Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

MN553 / MN553: Advanced Pharmacology & Pharmacotherapeutics Unit 2 Quiz Study Guide, Study Guides, Projects, Research of Nursing

MN553 / MN553: Advanced Pharmacology & Pharmacotherapeutics Unit 2 Quiz Study Guide (Latest, 2022/2023)

Typology: Study Guides, Projects, Research

2021/2022

Available from 02/15/2022

Experttutor1
Experttutor1 🇬🇧

3.8

(96)

906 documents

1 / 9

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
MN553 Advanced Pharmacology & Pharmacotherapeutics Unit 2 Quiz Study Guide
Describe the absorption, distribution, metabolism, and elimination process
of drugs in the body.
Absorption: entering the body
Parenteral Administration (IV): straight to the bloodstream, but once
administered, the drug absorption cannot be slowed, and the drug
cannot be removed from the body
Oral: common and most convenient route, keep in mind pH and where
the drug needs to take effect (stomach, intestines, etc.)
Site of administration: eyes, ears, throat/lungs, skin
Bioavailability: Not all of the administered dose may be dissolved,
absorbed, or survive liver metabolism, only a fraction of an administered
dose makes it to the bloodstream. 100% bioavailability for IV, 10-90% for
oral.
Peak Blood Levels: Rapid absorption leads to higher peak blood levels,
with a risk of greater toxicity and side effects. Some drugs (like
aminoglycoside antibiotics) need to be closely monitored for toxicity.
Distribution: process of drug moving through the body
Properties that affect distribution: drug size, charge, chemical structure,
pH, molecular size, lipid or water solubility.
HendersonHasselbalch Relationship: the effects of pH and ion
charge/concentration affecting how drugs pass through cell membranes
Protein binding: the biggest player is albumin.
Other proteins: alpha-1-acid glycoprotein, cortisol-binding globulin, sex
hormonebinding globulin, and lipoproteins.
General principle that drug action occurs through free, unbound drug.
Protein binding, which may include binding to proteins that are not in the
plasma, also prevents the interaction of drug molecules with their site of
action. Plasma protein binding creates a reservoir of bound drug
molecules that can dissociate at any time to interact with drug receptors
and produce responses.
Transport system: membrane proteins that actively move drugs in and out
of the cell.
Volume of Distribution: the concentration of a drug can vary depending
on where it “sits” in the body’s fluids (plasma, extracellular fluid or
intracellular fluid).
Metabolism: the chemical alteration of the drugs into metabolites.
Metabolism of drugs can occur in every biological tissue, but it occurs
mostly in the smooth endoplasmic reticulum of cells in the liver.
pf3
pf4
pf5
pf8
pf9

Partial preview of the text

Download MN553 / MN553: Advanced Pharmacology & Pharmacotherapeutics Unit 2 Quiz Study Guide and more Study Guides, Projects, Research Nursing in PDF only on Docsity!

MN553 Advanced Pharmacology & Pharmacotherapeutics Unit 2 Quiz Study Guide

  • Describe the absorption, distribution, metabolism, and elimination process of drugs in the body. - Absorption: entering the body - Parenteral Administration (IV): straight to the bloodstream, but once administered, the drug absorption cannot be slowed, and the drug cannot be removed from the body - Oral: common and most convenient route, keep in mind pH and where the drug needs to take effect (stomach, intestines, etc.) - Site of administration: eyes, ears, throat/lungs, skin - Bioavailability: Not all of the administered dose may be dissolved, absorbed, or survive liver metabolism, only a fraction of an administered dose makes it to the bloodstream. 100% bioavailability for IV, 10 - 90% for oral. - Peak Blood Levels: Rapid absorption leads to higher peak blood levels, with a risk of greater toxicity and side effects. Some drugs (like aminoglycoside antibiotics) need to be closely monitored for toxicity. - Distribution: process of drug moving through the body - Properties that affect distribution: drug size, charge, chemical structure, pH, molecular size, lipid or water solubility. - Henderson–Hasselbalch Relationship: the effects of pH and ion charge/concentration affecting how drugs pass through cell membranes - Protein binding: the biggest player is albumin. - Other proteins: alpha- 1 - acid glycoprotein, cortisol-binding globulin, sex hormone–binding globulin, and lipoproteins. - General principle that drug action occurs through free, unbound drug. Protein binding, which may include binding to proteins that are not in the plasma, also prevents the interaction of drug molecules with their site of action. Plasma protein binding creates a reservoir of bound drug molecules that can dissociate at any time to interact with drug receptors and produce responses. - Transport system: membrane proteins that actively move drugs in and out of the cell. - Volume of Distribution: the concentration of a drug can vary depending on where it “sits” in the body’s fluids (plasma, extracellular fluid or intracellular fluid). - Metabolism: the chemical alteration of the drugs into metabolites. - Metabolism of drugs can occur in every biological tissue, but it occurs mostly in the smooth endoplasmic reticulum of cells in the liver.
  • Metabolism by the liver following oral administration is called first-pass metabolism and is important in determining whether a drug can be orally administered.
  • Phase I reactions, called non-synthetic reactions , involve oxidation, reduction, and hydrolysis reactions, which prepare the drug molecule for further metabolism. (Making the drug more water soluble).
  • Phase II reactions are called synthetic or conjugation reactions because drug molecules are metabolized, and something is added to the drug to synthesize a new compound. Conjugation to these molecules makes metabolites more water soluble and more easily excreted by the kidneys.
  • Major player CYP P450: catalyzes the metabolism of a large number of diverse, highly lipid-soluble drugs and chemicals. CYPs transfer electrons from the oxidation of drugs to the electron transport system of the endoplasmic reticulum, a cell organelle.
  • Single nucleotide polymorphisms (SNPs) are minor mutations in proteins that can result in metabolic activity changes. These alterations in DNA are sometimes associated with population groups and help explain why certain groups of patients are more or less sensitive to certain drugs.
  • Drug interactions: some chemicals, foods or drugs can compete, block, limit, or increase/decrease drug receptor function. (it’s an Affinity War! Get it? Avengers movie.) Drugs that have a higher affinity will block or be processed first.
  • Excretion: drugs are transferred from inside the body to outside the body
  • kidney is the primary organ of excretion for most drugs
  • The renal system filters the body’s fluid via the glomerulus in the nephrons. Controls electrolyte and fluid balance.
  • Other points of excretion: liver, pulmonary, skin, sweat, saliva, hair, and breast
  • Discuss the process of a drug reaching steady state concentration in the body.
  • Apply the principles of pharmacokinetics to the elderly, pediatrics, and pregnant/nursing women.
  • Pediatric: ◆ Absorption
  • More than in adults; 1 Blood flow at the site of administration (IM) or (SC) ▪ 1 st^6 months = increased perfusion to muscles - HOWEVER – decrease flow during illness = delayed or variable absorption 2 GI function
  • Carbamazepine
  • Clarithromycin +++ ▪ Foods affected by CYP1A2;
  • Grapefruit juice
  • Cruciferous veggies
  • Char-broiled foods ▪ Smoking; may affect drugs, esp. anti-seizure meds ▪ SO, drug doses need to be adjusted; higher to puberty, and monitored through puberty ▪ CYP2D6 is absent or 5% active @ birth – reaches full adult activity between 3 - 5 years BUT has significant genetic variability;
  • Up to 20% of Ethiopians are 2D6 ultrametabolizers BUT 3.4% - 6.5% of non-Ethiopian Africans are ultrametabolizers; same for Caucasians
  • Ultrametabolizers metabolize codeine at a greater rate – leading to elevated morphine levels (CAREFUL giving Codeine to kids
  • 5 - 10% of Caucasians & 1 - 2% of Asians Are POOR 2D6 metabolizers; SSRIs and others inhibit 2D6, leading to prolonged half-life, so small doses not tolerated
  • Antiseizure meds – carbamepazine topiramate & lamotrigine MONITOR
  • CYP3A4 follows similar development; exceeds adult levels until puberty
  • Metabolize 20+ common peds medications ◆ Carbamazepine ◆ Prednisone ◆ Oral contraceptives ◆ Macrolides ◆ NSAIDs ◆ Antihistamines = others
  • NOTE; in general the small intestine is major sire of drug metab due to CYP450 enzymes & may be a large variation in capacity of SB to metabolize drugs 2. Phase II Enzymes (water soluble synthesis)Less information on phase II for kids ▪ UGT 2B7; morphine – clearance in FT infants and kids adult levels @ 2 - 6 months ▪ Ethnic variations in TPMT (Koreans) ▪ Acetaminophen, morphine, propofol & caffeine metabolized via Phase II
  • Careful monitoring
  • Lower rate of clearance in kids (based on weight) ♦ Excretion ▪ Affected by GFR in newborns; 30 - 40% of adult values)
  • Ampicillin, aminoglycoside abx & digoxin
  • Reach adult levels ~ 9 mos.
  • Women and Pregnant Women: o Women have longer gastric emptying times, which influence the absorption and bioavailability of some drugs o The volume of distribution (Vd) of drugs is dramatically altered by body composition. ▪ The higher percentage of body fat means a larger Vd for lipophilic agents o women experience more adverse reactions after the drug saturates all the sites in adipose tissues and more active drug remains in the bloodstream. o Gastric levels of alcohol dehydrogenase are lower in women, so a greater fraction of ingested alcohol would be oxidized in men before absorption than in women. ▪ This is a significant factor behind why blood alcohol levels are disproportionately higher in women after ingestion of similar amounts of alcohol. o While hepatic blood flow is lower in women, differences in hepatic enzymes seem to be the major factor in variability – gender-based difference in drug metabolism (CYP450 system). o Studies have shown that CYP3A4 activity is 24% higher in women and CYP1A2 is lower ▪ CYP3A4 – group of isoenzymes responsible for drug metabolism
  • Examples of drug classes: - azole antifungals, calcium channel blockers, antihistamines, anticonvulsants, antimicrobials, and corticosteroids. ▪ CYP1A2 – an enzyme responsible for metabolizing many drugs
  • Examole: theophylline o Cruciferous foods like broccoli, cabbage induce drugs metabolized by CYP1A o Apiaceous vegetables like carrots, parsnips, celery, or parsley family inhibit CYP1A2 activity o Propranolol (Inderal) was one of the earliest drugs to show a clear gender difference in metabolic clearance of a drug. ▪ Oral doses of this drug had a significantly higher (63%) rate of clearance in men than it did in women ▪ IV doses demonstrated no differences, indicating that this was a hepatic first-pass metabolism issue. ▪ Women might show a significantly greater clinical response to oral doses of this drug than men. o The gender-related difference in CYP2D6 activity and P-glycoprotein expression may be an important reason for different responses to antidepressants such as selective serotonin reuptake inhibitors

- D/t Cerbrovascular Pgp activity being reduced, greater penetration of drugs in the CNS and expose brain to elevated levels of some drugs and toxins. o Metabolism: Most drug metabolism occurs in liver. Drug clearance in liver depends on hepatic blood flow and enzyme activity. Age causes decrease in liver size, blood flow, and metabolism. - More pronounced in malnourished frail elders Propranolol, verapamil, and diazepam undergoes extensive first pass metabolism (P450) sometimes poorly tolerated by older adults. Decreased hepatic clearance can result in significant increase in the bioavailability and half-life of drugs, d/t relying on high rates of blood flow through the liver for extraction. o Excretion: Most drugs are eliminated through the kidneys. Dosing guidelines available to help providers make appropriate adjustments for renal impairment. Serum Creatinine most reliable to determine kidney function. Not reliable in older adults malnutrition can affect this test. BUN requires adequate protein ingestion.

  • Discuss the principles of pharmacogenomics. o Involves the influence of both race/ethnicity and individually makeup on drug mechanisms
  • Pharmacogenetics: study of the influence of heredity factors on the response of the individual organism to drugs
  • Pharmacogenomics: study of the effects of genetic differences among people that the impact of genetic differences among people and the impact that these differences have on the uptake effectiveness toxicity and metabolism of drugs
  • Goal of pharmacogenomics ▪ Prediction models to forecast debilitating adverse events in individuals and across populations based on similarities in age gender and race and ethnicity ▪ Prediction of deviation of patients from pharmacokinetic and thermodynamic responses o Idiosyncratic response
  • Identify patterns of genetic variations to guide the design of medical regimens for individual patients
  • By using the patient’s DNA sequence, it could enhance drug therapy to maximize efficacy, target medications to only those who will respond, and avoid ADRs
  • Inherited differences in metabolism and disposition of drugs can influence the efficacy and toxicity of medications
  • Genotype: is a combination of individuals parents genes
  • Genome: genes and chromosomes
  • Polymorphic gene: allelic variations occur through the population at a stable rate less than 1%
  • Mutant genes will exist and create the production of mutant proteins o Mutant proteins interact with drugs
  • Four phenotypes: categorize the effects that genetic polymorphins have on the individual ▪ Poor metabolizers (metabolizes drugs slow) - Lack a working enzyme - Accumulation of active drug ▪ Intermittent metabolizers - Heterogeneous of one working ▪ Extensive metabolizers - Two normal functioning alleles ▪ Ultrarapid metabolizers (metabolizes drugs fast) - Have more than one functioning copy of a certain enzyme - Could lead to drug failure due to how fast it Is metabolizing
  • Drug metabolism takes place mostly in the liver and is divided into two phases: ▪ Phase I: oxidation, reduction, and hydrolysis reactions - Responsible for 59% ADRs - CYP enzymes help break down drugs ▪ Phase II: conjugation reactions
  • CYP450 enzymes ▪ 19% of drugs are metabolized by CYP2D ▪ Metabolizes beta blockers, antidepressants, antipsychotics ▪ 35% of population has a nonfunctional 2D6 allele which could increase the risk of ADRs ▪ Part of the population has a duplicate of 2D6 which could lead to ultrarapid metabolism and increase the risk of drug therapy failure ▪ CYP2D6 and Tamoxifen - Activates it rather than helping with metabolism ▪ CYP2D6 and Opioid Analgesics (Codeine) - CYP2D6 helps convert codeine to their active form, morphine. o Ultrarapid metabolizers: may not experience the analgesic effects ▪ If a breastfeeding mother is an ultra-rapid metabolizer, codeine can be transfer to the baby via breastmilk and cause CNS effects