Unit 3 Flashcards
1
Q
What are the main functions of the skin?
A
- Protection
- Thermoregulation
- Cutaneous sensation (touch)
- Excretion
- Absorption
- Vitamin D synthesis
2
Q
What are the benefits of transdermal drug delivery?
A
This is a painless method which is useful for slow-release drugs or for poorly-soluble suspensions
* Bypass the digestive system
* Avoid first-pass metabolism
3
Q
What are examples of drugs administered transdermally/topicaly?
A
- Nicotine (transdermal patches)
- Clotrimazole (anti-fungal medication)
- Lidocaine (local anaesthetic)
4
Q
What are the two categories of the skeletal system and what do they consist of?
A
- Axial: This is the central core consisting of 80 bones including the skull, vertebrae, ribs and the sternum.
- Appendicular: this consists of 126 bones and includes the bones that make up the upper and lower limbs.
5
Q
What are the five classification of bones?
A
- Long: Consists of a long shaft and includes the bones of the thigh, leg, arm & forearm.
- Short: Consists primarily of spongy bone including the bones of the wrist and ankle.
- Flat: These are thin and usually curved including the bones of the cranium.
- Irregular: These are primarily spongy bones covered with a thin layer of compact bone including the vertebrae and bones in the skull.
- Sesamoid: Develop in some tendons crossing the ends if long bones & includes the patella located at the knee.
6
Q
What are the two circuits of the circulatory system and what are their functions?
A
- Pulmonary Circuit: Carries deoxygenated blood into the lungs, occurs before blood returns to the heart.
- Systematic Circuit: Delivers the oxygenated blood from the heart to the tissues before collecting deoxygenated blood & sends it to the heart with unused nutrients and metabolic waste products. These extra substances filter in the liver.
7
Q
What is the function of the heart and what is contained within it?
A
It is a muscle which acts as a pump & contains 4 chambers:
* Atria (left and right): collects blood
* Ventricles (left and right): pumps blood out
Valves- prevent the back flow of blood
Muscular Septum- divides the heart in two sections where the right side pumps deoxygenated blood and the left side oxygenated blood.
8
Q
What is cardiac output and how is it calculated?
A
This is the amount of blood per litre pumped out of the heart per minute (5.6L in male & 4.9L in female).
Heart Rate (HR) x Stroke Volume (SV).
9
Q
What is stroke volume and how is it calculated?
A
This the amount of blood collected in the ventricles when at full capacity and about to contract. This varies depending on whether in rest or exercising.
10
Q
What is the structure and function of the blood vessel artery?
A
Arteries: Transports blood towards the tissues and away from the heart & contain thick muscular walls which can withstand blood under high pressure.
11
Q
What is the structure and function of veins?
A
Veins: Carrie blood away from the tissues and towards the heart. Contain blood under low pressure and valves to prevent the backwards flow of blood.
12
Q
What is the structure and function of capillaries?
A
Capillaries: One-cell layer thick endothelial lining-tolerate blood under low pressure due to moving slower & gas exchange has a chance to take place. This is where the exchange of gases, water & waste products takes place as the walls are fenestrated. Cappiliries then collect into venules. Capilliries connect arterioles and venules.
13
Q
What are the four major components of blood?
A
- Plasma: fluid that surrounds the blood cells and helps transport CO2, hormones & metabolic waste products.
- Red Blood Cells (erythrocytes): formed in the bone marrow and function as mainly O2 carriers.
- White Blood Cells (leukocytes): created in the bone marrow & make up the bodies immune system by producing antibodies & help destroy harmful microorganisms.
- Platelets: cells clumped together to form blood clots & help protect the body by preventing bleeding.
14
Q
What forms the superior and inferior vena cava?
A
- Superior Vena Cava: The merging of the veins carrying blood from the head, neck, and upper limbs which travels towards the heart.
- Inferior Vena Cava: The merging of the veins from the legs, pelvic structures and abdomen traveling upwards.
15
Q
Where does blood travel to from the left ventricle?
A
Blood moves into the aorta (supplying the head and arms) and back behind the heart, and then dropping down through the thorax and abdomen, suppling the organs.
16
Q
Where does the blood move to from the superior and inferior vena cava?
A
The blood drains into the right atrium, then into the right ventricle, and to the lungs (via the pulmonary arteries).
17
Q
Where does blood travel to from the lungs?
A
Blood travels back via the pulmonary veins, into the left atrium and then the left ventricle to travel around body again.
18
Q
What are the two types of administration of drugs?
A
- Drugs may be absorbed directly into the systematic circulation via sublingual.
- Buccal administration is another method which provides a useful route for rapid absorption and action- particularly useful for nausea medication, painkillers, or drugs for acute symptoms such as those in angina.
19
Q
What is the importance of rectal administration?
A
This is important in drug delivery, providing a better bioavailability than oral route as it avoids the stomach & also first pass metabolism. This method also reduces side-effects such as gastric irritation, nausea and vomiting.
20
Q
What is the function of the hepatic portal system?
A
This is the route by which blood drains from the intestines via the mesenteric veins, into the splenic vein, before moving across towards the liver as the hepatic portal vein. Blood passes through the hepatocytes of the liver before draining into the hepatic veins & then returns to the systematic circulation.
21
Q
What is the importance of the renal system?
A
It is important in the filtration and excretion of substances from the body and the urinary system for both excretion of drugs from the body and metabolic diseases such as diabetes.
22
Q
What is the renal/ urinary system composed of and where do these components lie?
A
This system is composed of of the paired kidneys and ureters with a single urinary bladder and urethra, where the kidneys lie laterally to the vertebral column in the level of the T12-L3 vertebrae whereas the right kidney is lightly lower due to the larger size of the liver.
23
Q
What does the Central Nervous System consist of & what is it protected by?
A
This consists of the brain and spinal cord which is surrounded and protected by the meninges, consisting of three layers (the dura matter, the arachnoid and the pia mater). It is also surrounded by the cerebrospinal fluid.
24
Q
What is Blood-brain barrier (BBB) and what is its function?
A
This is the barrier between the CNS and the rest of the body which is important in protection and accessibility as the tightly-connected endothelial cells in the BBB ensure only substances capable of passing through the endothelial capillary cells, or which are actively transported can cross into the CNS.
25
What is the function of cerebrospinal fluid?
* Clear colourless liquid found in the brain and spinal cord.
* Acts as a cushion/buffer, protecting the brain.
* Contains small amounts of protein, glucose and potassium.
* Contains relatively large amounts of NaCl.
* Produced within the brain & no cellular component
* Can be sampled to aid diagnosis of certain conditions (meningitis).
* Maintains its own pressure, measured to diagnose or treat illnesses.
26
What is lumbar puncture?
This is a test involving a needle being inserted into the lower back (collection of nerve roots), between the bones in the spine to diagnose conditions affecting the brain, nerves and spinal cord (cancer, multiple sclerosis, Guillian-Barre syndrome), examining spinal fluid.
27
What is the difference between epidural and intrathecal?
* Epidural: Administration of drugs onto the epidural space (outside dura mater).
* Intrathecal: Administration of drugs directly into the CSF into the intrathecal (subarachnoid) space.
28
What is the difference between epidural and intrathecal?
* Epidural: Administration of drugs onto the epidural space (outside dura mater).
* Intrathecal: Administration of drugs directly into the CSF into the intrathecal (subarachnoid) space.
29
What is the endocrine system responsible for?
It is responsible for producing hormones which regulate metabolism, growth and sexual function.
30
What are the four types of tissue?
* Epithelial: Line the body cavities, forming the outside surfaces of internal organs, modified to form glands.
* Connective: Connect tissues, proving framework.
* Muscular: Cardiac muscle-restricted to the heart, Skeletal-allows joint movement, Smooth-found in the tubular structures such as the gut, blood vessel, eye.
* Nervous: Specialised cells in the CNS & peripheral nervous system are used for processing information & integragating functions in the body.
31
What are the four specialised functions of epithelial cells?
* Physical Protection: Dehydration, physical damage, prevents/limits the penetration of bacteria, solvents, chemicals.
* Sensation: Contains sensory nerves, providing sense of touch, tase, sight, smell, hearing from neuroepithelial.
* Control absorption & uptake of material: Materials entering/exiting pass through epithelia ( GI tract & Kidney). These cells alter the their permeability.
* Secretion: Can coat the surface of tissue providing lubrication & physical protection/as chemical messengers if systematically absorbed.
32
What is glandular epithelium ?
This is referred to when all the epithelial cells in a tissue are able to secrete fluids. These are specialised to produce and secrete ( release substances), found in the glands such as hormones, proteins and water.
33
What are the four types of simple epithelium?
* Squamous: Thin, flat with a central nucleus- found in alveoli, lining blood vessels & kidney glomeruli, shape allows affective diffusion.
* Cuboidal: Cubed shape with large central nuclei- found in kidney tubules, small glands & ovary. Exo/endo
* Columnar-Ciliated:Tall, thin, rectangular with cilia- bronchi, fallopian tubes, parts of uterus- bathed in mucus from glands to maximise ciliary function.
* Columnar-Non-Ciliated:Tall, thin, rectangular without cilia- GI tract, from the stomach to the anal canal-allow absorption.
34
What are the four types of stratified epithelium cells?
* Squamous: Those at the free surface- forms the epidermis of the skin & lines the oesophagus & mouth
* Cuboidal: 2 layers of cuboidal cells- largest ducts of the salivary, sweat & mammary glands with protective role.
* Columnar:Those at the free surface- found in epiglottis, anus, ducts of salivary glands, male urethra with protective & secretary role.
* Transitional Epithelium: Cuboidal/columnar- urethra- epithelia can undergo repeated stretching to either squamous or cuboidal shape.
35
What is avascular?
This is the term used for epithelial cells as they are tightly arranged, leaving no space for blood vessels therefore their nutritional requirements have to travel either downwards from the exposed apical surface or up through the basal lamina.
36
Why is a high level of regeneration necessary for epithelial cells?
Epithelial cells shed regularly or get damaged as they are exposed to high level of direct contact with the outer environment.
37
What are the 4 major types of specialised cell junctions used for intracellular connections?
* Tight Junctions: Binds cells closely together, preventing water passage, useful in the small intestine, isolating them from the liquid present in the lumen.
* Gap Junctions: Enable small molecules to pass between connected cells, used to coordinate various activities such as the beating of cilia.
* Desmosomes: Enable the epithelium to withstand mechanical stresses.
* Hemidesmosomes: Connect each cell to the extra cellular filaments of the basal lamina.
38
What is the role of the basement membrane?
Stick epithelium to connective tissue, also porous allowing material to move between the epithelial & connective tissue layers. Comprised of 2 layers, with the layer closest to the epithelial cells being basal laminated, and the layer connecting directly to the connective tissue being the reticular lamina.
39
What is the difference between mucous membranes and serous membranes?
Both are internal membranes that line cavities. However, mucous membrane has direct contact with the outer environment such as digestive, reproductive & respiratory tracts also has the ability to secrete mucus, either as lubricant, protective lining or to aid digestion & absorption. Serous membrane does not have direct contact & includes pericardial membrane, pleural membrane, peritoneum also has the ability to secrete serous fluid,decreasing friction between adjacent surfaces, acts as water-tight barrier, preventing fluid accumulation.
40
What is the difference between cutaneous membrane and synovial membrane?
Cutaneous membrane is an external membrane, lining body cavities whereas synovial membrane is internal lining moving joints.
Cutaneous is comprised of stratified squamous epithelium on top of layer of areolar & adipose tissue connected to layer of dense, whereas synovial has no epithelia just connective tissue & has the ability to secrete synovial fluid-lubricating the joint.
41
What is the difference between endocrine and exocrine glands?
Endocrine secret hormones directly into the interstitial fluid, diffusing into the blood, influencing cell function. This includes thyroid, pancreas, thymus, endocrine cells in GI tract.
Exocrine produce secretions that travel thru DUCT to be released into endothelial surface, including tears, sweat & breast milk.
42
What is the difference between apocrine secretion and holocrine secretion?
Apocrine occurs when the apical side of each cell buds & splits from the main cell-more damaging than merocrine but cells scan repair themselves, replace secretary products & release again.
However, holocrine is a destructive process, where matured cells burst to release their products, eventually being entirely replaced. This includes hair follicles releasing sebum.
43
What are the three types of muscle tissue?
* Skeletal: Thon and long,myocytes also referred to as muscle fibres consist of several cytoskeletal filaments of actin+myosin. Signal to contract received-myosin proteins pull on the actin causing temp shortening. Striated voluntary.
* Cardiac: Striated with actin & myosin-shorter than skeletal, performs highly coordinated action. Myocardiocytes are branched & joined with intercalated disks, representing 2 neighbouring membranes joined together. Striated involuntary.
* Smooth: Occurs in hollow organs (bladder, respiratory, GI tract, reproductive tracts, walls of blood vessels)- do not contain actin/myosin therefore not striated. Under the control of NS referred to as non-striated muscle.
44
What are the 2 types of cells which comprises the nervous tissue?
* Neurons: Referred to as nerve fibre (1m in length) consists of large cell body, nucleus, dendrites,axon & myelin.
* Neuroglia/Glial Cells: Variety of cells surrounding the neurons fixing them in place & insulating them. Provide nutrients to the neurons, remove pathogens & dead neurons.
45
What are the roles of connective tissue?
* Makes the framework.
* Endoses ans separates those organs.
* Plays a protective role.
* Involved in body’s immune system.
46
What are the 3 types of extracellular fibres?
* Elastic fibre: Made of elastin, branched, stretchy material which can spring back to og shape.
* Reticular fibre: Branched network of fibres, strong in many directions, hold organs & their supporting tissue.
* Collagen fibre: Long, unbranched materials form tendons & ligaments & the support structure in the heart and liver.
47
What is role of mesenchymal cells?
Stem cells which divide upon tissue damage/inflammation then differentiate into various permanent connective tissue cells.
48
What is the role of fibroblasts?
Most abundant cell type, largely responsible for creating the matrix. Creates the protein subunits that join together to form the extracellular fibres.
49
What is the role of melanocytes?
Present in tissues such as the eye & skin dermis, producing the pigment melanin.
50
What is the role of mast cells?
Mediators in inflammation, found near blood vessels, their intracellular granules contain histamines causing vasodilation and heparin which inhibits excessive bleeding.
51
What is the difference between loose (LCT) and dense connective tissue (DCT)?
The extracellular matrix in LCT is loosely packed, leaving large spaces in between whereas in DCT they are densely packed. LCT provides support+flexibility as well as nutrient+waste exchange and cushioning + insulation. However, DCT provides strength+support to where tension is applied as well as protection by covering the organs, resisting stretching.
52
What are the 3 types of LCT?
* Areolar Tissue: Separates skin from muscles beneath, allowing muscles to bulge+flex without tearing.
* Adipose Tissue: Underlies the skin, particularly in the buttocks,breasts&flanks. Insulates the body from heat loss,protect the organs from physical shock. Acts as an energy store.
* Reticular tissue: Used to build complex structure to support the action of functional cells- liver, kidneys, spleen, lymph nodes & bone marrow.
53
What are the 3 types of DCT?
* Regular: Fibres running in parallel directions, concentrating strength of tissue in that direction-tendons & ligaments.
* Elastic: Elastic fibres are dominant, tough yet springy, can cushion surrounding from physical shock.
* Irregular: Predominantly collagen, in branched, interconnected network-material equally strong in all directions-protects liver,kidneys & spleen, surrounds joint cavities & coats the outside of cartilage+bones.
54
What is bone made of and what do they provide?
Made up of flexible collagen-fibre matrix, filled in with a hard mineral substance known as hydroxylapatite. This material provides rigidity & strength but flexibility is provided by the collagen matrix, ensuring bone is not brittle.
55
What are the 3 types of cartilage?
* Hyaline: Tightly packed collagen fibres, allows flex& strength- forms cartilage of respiratory tract+nose, covers bone surface in joints, prevents friction, wearing-protected by synovial fluid.
* Elastic: High amount of elastin fibres, allows structure to return back to shape- forms the outer ear, aural tube, epiglottis+parts of larynx.
* Fibrocartilage: Tightly packed collagen fibres with little ground substance- very resilient to mechanical stress but difficult to repair after injury- makes pads between the vertebrae, pubic bones+inside knee joints.
56
What is the granular type of white blood cell?
Granulocytes: Contains small amounts of protein granules. Consists of 3 types which are attracted to sites of tissue injury/inflammation including basophils, eosinophils & neutrophils.
57
What are the 2 types of agranular white blood cells?
* Monocytes: Move from blood to tissues(site of infection), undergo structural changes to become macrophages.
* Lymphocytes: Both B+T cells can recognise antigens on invading pathogens/body materials that have been inappropriately modified/damaged- another types includes natural killer cells-identify & terminate invaders without antibodies, speeding immune response.
58
Where are interstitial fluid found and what is their role?
They are found surrounding tissues and helps bring oxygen and nutrients to cells & removes waste products from them. These fluid accept water, solutes & dissolved gases which pass through the capillary endothelial junctions and then becomes blood once it returns through the capillaries into the veins.
59
What factors control the onset, duration and intensity of a drugs action after administration?
1) Rate at which the drug reaches its site of infection.
2) Concentration of the drug.
3) Metabolism of the drug in the body.
4) Rate of excretion of the drug.
5) Sensitivity of the individual to the drug.
60
What are the process for how drugs move in & out of the body, and when do they stop working together?
The process includes Absorption, Distribution, Metabolism & Excretion. These processes occur until:
* All of the drug is absorbed (from GI tract/injection site).
* All of the drug has been metabolised, & the parent drug is no longer detectable in the blood.
61
Describe the key processes of drug movement in the body?
ABSORPTION: After drug is made available to oral drugs peak in 1-2 hrs; IV is the fastest route.
DISTRIBUTION: Drug spreads where there is blood flow where organs with high blood flow (heart,liver, kidneys) absorb drugs first.
METABOLISM: Chemical structure of the drug is changed for easier excretion. Urine drug tests detect metabolites, not original drug.
EXCRETION: Eliminating the drug through urine but also lungs,bile,sweat & other fluids.
62
What are the 2 methods used to absorb drugs and where do they commonly take place?
* Commonly absorbed by passive diffusion but active transport can also take place.
* Usually occurs in the GI tract from the stomach to the rectum but commonly in small intestine due to:
1) High movement
2) Large surface area
3) Good blood flow
4) Optimal pH (5-7)
* Other parts of GI tract absorbs less efficiently.
63
What are the factors affecting the rate at which drugs are absorbed in the body?
* Gastric emptying: Stomach takes longer to empty after severe trauma or conditions causing nausea & vomiting.
* pH: pH of GI contents can impact drug absorption (existing in unionised and ionised form).
* Weak acids and bases: non-ionised easily absorbed due to being more lipid-soluble. Weak acids better absorbed in upper GI tract where more acidic, remaining in the un-ionised form.
64
What is pH partition hypothesis?
Only the unionised form can cross a membrane and that the concentration of the unionised form on each side of the membrane will be equal.
65
What factors determine a drugs ability to cross cell membranes and be absorbed?
The drug must be soluble in the lipid material of the membrane to enter the membrane and soluble in the aqueous part of the membrane to exit the membrane.
66
What factors affect a drugs entry into tissues and its distribution in the body?
* Blood flow: Higher blood flow, quicker delivery.
* Tissue mass: Larger tissues can hold more drug.
* Partition Characteristics: The drugs ability to cross the blood-tissue barrier.
67
What is the effect of large exposure to drugs over time?
It may affect the pharmacological response of a drug by altering its potency/duration of action, however the metabolites of drugs are more polar & water soluble than the parent drug therefore more likely to be excreted. Metabolism converts active compounds into less active & less toxic compounds.
68
What is excretion and its site of mechanism?
Process by which drug is irreversibly transferred from systemic circulation to extracorpotal fluids (urine/bile). Kidneys (renal excretion) & liver (biliary) are responsible for this. Lungs can excrete volatile substances, while drugs can be excreted in sweat, saliva,tears& breast ilk which is more acidic than plasma. This is crucial for estimating drug volume administered to the baby.
69
What is the excretory system made up of?
* 2 kidneys
* Ureters
* Bladder
* Urethra
* with branches of 2 renal arteries and veins
70
What are the 3 processes which occur in the kidneys nephron (kidney tubule)?
* Glomerular Filtration: Small drug & ,metabolite molecules, those not bound to plasma protein-filtered from the blood. Opposite is poorly excreted.
* Tubular Secretion: Entering of most drugs involving active transport against concentration-requires energy & carriers for drugs like dopamine+histamine
* Tubule Reabsorption: Some drugs are reabsorbed back into the bloodstream-passive transport.
71
What is the importance of biliary excretion?
Important route for the elimination of some drugs via the biliary tract & factors which determine its elimination are the chemical structure, polarity & molecular size as well as characteristics of the liver such as specific active transport sites within the liver cell membrane.
72
What are prodrugs and what are the reasons to use these?
These are inactive drug precursors that release the active drug on chemical/enzymatic transformation.
* Modifying drug uptake & distribution
* Altering solubility
* Masking toxicity & other undesirable effects
* Modifying the duration of action
* Masking unpleasant taste
73
What are the benefits of esters in drugs?
* Improves solubility,enhancing absorption.
* Increases stability, protecting from hydrolysis & degradation during storage.
* Controlled release of active pharmaceutical ingredients,improving therapeutic efficacy.
74
What is the effect of aspirin as a prodrug?
It reduces side effects (gastric bleeding) due to the phenolic group in the salicylic acid.
75
What is Cmax, Tmax, MEC and MTC?
Cmax= maximum concnetration
Tmax= rate of elimination
MEC= minimum effective concentration (the concentration required for the drug to show an effect)
MTC= maximum tolerated concentration (increasing concentration above the level will have little effect.
76
What is the importance of the rate of release of a drug?
If the drug is absorbed at too high levels, the chance of side effects will increase.
If the drug is absorbed too slow, the level of drug in the blood will not reach the required level and will be ineffective.
77
What is bioavailability and how is this different from IV and other routes of medication administration?
This is the fraction of an administered drug that reaches the systematic circulation. Bioavailability of IV is 100%, however other methods of administration is lower due to incomplete release of the dosage form, incomplete absorption & first-pass metabolism
78
How is bioavailability calculated ?
(Oral AUC/IV AUC x IV Dose/Oral Dose) x100
79
What is bioequivalence?
When 2 products are bioequivalent they are expected to behave in the body for all intents and purposes the same.
80
What is volume distribution (Vd)?
This is the volume in litres in which the amount of drug would need to distributed in order to produce the observed blood concentration.
Vd= total amount of drug (mg) in the body/
Drug blood plasma concentration (mg/L)
81
How does volume distribution and plasma concentration link?
* Large Vd= greater extent of drug distribution in the tissues therefore LOW plasma conc is high Vd.
* Drugs which remain in the blood circulation tend to have LOW Vd.
82
What is the significance of drug-plasma protein binding of drug-plasma protein binding in pharmacokinetics?
* Reversible reaction which creates an equilibrium between bound and free forms.
* Only free drug molecules can cross membranes.
* Creates reservoir effect, prolonging the duration of action.
83
What are the 2 classifications of plasma-protein binding of drugs?
* Restrictive binding: Occurs when Vd is <0.6 L/Kg, indicates significant binding to plasma proteins, limiting drugs distribution.
*Non-Restrictive binding:Occurs when Vd is <0.6 L/kg
Indicates tissues binding is stronger than plasma protein binding, allowing freely distribution.
84
What are the clinical implications of drug-plasma protein binding changes?
* Low plasma protein may occur due to aging/malnutrition, leading to higher free drug conc.
* Increased free drug may enhance efficacy,side effects, requiring dosage adjustments.
85
What is clearance?
This is the efficiency of the irreversible elimination of drug from the systematic circulation. It is the measure of the volume of blood cleared per unit time. High conc in the plasma= overall high elimination.
High clearance= drug is removed quickly
Low clearance= drug is removed slowly
Measured in L/h or ml/min
86
What is half life of a drug?
This is the time taken for the concentration of the drug in the plasma to drop by half.
In 1st order reaction, the higher the concentration of drug in the system, the faster the rate of elimination.
87
Describe the relationship between half-life, clearance and volume of distribution?
* Drug with same clearance but higher Vd= longer half-life.
* Drug with same Vd but higher clearance= shorter half-life.
88
Describe the relationship between steady sate and infusion rate.
* During initial phase, drug infusion rate exceeds elimination rate, causing plasma conc to rise.
* The elimination rate depends on concentration. Rate= clearance x concentration
* Steady state is reached when infusion rate = the elimination rate, constant concentration.
* Once infusion stops, plasma concentration drops.
89
How is steady state achieved?
This is when doses if given in regular time intervals so that the drug concentration does not reach 0 and therefore drug accumulates in the body and steady sate is achieved.
Higher the dose, the higher the steady state.
90
What is loading dose?
This is used for drugs with long half life, or in emergency situations to rapidly increase the plasma concentration up to the level that is required in steady state and give immediate effect.
91
What is the equation to calculate steady state concentration?
Concentration= Dose (mg) / Dose Interval (hr) x Clearance
92
What is the difference between linear & non-linear pharmacokinetics?
Linear= plasma conc rises in a linear way with an increase in dose. 1st order kinetics
Non-linear= shows a rapid rise (or a levelling off) as the dose increases. 0 order kinetics
93
What happens if the absorption process is saturated?
The drug is only absorbed at a fixed rate, independent of concentration, leading to decreased bioavailability. E.g. amoxicillin.
94
What occurs if the distribution step is saturated?
More free drug becomes available & the volume of distribution (VOD) increases. E.g. naproxen.
95
How can liver metabolism affect drug clearance?
The metabolic process can be restricted (inhibited) or enhanced (induced), affecting liver clearance (CLH). E.g.
* High doses of propranolol ↓ clearance (reduced liver blood flow)
* High doses of carbamazepine ↑ clearance (increased metabolism)
96
How do penicillin G and ascorbic acid (vitamin C) affect kidney drug clearance?
Penicillin G: saturates active secretion → ↓ clearance
Ascorbic acid: saturates active reabsorption → ↑ clearance
97
What is Therapeutic Drug Monitoring (TDM)?
Regular monitoring of plasma drug concentrations, especially important for drugs with narrow therapeutic indices or nonlinear pharmacokinetics.
98
What is anterior?
Towards the front of the body, in front of.
99
What is posterior?
Towards the back of the body, behind.
100
What is superior?
Above, on top of.
101
What is inferior?
Below, underneath.
102
What is lateral?
Away from the midline of the body, towards the sides.
103
What is medial?
Towards the middle/midline of the body.
104
What is superficial?
Towards the external surface of the body (skin).
105
What is deep?
Away from the body surface, towards the inner body.
