This document provides an overview of pharmacology concepts including:
- Pharmacokinetics describes what the body does to drugs through absorption, distribution, metabolism and excretion.
- Pharmacodynamics describes what drugs do to the body through receptor interactions and clinical effects.
- Key pharmacokinetic processes like absorption, distribution, metabolism and elimination are influenced by drug and body factors and determine drug availability at target sites.
Pharmacology: Class Session 1 and 2 Introduction to PharmacologyMariaJose2001
This is an outline of the basics of Pharmacology. A discussion of how drugs are named, classified and its effects on the person's biochemical processes. It also included the factors influencing drug action and potential drug interactions. At the end, some commonly ysed terminologies were defined.
Pharmacology is the branch of pharmaceutical sciences which is concerned with the study of drug or medication action, where a drug can be broadly defined as any man-made, natural, or endogenous molecule which exerts a biochemical or physiological effect on the cell, tissue, organ, or organism
Pharmacology: Class Session 1 and 2 Introduction to PharmacologyMariaJose2001
This is an outline of the basics of Pharmacology. A discussion of how drugs are named, classified and its effects on the person's biochemical processes. It also included the factors influencing drug action and potential drug interactions. At the end, some commonly ysed terminologies were defined.
Pharmacology is the branch of pharmaceutical sciences which is concerned with the study of drug or medication action, where a drug can be broadly defined as any man-made, natural, or endogenous molecule which exerts a biochemical or physiological effect on the cell, tissue, organ, or organism
Routes of drug administration - I for mbbsmani goel
No single method of drug administration is ideal for all drugs in all circumstances .A knowledge of advantages and disadvantages of different routes of administration is essential.
Pharmacokinetics (PK) is the study of how the body interacts with administered substances for the entire duration of exposure (medications for the sake of this article). This is closely related to but distinctly different from pharmacodynamics, which examines the drug’s effect on the body more closely. The four main parameters generally examined by this field include absorption, distribution, metabolism, and excretion (ADME). Wielding an understanding of these processes allows practitioners the flexibility to prescribe and administer medications that will provide the greatest benefit at the lowest risk and allow them to make adjustments as necessary, given the varied physiology and lifestyles of patients.
When a provider prescribes medication, it is with the ultimate goal of a therapeutic outcome while minimizing adverse reactions. A thorough understanding of pharmacokinetics is essential in building treatment plans involving medications. Pharmacokinetics, as a field, attempts to summarize the movement of drugs throughout the body and the actions of the body on the drug. By using the above terms, theories, and equations, practitioners can better estimate the locations and concentrations of a drug in different areas of the body.
The appropriate concentration needed to obtain the desired effect and the amount needed for a higher chance of adverse reactions is determined through laboratory testing. Using the equations given above, a clinician can easily estimate safe medication dosing over a period of time and how long it will take for a medication to leave a patient’s system. These are, however, statistically-based estimations, influenced by differences in the drug dosage form and patient pathophysiology. This is why a deep understanding of these concepts is essential in medical practice so that improvisation is possible when the clinical situation requires it.
Routes of drug administration - I for mbbsmani goel
No single method of drug administration is ideal for all drugs in all circumstances .A knowledge of advantages and disadvantages of different routes of administration is essential.
Pharmacokinetics (PK) is the study of how the body interacts with administered substances for the entire duration of exposure (medications for the sake of this article). This is closely related to but distinctly different from pharmacodynamics, which examines the drug’s effect on the body more closely. The four main parameters generally examined by this field include absorption, distribution, metabolism, and excretion (ADME). Wielding an understanding of these processes allows practitioners the flexibility to prescribe and administer medications that will provide the greatest benefit at the lowest risk and allow them to make adjustments as necessary, given the varied physiology and lifestyles of patients.
When a provider prescribes medication, it is with the ultimate goal of a therapeutic outcome while minimizing adverse reactions. A thorough understanding of pharmacokinetics is essential in building treatment plans involving medications. Pharmacokinetics, as a field, attempts to summarize the movement of drugs throughout the body and the actions of the body on the drug. By using the above terms, theories, and equations, practitioners can better estimate the locations and concentrations of a drug in different areas of the body.
The appropriate concentration needed to obtain the desired effect and the amount needed for a higher chance of adverse reactions is determined through laboratory testing. Using the equations given above, a clinician can easily estimate safe medication dosing over a period of time and how long it will take for a medication to leave a patient’s system. These are, however, statistically-based estimations, influenced by differences in the drug dosage form and patient pathophysiology. This is why a deep understanding of these concepts is essential in medical practice so that improvisation is possible when the clinical situation requires it.
GIT ABSORPTION FOR ORAL Administered DrugAli Mashwani
In this Lecture I have covered how the Drug is absorbed when it is administered orally, what is BCS classification system, Role of BCS and Importance of Biopharmaceutics Classification System. I have discussed how the Pharmakinetics process occur, what is Absorption, Distribution, Metabolism and Excretion.
This presentation includes the detail information of pharmacokinetics. How body react with drug. Route of drug administration. In this presentation there is a given all the relevant data related to the general pharmacology which is used full for the D. pharm, B. Pharm, Pharm D students . Pharmacodynamics : - What drug does to body.
Pharmacokinetics : - What body does to the drug.
Pharmacotherapeutics : - Use of drugs in prevention & treatment of disease.
Clinical pharmacology : - Scientific study of drugs in man.
Toxicology : - Aspect of pharmacology deals with adverse effects of Drugs.
Pharmacodynamic agents : - Designed to have pharmacodynamic effects in the
recipient.
Chemotherapeutic agents : - Designed to inhibit/kill parasites/malignant cells & does not have or
with minimal pharmacodynamic effects in recipient.
Orphan drugs : - Drugs or Biological Products for diagnosis/treatment/ Prevention of a
rare disease.
E.g.:- Liothyronine (T3), Desmopressin, Baclofen, Digoxin Antibody.PHARMACOKINETICS
Absorption of Drugs:-
A) Simple diffusion: - Bidirectional process rate of transfer across the membrane is proportional to
concn gradient. E.g.:- H20 soluble drugs with low mol-wt, lipid soluble drugs.
B) Active transport: - requires energy – independent of physical properties of membrane. E.g.:- H20
soluble drugs with high mol-wt.
Carrier mediated transport: - E.g.:- Intestinal absorption of Ca2+
.
C) Pinocytosis: - Important in unicellular organisms like Amoeba.
Bioavailability: - Amount of drug reaches systemic circulation following a non-vascular drug
administration.
Auc oral
F = Auc iv
Barriers:-
B.B.B:- made up of choroid cells (strong Barrier).
Testis Barrier: - made up of seroid cells.
Placental Barrier: - made up of sertoli cells (weak Barrier).
Endothelial Barrier: - in all blood cells (very weak).
For absorption of vitB12, IF factor is required which is synthesized by parietal cells?2 types of metabolism: - a. Non synthetic reaction (phase I reaction)
i. Oxidation
ii. Reduction
iii. Hydrolysis
iv. Cyclilization
v. Decyclilization
b. Synthetic reaction (Phase II reaction) conjugation reactions
i. Glucoronide conjugation
ii. Acetylation
iii. Methylation
iv. Sulfate conjugation
v. Glycine conjugation
vi. Glutathion conjugation Remember:- Many drugs are eliminated by the kidney without being.
Presentation covers the basics of pharmacokinetic. Mechanism for the transport of drug molecule. Absorption, factors affecting on absorption of drugs. Concept of bioavailability. Distribution, plasma protein binding, tissue binding, barriers.
The purpose of studying pharmacokinetics and pharmacodynamics is to understand the drug action, therapy, design, development and evaluation.
PHARMACOKINETIC: It is a branch of Pharmacology which deals with the study of Absorption, Distribution, Metabolism, Excretion / Elimination.
Pharmacokinetics is the study of “What the body does to the drug”
PHARMACODYNAMIC:
Pharmacodynamics is the study of biochemical and physiologic effect of drug. It is the study of “What the drug does to the body”
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
2. Pharmacology?
Pharmacology studies the effects of drugs and how
they exert their effects:
Acetylsalicylic acid (ASA) can reduce inflammation, pain
and fever inhibit the action of a human cell membrane
enzyme known as cyclooxygenase (COX) , which is
responsible for the synthesis of a number of inflammatory
mediators
Penicillin cures certain bacterial infections by disrupting
the synthesis of cell walls in susceptible bacterial strains
3. Pharmacology?
Pharmacokinetics
It is what the body does to the drug
How the body absorbs, distributes, metabolizes, and
excretes drugs
Pharmacodynamics
Is what the drug does to the body
Study the mechanisms by which drugs work
Clinical interactions of drugs
4. PHARMACOKINETICS
Process for a drug to reach the target organ at a
concentration sufficient to have a therapeutic effect
A successful drug should have an ability to cross
physiologic barriers that other foreign substances do not
have
This is possible through:
Drug absorption
Use of distribution systems with the body to reach the
target organ at a sufficient concentration
The drug’s ability to reach the target is limited also by:
Metabolism: enzymatic degradation
Excretion: drug eliminated from the body
9. Factors affecting absorption of
drugs
Factors related to drugs:
1. Lipid water solubility:
LWS coefficient is the ratio of dissolution of drug in lipid as
compared to water. Greater the LWS coefficient, more is the lipid
solubility of drug and greater is the absorption.
2. Molecular weight
Smaller the molecular size of drug, rapid is the absorption
3. Degree of Ionization
Different drugs are either Acid or basic and are present in ionized
or unionized form. Acid drugs are better absorbed from acid area.
4. Physical form
Drugs may exist as solids, gases and liquids.
Gases are rapidly absorbed than the liquids while liquids are
rapidly absorbed than solids
5. Formulation, particle size etc
10. Factors affecting absorption of
drugs
Factors related to the Body:
1.Area of absorptive surface:
Most of the drugs are given orally bcz of largearea of
absorptive surface,so that the greater absorption
occurs. Intestinal resection decreases the surfaces area
leading to a decreased absorption.
2.Vascularity:
More the vascularity, more is the rate of absorption.
3. pH:
Acidic pH favors acidic drugs absorption while basic pH
is better for basic drugs.
4. Presence of other substances:
Eg: Vit C enhances the absorption of Iron
11. Factors affecting absorption of
drugs
5. GI mobility
6. Functional integrity of absorptive surface: edema
7.Diseases: Diarrhea, malabsorptive sd etc
12. Absorption
Biological membranes:
All human cells are limited by a lipid bilayer
membrane→ passive diffusion +++ for non polar
small molecules
Facilitated diffusion: Transmembrane carrier proteins
for bigger molecules
Active transport: needs energy
Endocytosis: some drugs bind to specific cells and form
vesicles form which drugs are released into the cell
13. Absorption
Central Nervous System:
Well insulated from foreign substances
Blood-brain barrier: tight junctions prevent passive
diffusion
Drugs acting into in the CNS:
Sufficiently small and hydrophobic to cross the mbne
or use existing transport proteins in the BBB
BBB bypassed using intrathecal drug infusion
14. Absorption
BIOAVAILABILITY
The fraction of administered drug that reaches
the systemic circulation
Depends on:
Route of administration
Chemical form of drug
Patient’s specific factors (eg: GI and hepatic
transporters and enzymes)
15. ABSORPTION
Bioavailability
The fraction of the dose of a drug (F) that enters
the general circulatory system,
F= Amount of drug that enters systemic circulation
Dose administered
F = AUC/Dose
18. ABSORPTION
Different routes of administration of drugs
Enteral: weak barriers, but acid (gastric) and basic
(duodenal) can ↓bioavailability, easy, no risk of
bloodsteram infection
First pass hepatic metabolism: ↓bioavailability
Parenteral (IV, IM, SC, IT): rapid delivery, pain, infection,
irreversible
For IV drugs: bioavailability = 1.0
Mucous membrane: rapid delivery, no first pass, low
infection, direct delivery to affected tissue
Transdermal: simple, painless, excellent for continuous
administration. Requires highly lipophilic drug, may be
irritating
19. ABSORPTION
Clinical example of FIRST PASS Metabolism :
Morphine
Undergoes extensive first pass metabolism
Oral bioavailability is 30 – 50 %
Oral dose not comparable with IV dose
20. Distribution
1. Definition:
Distribution is the process of delivering a drug from the
bloodstream to the tissues of the body
It is a reversible transfer of drug between one
compartment (blood) to another (extra vascular tissue)
Plasma concentration: poor measure of tissue
concentration
Distribution affects the duration of action of the drug
21. Distribution
2. Significance:
Pharmacological action of drug depends upon its
concentration at the site of action
Thus distribution plays important role in:
Onset of Action
Intensity of Action
Duration of Action
24. FACTORS AFFECTING DISTRIBUTION OF
DRUGS
1. Tissue Permeability of Drugs
Physicochemical Properties of drug like:
• Mol.size, pKa, o/w Partition Coefficient
Physiological barriers to diffusion of drugs
• Simple Capillary Endothelial Barrier
• Simple Cell Membrane Barrier
• Blood Brain Barrier
• Blood-CSF Barrier
• Blood Placental Barrier
• Blood Testis Barrier
2. Organ/tissue size and perfusion rate
3. Binding of drugs to tissue components.
binding of drug to blood components
binding of drug to extra cellular components
25. FACTORS AFFECTING DISTRIBUTION OF
DRUGS
4. Miscellaneous:
Age:
Total body water
Fat content
Skeletal muscles
Organ composition
Plasma protein content
Pregnancy
Obesity
Diet
Disease states
26. METABOLISM
Definition
Chemical alteration of drug in the body.
Non polar lipid soluble compounds are made polar lipid
insoluble, so that they are easily excreted.
SITES
Primary site – Liver
Others – Kidney, Intestine, Lungs, Plasma
27. METABOLISM
Drug Biotransformation : convert lipophilic /
hydrophobic drug (to enter cells) to hydrophilic
metabolites.
Advantages
Termination of drug action - (↓ toxicity)
Reduced lipophilicity.
Renal / biliary excretion ↑ - (↓renal reabs)
29. METABOLISM
CONSEQUENCES
A) Drug inactivation - inactive or less active
Propranolol,Pentobarbitone,Morphine,Chloramphenicol,Parac
etamol,Ibuprofen,lignocaine
B) Active drug to Active metabolite- Active metabolite
Effect is due to parent drug and its active metabolite
C) Inactive drug (Prodrug) - Active drug
Prodrugs are inactive drugs which need BT in the body to form
active metabolites.
ADV
More stable
Better BA
Less toxicity
Eg: Levodopa - Dopamine
Enalapril - Enalaprilat
30. METABOLISM
TYPES
Biotransformation reactions - 2 types
Phase I / Non synthetic / Functionalization
A functional group is generated
Metabolite – active or inactive
Phase II / Synthetic / Conjugation
An endogenous radical is conjugated
Metabolite is usually inactive
32. INHIBITION OF DRUG
METABOLISM
One drug can inhibit the metabolism of another drug
↑ in circulating levels of slowly metabolized drug
Prolongation or potentiation of its effects
Consequences
Precipitate toxicity of the object drug.
can be therapeutically beneficial. Eg: aversion of
alcohol with disulfiram, Reversal of SKM paralysis
of d-tc by neostigmine
e.g:Valproate,Ketoconazole,Cimetidine,Ciprofloxacin,Er
ythromycin,INH
Code – Vitamin K cannot cause enzyme inhibition.
33. MICROSOMAL ENZYME
INDUCTION
Inducers of enzymes that mediate the phase I
reaction enzymes (eg: Barbiturates)
Drugs, insecticides, carcinogens will induce the
synthesis of microsomal enzyme proteins
Accelerated metabolism and reduced
pharmacological response
Consequences
Drug- drug interactions
Can lead to toxicity. Eg: Alcoholics more prone to
hepatotoxicity of paracetamol due to↑ production of
NABQI
Decreased duration of action.
EG:Griseofulvin,Phenytoin,Rifampicin,Smoking,Carbam
34. First Pass Metabolism
Presystemic metabolism/ First pass effect
Metabolism of a drug during its passage from the site
of absorption into the systemic circulation.
↓BA
↓therapeutic response
SITES
Gut wall
Gut lumen
Liver (major site)
Lungs
Skin
35. Attributes of drugs with FPM
Oral dose is higher than sublingual or parenteral.
Oral BA is increased in patents with severe liver
disease.
Drugs with FPM usually have short plasma t1/2.
Oral BA is increased if another drug competing
with it in first pass metabolism is given
concurrently. Eg: CPZ & Propranolol
36. ELIMINATION
Clearance
Factor that predicts the rate of elimination in
relation to the drug concentration
Rate of elimination = CL x C
CLsystemic = CLliver + CLkidney + CLother
Rate of elimination
Plasma concentration (C)
Clearance (CL) =
37.
38. ELIMINATION
Effect of disease processes
Disease processes can alter the elimination of a
drug:
Hepatic failure
Renal failure
40. RENAL EXCRETION:
• Most important organ for Elimination.
• Free drugs (eg. Furosemide,gentamicin)
• Drug Metabolites
PROCESSES THAT DETERMINE RENAL
– Glomerular filtration.
– Active tubular Secretion.
– Passive tubular reabsorption.
FACTORS OF GLOMERULAR FILTRATION:
• Molecular size.
• Plasma protein binding
• Renal Blood Flow
41. BILIARY EXCRETION & ENTEROHEPATIC
CIRCULATION:
• Drugs excreted in Bile:-Quinine,
Colchicines, Corticosteroids.
• Some drugs secreted through bile but after
being delivered to intestine, are
reabsorbed back and the cycle is
repeated. Eg: Digitoxin.
• Other drugs with enterohepatic circulation:
• Morphine, Chloramphenicol, Tetracycline
etc.
42. ALVEOLAR EXCRETION:
• Gases & Volatile liquids eg: General
Anaesthetics, Ether, Alcohol
• Depends on partial pressure in the blood.
• Eucalyptus oil and garlic oil eliminated
through expectoration.
43. ELIMINATION THROUGH BREAST
MILK:
• May cause unwanted effect in Nursing
infant.
• Drugs transferred to breast milk according
to pH partition principle.
• Basic drugs not ionised at plasma alkaline
pH, get accumulated in Milk. Eg:
Chloramphenicol, Tetracycline, Morphine
etc.
44. Half-Life
It is defined as the time required for drug blood levels
to be reduced by 50%.
Factors affecting half-life
Decreased:
Ageing (decreased muscle and off course Vd)
P450 induction
Increased:
Obesity ( adipose tissue and Vd)
P450 inhibition
Cardiac failure
Hepatic failure
Renal failure
45. PHARMACODYNAMICS
Pharmacodynamics is the study of drug effects.
Wanted effects of drugs
Side effects
Clinical Interactions with other drugs:
Synergy
Antagonism
Addition
46. Pharmacodynamics
Drug-receptor interactions
2 properties determine the nature of a drugs
pharmacological effect:
Affinity
Refers to how well a drug binds to its receptor
Intrinsic activity or efficacy
refers to the magnitude of effect the drug has once bound to the
receptor
47. PHARMACODYNAMICS
Definitions
Agonist: Mimic actions of neurotransmitter at same
site
Affinity for receptor
Intrinsic activity
Antagonist: Block actions of neurotransmitter at
same site
Affinity for receptor
NO intrinsic activity
48. PHARMACODYNAMICS
Agonists
Full agonist
Drug that generates a maximal response from a
receptor (Emax)
Demonstrates high affinity & high intrinsic activity
Partial agonist
Fails to achieve maximal effect even in high dose
Demonstrates reduced intrinsic activity
50. PHARMACODYNAMICS
Antagonists
Reversible
Competitive
The effect of the antagonist can be overcome by increasing the
concentration of the agonist
The 2 molecules are competing for the same receptor
Non-competitive
Do not bind to the same site on the receptor as the agonist
Effect results from preventing receptor activation through
conformational distortion
Effect cannot be overcome by increasing the concentration of
agonist
Irreversible
Irreversibly bind to the receptor
Increasing agonist concentration will not overcome the blockade
53. Drug potency and efficacy
Drug potency which refers to the amount of
drug needed to produce a certain response.
Drug efficacy refers to the maximal response
that can be elicited by the drug.
54. Drug potency and efficacy
Drug B is less potent but
equally efficacious as drug A.
Drug C is less potent and
less efficacious than drug A.
Drug D is more potent than
drugs A, B, & C, but less
efficacious than drugs
A & B, and equally
efficacious as drug C.
56. Combined effect of Drugs
Synergism:
When the action of one drug is facilitated or increased by
the other, they are said to be synergistic.
Additive Synergism
The effect of the two drugs is in the same direction and
simply adds up:
Effect of drugs A + B = effect of drug A + effect of drug
B.
Absorption: refers to movement of a drug from site of administration to bloodstream
Ionisation: pKa = pH at which 50% of drug molecules are ionized (charged)
Only uncharged molecules are lipid soluble.
The pKa of a molecule influences its rate of absorption through tissues into the bloodstream.
pH varies among tissue sites
e.g., stomach: 3-4, intestines: 8-9
Acid drugs are unionized in acidic medium
Passive diffusion: movement of sbtce from an erea of higher concentration to an erea of lower concentration.
Facilitated diffusion: movement from higher to lower concentration using a carrier protein in the cell
The CNS presents special challenges to the pharmacologic therapy
This diagram shows the evolution of the concentration of the drug in the blood/body after its absorption from the site (route) of administration.
first pass metabolism: it is the fraction of drug lost during the processs of absorption which is generally related to the liver and gut
.
Bulk flow : it refers to the transport of fluids or electrolytes between cells through openings, or pores between cells
Age: Difference in distribution pattern is mainly due to Total body water -(both ICF &ECF) greater in infants, Fat content - higher in infants & elderly, Skeletal muscle - lesser in infants & elderly.
PREGNANCY:
During Pregnancy, due to growth of UTERUS,PLECENTA,FETUS…Increases the volume available for distribution drug
OBECITY :
In obese persons, high adipose (fatty acid) tissue so high distribution of lipophilic drugs
Tachyphylaxis: it is a rapid diminishing response to successive doses of a drug,rendering it less effective.