How does hypoalbuminemia affect the process of prescribing?
is considered a contraindication to administer that drug.
According to the WHO what is the first step in the prescribing process?
The first step is to define the patient’s problem
specify the therapeutic objective
choose which drug or treatment is needed.
The drug is tested on healthy volunteers
trials with people who have the disease for which the drug is thought to be effective
This phase is voluntary and involves postmarket surveillance of the drug’s therapeutic effects at the completion of phase 3. The pharmaceutical company receives reports from doctors and other health care professionals about the therapeutic results and adverse effects of the drug. Some medications, for example, have been found to be toxic and have been removed from the market after their initial release.
What is the fasted route of absorption:
Why does the GI tract take longer to absorb?
What is One particular cellular barrier that may prevent absorption of a given drug?
Why does absorption occur at a slower rate for oral, IM, SQ routes?
The ability of a drug to cross a cell membrane depends on:
As a drug travels through the body, it comes in contact with?
proteins such as the plasma protein albumin. The drug can remain free or bind to the protein. The portion of a drug that’s bound to a protein is inactive and can’t exert a therapeutic effect. Only the free, or unbound, portion remains active. A drug is said to be highly protein-bound if more than 80% of the drug is bound to protein.
Identify drug metabolism and the role of isoenzymes in the p450 system
Naturally occurring compounds may induce or inhibit CYP activity.
What does grapefruit have to do with CYP?
Grapefruit is an inhibitor and will decrease the metabolism of drugs by the cyp enzymes
When 2 drugs are both metabolized by the p450 system the drug should be
What is the efficacy of a drug?
On the drug concentration curve what is the first sign of a therapeutic effect?
What is the purpose of a peak and trough level?
To determine if the drug is in therapeutic range.
Describe the purpose of blood brain barrier
The BBB is a highly selective permeability barrier that separates the circulating blood from the brain and extracellular fluid in the CNS. The BBB is formed by brain endothelial cells which are connected by tight junctions with an extremely high electrical resistivity of at least 0.1 micron. The BBB allows the passage of water, some gases, and lipid soluble molecules by passive diffusion as well as the selective transport molecules such as glucose and amino acids that are crucial to neuro function.
Describe the purpose of the fetal placental barrier
the so-called placental barrier impedes certain chemicals although it allows most fat soluble chemicals to cross. Drugs that are more water soluble and that possess a higher molecular weight tend not to cross the placental barrier. In addition, if a drug binds to a large molecule, such as a blood-borne protein like albumin, it is even less likely to come into contact with fetus.
How will renal insufficiency affect drug elimination?
The kidney is the primary organ of excretion for most drugs. General theme of metabolism is to produce drug metabolites that are more water soluble and more easily removed by the kidneys. The rate at which the drug is excreted by the kidneys depends on several factors. Renal blood flow influences the glomerular filtration rate (GFR) which is how much plasma is filtered per minute by the glomerulus.
Renal excretion of drugs is typically well-characterized, what is variable is the
level of renal function the patient.
Patients with poor renal function may have higher levels of drugs secondary to
decreased excretion of metabolites.
What is off-label prescribing?
What factors place an infant and child at risk when prescribing medication?
In general, there is a lack of safety and efficacy studies in the pediatric population most medications are studied in adult populations which because of age-related differences and medication metabolism and mechanisms of action don’t necessarily apply to pediatric populations. Children are not just small adults. Adverse drug reactions are most common in this age group. Kids do not have a fully mature liver and renal function, and are at higher risk for toxicity and adverse drug effects.
What ADRs are the elderly at risk of developing?
In the elderly, Hepatic blood flow decreases by
nearly one-half or 40% in older adults.
some degree of chronic kidney disease is present in X of older adult
Heart failure, which affects more than forty percent of persons older than 80 years, can
further reduce the function of the aging kidneys and liver.
Other factors influence pharmacokinetics in older adults include
aging decreases first-pass clearance in the liver, and a number of commonly prescribed medications like warfarin, benzos, and opiates require much lower doses in older adults. Distribution of drugs to body compartments has changed by the decrease in the ratio of lean body weight to body fat. Levels of serum protein, which bind many drugs, decrease in older adults because of malnutrition and dietary changes that are common for both intentional and unintentional regions. Drug metabolism can be affected by substance abuse including alcohol, up to ten percent of older adults are heavy or problem drinkers. Polypharmacy.
What are the adverse drug reactions related to special populations?
Type 1 hypersensitivity or immediate hypersensitivity is an
In type 2 hypersensitivity or cytotoxic hypersensitivity,
An example of type 2 hypersensitivity is the
ABO blood incompatibility where the red blood cells have different antigens causing them to be recognized different. B-cell proliferation will take place in antibodies until foreign blood types are produced. IgG and IgM antibodies bind to these antigens to form complexes that activate the classical pathway of the complement activation to eliminate cells presenting foreign antigens. that is mediators of acute inflammation are generated at the site and the membrane attack of complexes cause cell lysis and death. This reaction takes between hours to a day.
Type-3 hypersensitivity occurs when
there is an accumulation of immune complexes or antigen-antibody complexes that may not have been adequately cleared by innate immune cells, giving rise to an inflammatory response and attraction of leukocytes. Such reactions progress into the point of disease producing immune-complex diseases. The reaction can take hours, days, or even weeks to develop depending on whether or not there is immunologic memory of the precipitating antigen. Typically, clinical features emerged a week following initial antigen challenge from the deposited immune complexes that can precipitate the inflammatory response. Type 4 hypersensitivity is often called delayed-type hypersensitivity, as a reaction take 2-3 days to develop. unlike other types it is not antibody-mediated but rather cell mediated response.
Which medications interact with St. John’s Wort?
Which medications interact with St. John’s Wort?
St. John’s Wort is a medicinal herb with antidepressant activity and potent anti-inflammatory properties. St. John’s wort has interactions with medications such as SSRI antidepressants, warfarin, and birth control. Combining St. John’s Wort and SSRI antidepressants, could lead to an increased serotonin level causing serotonin syndrome. Combining estrogen containing oral contraceptives with St. John’s Wort can lead to a decreased efficacy of the contraceptive and eventually unplanned pregnancies. It is also known to decrease the efficacy of HIV medications, cholesterol medications, as well as transplant medications. It should be noted however that traditional SSRI antidepressants such as fluoxetine carry similar contraindications. Use nonjudgmental approach so they tell u what herbs they take. Tricyclics and SJW can increase the risk for serotonin syndrome.
It is an alpha-1 adrenergic receptor blocker that inhibits the binding of norepinephrine released from sympathetic nerve terminals to the alpha 1 receptors in the membrane of vascular smooth muscle cells. the primary effect of this inhibition is relaxed vascular smooth muscle tone or vasodilation, which decreases peripheral vascular resistance leading to decrease blood pressure. is used to treat high blood pressure and urinary retention associated with benign prostatic hyperplasia (BPH). Doxazosin also shows potential for treatment of benign prostatic hyperplasia and erectile dysfunction. Doxazosin has shown some efficacy in in treating chronic epididymitis. Adverse effects include orthostatic hypotension and reflex tachycardia.
Alpha blockers end in “zosin” are mostly used for
What is the action of effective beta-blockers?
Betablockers – first choice for HTN?
They have been used in hypertension but no longer our treatment of first choice
Beta-blockers block the action of
The three types of beta receptors what are they?
They are known designated beta-1, beta-2, and beta-3 receptors.
Beta-1 adrenergic receptors are located mainly in the
lungs, GI tract, liver, uterus, vascular smooth muscle and skeletal muscle.
Beta-3 adrenergic receptors are located in
Beta receptors are found on cells of the
chronotropy, inotropy, dromotropy, renin release and lypolysis.
There are two types of beta-blockers;
there are non-selective agents, adn selective agents
Beta 1 selective agents, also known as cardio selective, they have
Beta-adrenergic blockers, the most widely used adrenergic blockers, work by:
Pharmacokinetics of Beta-adrenergic blockers
they are usually absorbed rapidly and well from the GI tract and are somewhat protein-bound. Food doesn’t inhibit—and may even enhance—their absorption. Some betaadrenergic blockers are absorbed more completely than others. Beta-adrenergic blockers have widespread effects in the body because they produce their blocking action not only at adrenergic nerve endings but also in the adrenal medulla.
What are the adverse effects of beta-blockers? (16)
hypotension, bradycardia, peripheral vascular insufficiency, atrioventricular block, heart failure, fatigue, bronchospasm, diarrhea or constipation, nausea and vomiting, abdominal discomfort, anorexia, flatulence, rash, fever with sore throat, spasm of the lower neck, respiratory distress as an allergic response.
Adverse effects associated with beta-2 adrenergic receptor antagonists’ activity will include
Beta blockade especially the beta 1 receptor at the macula densa inhibits
renin release thus decreasing the release of aldosterone this cause hyponatremia and hyperkalemia.
Beta 1 selected blockers can increase
In general, beta blockers should be avoided in
Beta blockers are also contraindicated in patients with
Beta-blockers should be avoided in patients with a history of
cocaine use or cocaine induced tachycardia.
adverse drug reactions associated with use of beta-blockers include (22)
nausea, diarrhea, bronchospasm, dyspnea, cold extremities, exacerbation of Raynaud’s, syndrome, bradycardia, hypotension, heart failure, heart block, fatigue, dizziness, alopecia, abnormal vision, hallucinations, insomnia, nightmares, sexual dysfunction, erectile dysfunction, and or alteration of glucose and lipid metabolism
What effect will result with rapid withdrawal of a beta-blocker?
DO NOT MISS ANY DOSES, high rick of stroke due to HTN if stopped abruptly.
Clonidine treats high blood pressure by stimulating alpha 2 receptors in the brain, which decrease peripheral vascular resistance lowering blood pressure. The risk of rebound hypertension is increased in alpha agonist, so it’s important that you do not miss any doses. Usually used when others are not controlling. If stopped can result in rebound HTN urgency, concern for CVA
What are the adverse effects of a beta 1 selective blocker?
Serious side effects that are advised to be reported immediately include symptoms of bradycardia, which is a resting heart rates lower than 60 beats per minute, symptoms of dizziness, fainting, and unusual fatigue, bluish discoloration of the fingers and toes, numbness tingling swelling of the hands and feet, sexual dysfunction, erectile dysfunction, hair loss, mental or mood changes, depression, trouble breathing, cough, dyslipidemia, and increased thirst.
What is a cholinergic blockers?
What effect is produced of cholinergic blockers?
Anticholinergics inhibit parasympathetic nerve impulses by selectively blocking the binding of neurotransmitter acetylcholine to its receptor and nerve cells. The nerve fibers in the parasympathetic system are responsible for the involuntary movement of smooth muscles present in the GI tract, urinary tract, and lungs.
Anticholinergic drugs are used to treat a variety of conditions, such as
GI disorders like gastritis, diarrhea, pylorospasm, diverticulitis, ulcerative colitis, nausea and vomiting; genitourinary disorders cystitis, urethritis, prostatitis; respiratory disorders like asthma, chronic bronchitis, COPD, sinus bradycardia due to hypersensitive vagus nerve, insomnia although usually only for a short term basis, dizziness including vertigo, motion sickness related symptoms.
Anticholinergics side effects:
decrease saliva production and most produce some level of sedation, both being advantageous for surgery procedures. For many of these effects cholinergic analogues produce the opposite effect so it would be helpful for you to go through and note make another chart with the cholinergic receptors and what happens when you block them and you simulate them and all the different organ systems.
Cholinergic blockers are often used to treat
GI disorders and complications.
All cholinergic blockers are used to treat
spastic or hyperactive conditions of the GI and urinary tracts because they relax muscles and decrease GI secretions. These drugs may be used to relax the bladder and to treat urinary incontinence. The quaternary ammonium and amine compounds such as propantheline are the drugs of choice for these conditions because they cause fewer adverse reactions than belladonna alkaloids. •
What are Belladonna alkaloids?
This is used with morphine to treat biliary colic (pain caused by stones in the bile duct). •
Who gives the ARNP authority to practice and prescribe medications?
It’s the state board of nursing in your respective state
Carvedilol is what type of blocker and what is its brand name?
alpha and beta blockers which is sold in the brand name Coreg,
It primarily works by vasodilation of the peripheral vasculature, thereby decreasing the workload of the heart. It is a non-selective beta-blocker and also an alpha 1 blocker, belongs to the third generation of beta-blockers. It is particularly useful in African Americans. The starting dose is 6.25 to 25 milligrams, by mouth, twice a day, and should be administered with food to prevent postural hypertension.
What race does Coreg work best for?
What are anticholinergic drugs used for?
How many half lives does it take to reach a steady-state?
When the rate of administration = the rate of elimination
How would you use a drugs half life for prescribing?
What is the half-life of Digoxin?
half life of 24-36 hours. A change in dose would take a week to take effect.
What is the half life of amiodarone?
58 days – so it is usually started with a loading dose to acheive the clinical effect more quickly.
is used to measure the strength of an acid in solution.
is a measure of concentration of hydrogen ions in an aqueous solution.
The Henderson – Hasselbach equation solves:
If you know either pH or pKa you can solve for the other value using an approximation
Type of Type 1 hypersensitivity
Anaphalactic reaction (immune system gone wild)
example of Type 2 hypersensitivity
rH negative mother, giving birth to rH negative baby.
What happens with type 2 hypersensitivity
antibodies bind to the cell and neutralize the cell
what happens with type 3 hypersensitivity
Example of type 3 hypersensitivity
What happens with type 4 hypersensitivity
example of type 4 hypersensitivity
What three meds should not be combined with St. Johns wort?
SSRI antidepressants, Warfarin, Birth control
What happens when St. John’s Word is combined with SSRI antidepressants
It increases serotonin levels causing serotonin syndrome.
What happens when St. John’s Word is combined with birth control
It decreases the efficacy of the contraceptive; unplanned pregnancies
What happens when St. John’s Word is combined with Warfarin
st. john’s wort oral will decrease the level or effect of warfarin oral by altering drug metabolism.
St. John’s Wort also ____ the effectiveness of
HIV medications, cholesterol medications, and transplant medications
Activation of Alpha 2 receptors results in
How does Alpha 2 receptors lower BP?
ALpha 1 receptors are located mainly on…
Vascular smooth muscle (blood vessels, arteries, veins, urinary sphincters,)
breakdown of glycogen to glucose
Alpha 1 leads to inhibition of renin release which effects BP by
Renin is excreted by the kidneys and helps to lower BP
Alpha 2 recpetors are generally considered to work with the…..
Alpha 2 receptors affect the pancreas by
Beta 1 receptors are located mainly on the X and lead to X HR
Another place to find Beta 1 receptors is on the X, which releases X
Kidney, renin; which increases BP
Beta 2 receptors are mainly located on the X, but also located on;
Beta 3 receptors are mainly located in X tissue
adrenergic agonsists are made of 2 groups called…
catacholemine, non catacholemine
There are 3 types of adrenergic agonists
direct acting, indirect acting,mixed action
Direct acting agonsists bind to
alpha and beta receptors mimic NP and epinephrine. Non-selective –
Main route of direct acting agonists
increased cardiac output, increased BP
Norepinephrine stimulates which receptors
Alpha 1 – vasoconstriction (increased BP)
Indications for Norepinephrine
cardiac arrest and hypotensive shock
The three main meds of direct acting agonists (non-selective)
Norepinephrine, epinephrine, dopamine
What factors are associated with clinical judgment when prescribing medications?
Prescribing a drug is based on a thorough assessment of the patient and the patient’s environment. The determination of potential medical and nursing diagnoses, a review of the potential alternative therapies, specific knowledge about the drug chosen, and the disease process it is going to treat, known as patient centered care. The best therapy is usually the least invasive, least expensive, and the least likely to cause adverse reactions
What are the criteria for choosing an effective drug?
Multiple drugs may be able to treat a specific condition. You must consult nationally recognized guidelines for disease management to determine the most effective drug.
How does hypoalbuminemia affect the process of prescribing?
Many drugs that carry an electric charge are bound to albumin in the blood. The distribution of the drug to target tissues may be affected if hypoalbuminemia is present.
What is the drug’s half-life?
In clinical practice it takes about four to five times the half-life for a drugs concentration to read steady state after a drug is started, stopped or changed. Hal life is the amount of time for a drug to be half cleared.
What is meant by the onset of action, peak of action, duration of action of medications?
The onset of action is the time between the drug administration and the time that you see the drugs minimum effect. Onset is the first sign of a drugs therapeutic effect. Peak of action is the time of the maximum concentration of the drug in the blood. Duration of action is the onset of action and the metabolism of the drug below the dose needed for an effect.
Explain first pass metabolism.
This occurs when the concentration of the drug is greatly reduced before it reaches the systemic circulation. It is the portion of the drug lost during absorption. Generally, occurs in the liver or gut wall. After a drug is swallowed it is absorbed by the digestive system and enters the hepatic system. It is then carried by the portal vein to the liver before it reaches the rest of the body. The liver metabolizes many drugs to such an extent that only a small portion of the drug reaches the rest of the body. bioavailability of the drug thus is greatly reduced by the liver. Sublingual administration can bypass the first pass system plus it is also faster than oral route.
What is a steady state?
The overall intake of a drug is fairly and dynamic equilibrium with its elimination. Steady state is reached when the time of four to five times the half-life is reached since the drug had been started.
What factors affect the drug’s absorption?
Absorption involves several steps. First the drug must be introduced via route of administration and the form of medication like tablet or capsule. In IV or IM administration the absorption is less variable and bioavailability is near 100%. IV administration is considered to lose no portion of the drug. The fastest route of absorption is inhalation. Drugs must pass through the epithelial cells of the GI tract to be absorbed by the circulatory system. Cell membranes may affect the absorption of some drugs because they are made of lipid bilayers that are semi permeable. This means only small uncharged solutes can pass through the membrane. Whether or not a molecule is ionized affects the absorption, since ionic molecules are charged. Solubility favors charged species. Permeability favors neutral species. Some molecules have special channels to facilitate movement from the lumen into the circulation. The Henderson Hasselbeck equation offers a way to determine the portion that is ionized in a given pH. Weak acids will be present in their nonionic form in the stomach because of the acidic pH and bases will be in their ionic form. Nonionic species diffuse easier through cell membranes. Weak acids have a higher absorption rate in the stomach. The opposite is true in the basic environment of the stomach.
Identify drug metabolism and the role of the isoenzymes of the P450 system.
CYPs are the major enzymes in drug metabolism. Must drugs undergo deactivation by CYPs are directly facilitated secretion from the body. Many substances are bioactivated by CYPs to form their active compound. Many drugs increase or decrease the activity of CYPs isoenzymes either by inducing biosynthesis of an isozyme, which is enzyme induction or by directly inhibiting the activity of CYP which is enzyme inhibition. This is a major source of adverse drug reactions since changes in CYPs activity may affect the metabolism and clearance of certain drugs. When two drugs are both metabolized by the CYP450 system the drugs should be administered at separate times to prevent toxic effects.
What is the efficacy of the drug?
Efficacy is the maximum response achievable from a drug. Intrinsic activity is a term used to describe the efficacy of a drug relative to a drugs highest observed efficacy. Effectiveness refers to the ability of a drug to produce the wanted effect.
On the drug concentration curve what is the first sign of a therapeutic effect?
The onset of action.
What is the purpose of a peak and trough level?
To determine if the drug is within therapeutic range. Which is either dosage range or blood plasma or serum concentration usually expected to affect desired effects. Some patients require doses or concentrations above or below this range and some patients have toxicity within this range.
Describe the purpose of the blood brain barrier and the fetal placental barrier.
The blood brain barrier is a highly selective permeability barrier that separates circulating blood from the brain and ECF in nervous system. Formed by brain endothelial cells which are formed by tight junction with an extremely high electrical reductivity of at least 0.1 micron. The blood brain barrier allows passage of water, some gases and lipid soluble molecules by passage diffusion. As well as the selective transport of molecules like glycose and amino acids which are essential to neruo function. The placental barrier impedes certain chemicals however it allows fat soluble chemicals to cross. Drugs that are more water soluble and drugs with a higher molecular weight tend to not cross the placenta. If a drug binds to a large protein like albumin it is even less likely to cross the placenta.
What is the difference in distribution for each medication route?
Absorption has a many steps drug must be introduced via some route in order to be absorbed then distributed.
How will renal insufficiency affect drug elimination?
Kidney is primary excretion organ of drugs. General theme of metabolism is to produce a more water soluble and more easily removed by the kidneys. The rate at which a drug is excreted by the kidneys depends on several factors. Renal blood flow influences GFR glomerular filtration rate which is how much plasma is filtered per minute by the glomerulus. Renal excretion of drugs is usually well characterized it is the patients renal function that is variable. It is common to monitor renal function and adjust dosages based on renal function. Typically assessed by serum creatinine. Patients with poor renal function may have high levels of drugs secondary to decreased excretion metabolites.
Describe the effects of drugs based on the route of administration.
Absorption has a many steps drug must be introduced via some route in order to be absorbed then distributed.
Describe the role of the isoenzymes.
CYPs are the major enzymes in drug metabolism. Must drugs undergo deactivation by CYPs are directly facilitated secretion from the body. Many substances are bioactivated by CYPs to form their active compound. Many drugs increase or decrease the activity of CYPs isoenzymes either by inducing biosynthesis of an isozyme, which is enzyme induction or by directly inhibiting the activity of CYP which is enzyme inhibition. This is a major source of adverse drug reactions since changes in CYPs activity may affect the metabolism and clearance of certain drugs. When two drugs are both metabolized by the CYP450 system the drugs should be administered at separate times to prevent toxic effects.
According to the WHO, what is the first step in the prescribing process?
The first step is defined the patient’s problem to generate a clear indication for treatment. A summary of the diagnostic part of the consultation signs symptoms diagnosis and relevant patient characteristics like comorbidities, comedication pregnancy and drug allergies. This step is the basis for choosing and prescribing the correct treatment during the next steps. Second step is specific objectives with measurable parameters. Third step is to choose drug needed first part of this step is the p drug (preferred drug selection and part two is confirmation of drug. Step four is begin treating with p drug patient education is step five step six involves evaluating p drug (continue adjust or stop).
What does the FDA have the authority to approve?
FDA is responsible for protecting and promoting public health through the regulation and supervision of food safety, tobacco products, prescription and over the counter drugs, biopharmaceutical, vaccines, blood transfusions medical devices cosmetics animal foods and feed and vet products. Post marketing surveillance is how the FDA monitors drug safety. It also determines all of the labeling for all prescription and over the counter meds. FDA does not regulate herbal supplements.
What is off label prescribing?
Off label use is the prescription of drugs for un approved indication or age group dosage of route of administration. Both prescription and otc drugs can be used in off label ways. However, most studies focus on prescription drugs. Off label use is legal unless it violates ethical or safety guidelines. There can be health risks or differences in legal liability.
What factors place an infant and child at risk when prescribing medications?
In general, there is a lack of safety studies related to medications and the pediatric population. Adverse drug reactions are most common in this age group. Children are not just small adults they metabolize drugs differently than adults.
What adverse drug reactions (ADRs) are the elderly at risk of developing?
Physiological changes in elderly adults affect mainly how medications are metabolized by the kidney and liver. Hepatic blood flow nearly decreases by 1/2 or 40 % in older adults, and some degree of chronic kidney disease is present in nearly ½ of older adults. The median renal blood flow decreases by ½ by the time the patient is 80 years old. Although individual rates vary and 1/3 of older adults maintain normal renal function. Heart failure affects more than 40% of persons older than 80 years. This further reduces the function of aging kidneys and liver. Aging decreases first pass clearance in the liver and a number of common drugs like warfarin, benzodiazepines, and opiates require much lower diseases in older adults. Distribution of drugs to body compartments is changed by the decrease in the ratio of lean body weight to body fat. Levels of serum proteins which bind to many drugs decrease in older adults because of malnutrition and dietary changes that are common for both intentional and unintentional reasons. Drug metabolism can be affected by drug abuse like alcohol. Up to 10 % of older adults are heavy or problem drinkers.
What are the ADRS related to special populations?
These can be related to genetics, age, gender, drug interactions, and medical conditions.
Type 1 hypersensitivity
immediate is a reaction provoked by reexposure to a specific type of antigen or allergen. Symptoms include mild irritation to anaphylactic shock.
Cytotoxic hypersensitivity the antibodies produce an immune response that binds to antigens (allergens) at the surface of the cell. Antigens can be either intrinsic (apart of the body)or extrinsic (outside of the body). ABO blood incompatibility where the blood cells have a different antigen on them. B cell proliferation will take place, and antibodies to foreign blood types are produced. IgG and IgM bind to these antigens to form complexes that activate the pathway of the complement activation to eliminate cells presenting as foreign antigens. That is mediators of acute inflammation are generated at the site and membranes attack cause cell lysis and death. This reaction takes hours to a day.
Type 2 hypersensitivity
accumulation of immune complexes or antigen-antibody complexes that may not have been adequately cleared by innate immune cells giving rise to an inflammatory response and attraction of leukocytes. Such reactions that progress to disease produces immune complex diseases. The reaction can take hours, days, or weeks depending on whether or not there is an immunologic memory of the precipitating antigen. Typically clinical features begin a week following the initial antigen challenge causing the immune complexes to cause an inflammatory response.
Type 3 hypersensitivity
delayed this reaction takes 2-3 days to begin. Unlike other types of reaction, it is not antibody meditated but a cell-mediated response.
Type 4 hypersensitivity
Which medications interact with St. John’s Wort?
A medicinal herb with antidepressant effects and potent anti-inflammatory properties. St Johns wort interacts with SSRIs, warfarin, and birth control. Taking with SSRIs can lead to an increased serotonin level causing serotonin syndrome. Combining estrogen contraceptives with st johns wort can lead to decreased efficacy of the contraceptive. Decreases the efficacy of HIV meds, cholesterol meds, and transplant meds.
How does doxazosin work?
It is an alpha one adrenergic blocker that inhibits the binding of norepinephrine released from the sympathetic nerve terminals to the alpha one receptors and then to the membrane of vascular smooth muscle cells. The primary effect of this inhibition is relaxed vascular smooth muscle tone or vasodilation which increases peripheral vascular resistance leading to decreasing blood pressure. It is used to treat high blood pressure and urinary retention associated with benign prostatic hyperplasia (BPH). Also shows potential to treat erectile dysfunction and chronic epididymitis. Adverse effects include orthostatic hypertension and reflex tachycardia.
What is the action and effect of beta blockers?
Beta blockers are a drug class used to manage cardiac arrhythmias. Used to prevent a second attack after the first heart attack this is called secondary prevention. They have been used in hypertension but are no longer the first choice of treatment. Beta blockers block the action of endogenous catecholamines (epi & nor-epi) on adrenergic beta receptors of the sympathetic nervous system which mediates the fight or flight response Some block all activation of beta-adrenergic receptors and some are selective. The three types of beta receptors are known as beta 1, beta, 2, and beta three receptors. Beta 1 adrenergic receptors are mainly located in the heart and kidneys. Beta 2 receptors are mainly in the lungs, gi tract, liver, uterus, vascular smooth muscle and skeletal muscle. Beta 3 receptors are located in fat cells. Beta receptors are found in cells on the heart muscle, smooth muscle, airways arteries, kidneys and other tissues that are apart of the sympathetic nervous system and lead to stress responses especially when stimulated by epi. Beta-blockers interfere with the binding of epi and other stress hormones and weaken the effects of stress hormones. There are two types of beta blockers non-selective agents which can bind to both beta 1 & beta two receptors, include propranolol and carteolol but carteolol also has alpha blocking activities which can cause vasodilation of the peripheral vascular system, and labetalol as well. Beta 1 selective agents or cardioselective have inotropic effects as well as reducing smooth muscle tone these include atenolol esmolol and metoprolol.
What are the adverse effects of beta blockers?
Adverse effects of beta two adrenergic antagonists activity include bronchospasm, peripheral vasoconstriction, alteration of glucose and lipid metabolism. Less common with beta one selective (cardioselective) but report selectively diminishes at higher dosages. Beta blockade especially beta one receptor macula densa inhibits renin release thus decreasing the release of aldosterone causing hyperkalemia and hyponatremia. Beta 1 can increase plasma lipid and glucose levels in people with diabetes can also interfere with oral diabetic meds in general beta blockers should be avoided in people with diabetes. Beta blockers also should be avoided for patients with asthma, cocaine use or cocaine-associated tachycardia. Adverse drug reactions include nausea, diarrhea, bronchospasm, dyspnea, cold extremities, exacerbation of raynauds, bradycardia, hypotension, heart failure, heart block, fatigue, alopecia, dizziness, abnormal vision, hallucinations, insomnia, nightmares, ED, sexual dysfunction, and alteration of glucose metabolism.
What effect will result with rapid withdrawal of a beta blocker?
A coronary artery spasm that can result in an MI. This most often happens in a patient with a history of coronary artery disease.
What patient teaching should be provided when prescribing clonidine or any centrally acting alpha-agonist?
Clonidine treats high blood pressure by stimulating alpha two receptors in the brain which decrease peripheral vascular resistance thus lowering blood pressure. The risk of rebound hypertension is increased in alpha agonists o it is important to not miss any doses.
What are the adverse effects of a beta one selective blocker?
Serious side effects that are advised to report immediately include bradycardia, dizziness fainting, and fatigue, cyanosis of fingers and toes, numbness, tingling, and/or swelling in hands or feet, sexual dysfunction, hair loss, mental or mood changes, depression, trouble breathing, cough, dyslipidemia, and increased thirst.
What effect is produced with cholinergic blockers?
An anticholinergic agent is a substance that blocks the neurotransmitter acetylcholine in central and peripheral nervous system. Anticholinergics inhibit parasympathetic nerve impulses by selectively blocking the binding of neurotransmitter acetylcholine to its receptor and nerve cells. The nerve fibers in the parasympathetic nervous system are responsible for the involuntary movement of smooth muscles. Smooth muscles are present in GI tract Gu tract and lungs. Anticholinergics are divided into three categories which are antimuscarinic agents, ganglionic blockers and neuromuscular blockers. Anticholinergic drugs are used to treat many conditions which include GI disorder, GU disorders, respiratory disorders, sinus bradycardia, insomnia, dizziness. Anticholinergics typically have an antisialagogue effect or decrease salvia production and can produce a level of sedation for many of these effects cholinergic analogs produce the opposite effects.
Aderenergic agonists are made up of two group what are these two groups?
Catacholimine and non catacholmine
What are antichollenergic drugs used for?
Antichollenergics are used in GI disorders like gastritis, diarrhea, pylorospasm, diverticulitis, ulcerative colitis, nausea and vomiting; genitourinary disorders cystitis, urethritis, prostatitis; respiratory disorders like asthma, chronic bronchitis, COPD, sinus bradycardia due to hypersensitive vagus nerve, insomnia although usually only for a short term basis, dizziness including vertigo, motion sickness related symptoms.
What are the three main medications that are non-selective/direct acting agonists?
Norepinephrine, epinephrine, and dopamine
What receptors does norepinephrine stimulate?
Alpha 1 causing vasoconstriction, thus increasing blood pressure
Beta-adrenergic blockers, the most widely used adrenergic blockers, work by?
preventing stimulation of the sympathetic nervous system by inhibiting the action of catecholamines at beta-adrenergic receptors.
Beta 1 receptors occur where?
heart, kidney,
Alpha 1 receptors are located where?
Mainly on smooth muscle throughout the body, on iris, urinary system, liver, kidney
When alpha 1 is activated what occurs?
Vasoconstriction- heart, mydrasis- iris, urinary retention- urinary, glycogenolysis- liver, & release of renin- kidney
Alpha 2 receptors are located where?
GI- slow digestion & pancreas-decrease insulin secretion
Beta 1 receptors cause?
Increase contractility, increase heart rate, & increase av node conduction-heart, kidney- increase renin release/increase BP
Beta 2 receptors occur where?
lungs, vascular smooth muscle & arteries of skeletal muscle, GI & Uterus, & Pancreas
Beta 2 receptors cause?
bronchodialation- lungs, vasodilation-vascular smooth muscle & arteries of skeletal muscle, decrease motility-GI, increase in insulin- pancreas, & inhibition of labor- uterus
Beta 3 receptors occur where?
fat tissue, urinary
Beta 3 receptors cause?
breakdown of stored fat-fat, urinary- relaxation of bladder
Cholinergic receptors include? Muscurinic and nicotinic
Muscurinic receptors are found where?
M1- GI, M2- Cardiac, M3- Seceratoty glands, lungs, & smooth muscles in eyes
Muscurinin receptors cause?
m1 & m3- increased calcium M2- increase potassium & decrease HR
Nicotinic receptors are found where?
Neuromuscular junction- NM NN-CNS
Nicotinic receptors cause?
NM- Muscle contraction & NN- transmission of cholinergic signals
Cholinergic drugs?
acetylcholine- decrease cardiac output, decrease hr, decrease bp, & increase GI (direct acting), Physostigmine-reverses atropine (indirect reversible), & donepezil- reduce effects of Alzheimers (indirect reversible)
Cholinergic drug adverse effects?
diarrhea, urination, miosis/muscle weakness, bronchorrhea, bradycardia, emesis, lacrimation, salavation/sweating
Anticholinergic categories?
Antimuscarinic, ganglionic blockers, & neuromuscular blockers
Antimuscarinic drugs?
Atropine (eye- hydrasis), (GI tract-prolonged gastric emptying), (heart-tachycardia),& (salivary/sweat glands- dry mouth & skin), scopolamine- motion sickness & post op n&v, oxybutinin- urinary urgency
Anticholinergic adverse effects?
agitation, blurred vision, confusion/constipation, dry mouth, & stasis of urine & sweat
Ganglionic blocker drugs?
nicotinic receptor affected/blocked by Nicotine
Neuromuscular blockers?
nondeploarizing agents – rocuronium & vecuronium depolarizing agents- succinylcholine