agonist dose the effect cannot be reversed

Question 36

Describe the most common root of administration of drugs

Answer 36

Oral administration which a medicine is readily absorbed through the upper digestive tract if there’s enough time for the medicine to reach site of action Sublingual under the tongue absorption is used when rapid response is required especially when the medicine is unstable in gastric acid or is readily metabolised by the liver taking advantage of the thin tissue under the tongue to readily absorbed drug e.g. nitrates used to treat angina how can I? How can I be? The guy who search everything but also be the guys I like. Rectal administration can be used in patients who are vomiting or unable to take medicine by mouth. Medicines are given in suppositories and animals are placed in the colon to produce a local effect or systematic effect but absorption following the rectal administration can be unreliable. It can be used to administer diazepam to children who are having an epileptic fit which it may be difficult to establish intravenous access. Topical or cutaneous administration involves ointment or creams used to get medicine to the blood through the skin although these are usually absorbed cooling additionally transdermal dosage by a stick on patch is used to produce a steady rate of drug delivery over a period of time for example, testosterone or oestrogen Lastly nasal sprays and eyedrops or forms of cutaneous administration Inhalation involves breathing Iglesius or volatile medicines which are absorbed directly into the blood through the alveoli and lungs as they have a large surface area and a rich blood supply. Inhaling is the fastest and most effective way of getting medicines to treat lung conditions, anaesthetics and asthma medication or routinely delivered to the lungs Glucocorticoids and bronchodilators are taken in this way Vaginal administration involves vaginal tablets or pessaries and they are usually used to deliver medicines to vaginal conditions like the rush would deliver a local hormone replacement therapy Perenteral administration is useful way of delivering medicines to inactivated or destroyed digestive tract which absorbed very poorly and medicines are usually administered to injection and they include subcutaneous (connective tissue) intramuscular (skeletal muscle ) and intravenous (vein fastest way and most controlled through intravenous trip)

Question 37

Explain the compartments models in pharmacokinetics

Answer 37

One compartment, the whole body is one entity and concentration of medicines in the tissue two concentration of the medicines in the blood plasma Two compartment model divides the body into central tissues which have a rich blood supply such as heart lungs, kidney liver, brain and the peripheral tissues such as fat and skin. Where is the medicine is administered to the central tissues and distribute itself to the peripheral regions. Multi compartment model the body is comprised of a number of different compartments which is administered and spreads out to all the others