Pharmaceutic phase

DISSOLUTION

is the fist phase of drug action

In the pharmaceutic phase the drug becomes a solution so that it can:

Cross the biological membrane

Which form of drug is the most rapidly absorbed from the GI Tract?

Liquid Suspension

Drugs need to be in a solution so that they are absorbed

pharmacokinetics

is the process of drug movement to achieve drug action.

Absorption--> distribution --> metabolism-->and excretion

Protein- based drugs are destroyed by the

small intestine by digestive enzymes

such as insulin and growth hormones

According to your text a drug that is NOT highly protein bound would be:

Freely distributed to the extravascular tissue

The route for drug absorption that has the greatest bioavailability is:

Intravenous

Passive absorption

occurs mostly by diffusion (movement from higher concentration to lower). With the process of diffusion, the drug does not require energy to move across the membrane.

Active absorption

requires a carrier such as an enzyme or protein to move the drug against a concentration gradient. Energy is required.

Pinocytosis

is a process by which cells carry a drug across their membrane by engulfing the dug particles.

drugs that are lipid soluble pass

pass rapidly through GI membranes. The GI membrane is composed mostly of lipid and protein, so drugs pass easily.

Water-soluble drugs need a

Carrier.

either enzyme or protein to pass through the membrane

Large particle pass through a cell membrane if the are

Non ionized (have no positive or negative charge).

*weak acid drugs such as aspirin are less ionized in the stomach, and they pass through the stomach lining easily and rapidly.

Drugs that are lipid soluble and nonionized are absorbed ____ than water-soluble and ionized drugs

FASTER

The process in which the drug passes to the liver first is called

FIRST- PASS EFFECT, or hepatic first pass

Bioavailability

is the subcategory of absorption. It is the percentage of administered drug dose that reaches the systemic circulation.

The serum half-life of a drug is the time required:

After absorption for half of the drug to be eliminated

T.C. has liver and Kidney disease. He is given a medication with a serum half-life of 30 hours. You expect the DURATION OF ACTION of this medication to:

Increase

Free drugs

(drugs not bound to protein) are active and can cause a pharmacologic response. The portion of the drug that is bound is inactive because it is not available to receptors.

As free drug in the circulation decreases, more bound drug is released from the protein to maintain the balance of free drug.

When two highly protien bound drugs are given concurently

they compete for protein-binding sites, thus causing more free drug to be released into the circulation.

Primarily ___ is what protein binding drugs bind to

albumin

For elimination through the Kidneys to be possible, a drug must:

Be Water-Soluble

Creatinine is normally excreted in urine as metabolic waste. However in a renal disorder you would expect the blood creatinine level to be:

Increase

Metabolism

body inactivates or bio transforms drugs. Primary site is the liver. Most drugs are inactivated by liver enzymes and are then converted or transformed by hepatic enzymes to inactive metabolites or water-soluble substances for excretion.

A large % of drugs are lipid soluble; thus the liver metabolizes the lipid-soluble drugs substances to______

water-soluble substance for renal excretion

factors affecting ABSORPTION

• route
• preparation
• dosage
• digestive motility
• digestive enzymes
• blood flow at administration
• lipid solubility
• degree of ionization
• pH of local environment
• drug-drug, drug-food interactions

Cytochrome P450 is a

family of isozymes responsible for the biotransformation of several drugs.

• enzyme induction
• enzyme inhibition

Drug metabolism via the cytochrome P450 system has emerged as an important determinant in the occurrence of several drug interactions that can result in drug toxicities, reduced pharmacological effect, and adverse drug reactions. Recognizing whether the drugs involved act as enzyme substrates, inducers, or inhibitors can prevent clinically significant interactions from occurring.

Prodrugs

converted from inactive form to active

Most drugs are excreted by the kidneys..other routes include?

Kidney = #1

bile, feces, lungs, saliva, sweat, and breast milk

Acidic urine promotes the elimination of _____ & alkaline urine promotes elimination of ______

weak based drugs

weak acid based drugs

Pharmacodynamics

is the study of the way drugs affect the body.

Drug response can cause a primary or secondary physiologic effect or both. The primary is desirable, the secondary effect may be desirable or undesirable.

Dose response =

the relationship between the minimal vs the maximal amount of drug needed to produce the desired affect.

Onset of action

is the time it takes to reach the minimum effective concentration after a drug is administered.

Peak action=

occurs when the drug reaches its highest blood or plasma concentration

Duration of action=

the length of time the drug has a pharmacologic effect

drugs act through receptors by ?

binding to the receptor to produce (INITIATE) a response or to block (PREVENT) a response

The better a drug fits at the receptor site, the more biologically active the drug is.

agonist drugs

drugs that produce a response

antagonist drugs

drugs that block a response

Cholinergic receptors pg.8

are located in the bladder, heart, blood vessels, stomach, bronchi, and eyes.

A drug that stimulates or blocks the cholinergic receptors affects the anatomic sites of location.

Categories of Drug Action

1. stimulation or depression

2. replacement

3. inhibition or killing of organisms

4. irritation

The biological activity of a drug is determined by the:

Fit of the drug at the receptor site

A mechanism of drug action that does not involve a receptor or enzyme such as a cancer drug is:

Nonspecifc

Drugs that attach but do not elicit a response are called:

Antagonists

Knowledge of drug potency does NOT enable us to predict whether a potent drug is more or less toxic. The valid indicator that measures the margin safety of the drug is its:

Therapeutic Index

Drugs with narrow therapeutic ranges such as digoxin (0.5-2 ug/ml), require plasma/serum drug level monitoring _____ to avoid drug toxicity.

At periodic Intervals

After drug administration, the highest plasma/serum concentration of the drug at a specific time is called:

Peak Level

Prior to administration of a medication, the nurse should check a drug reference book to obtain the following pertinent data for:

1. Protein-binding effect

2. Half-Life

3. Therapeutic Range

A time response curve evaluates three parameters of drug action, which does NOT include:

Therapeutic Range

When immediate drug response is desired, a large initial dose is given to rapidly achieve an MEC in the plasma.

Loading Dose

Peak drug levels

indicate the rate of absorption of the drug

highest concentration of a drug

trough drug levels

indicate the rate of elimination of the drug

lowest concentration of a drug

drugs with a high therapeutic index have a

wide margin of safety and less danger of producing toxic effects

Side effects and adverse reaction

are physiologic effects not related to desired drug affects.

Adverse reaction are more severe than side effects.

Tolerance

refers to a decreased responsiveness over the course of therapy.

Absorption, Distribution, Metabolism(biotransformation), Excretion of drugs by the body

Pharmacokinetics

Biochemical and Physical effects of drugs and mechanism of drug actions

Pharmacodynamics

Name given by United States Adopted Name Council

Generic (NONPropietary) Name

Celeste =

Hoe

Lety=

(no comment)

Pregnancy Category A

No risk to fetus

Pregnancy Category B

no risk to animal fetus but information in humans is unavailable

Pregnancy Category C

Adverse effects in animal fetus, in humans is unavailable

Pregnancy Category D

Possible fetal risk in humans reported, however potential benefit may in selected cases may warrant use of drug

Pregnancy Category X

Fetal Abnormalities reported and positive evidence of fetal risk in humans is available from animal/human studies. Never should be taken by pregnant women.

Therapeutic action of drug

Risk Vs. Benefit

Benefits

Side Effects/ Adverse reactions or contraindication

Risk Vs. Benefit

Risk

prevention of disease through vaccine

Prophylactic (Drug Therapy)

Drug bound to protein, cause inactive drug action/response

Protein bound drug

Not bound to protein causing pharmacologic response that is active.

Free Drug

As it decreases, more bound drug is released from protein

Free drug

Time it takes for one half concentration to be eliminated

Half-Life

Drug reaches highest blood/plasma concentration

Peak Action

length of time drug has pharmacologic effect

Duration of Action

Medication given on time.

Given at Correct time.

Lab aware of tests.

Set up blood draw

Responsibilities of Nurse obtaining Peak And Trough

Indicate Time of highest plasma concentration & Rate of absorption.

Peak

Time of lowest plasma concentration & Rate of Elimination

Trough

IV, IO

ET, INHALATION

SL, RECTAL, BUCCAL

IM

SQ

PO

ROUTES of Drug Admin. in ORDER OF RAPID ABSORPTION

"RIGHT" Medication Administration check list

right drug

right dose

right time

right route

right patient

What Nurse listens to from pt as they list symptoms

Subjective Data

What Nurse Observes

Objective Data

Dissolution of the drug

Pharmaceutic

Effect of drug action because of hereditary influence

Pharmacogenetic

4 processes of drug movement to achieve drug action

Pharmacokinetic

Effect of drug action on cells

Pharmacodynamic

Drug that block a response

Antagonist

Drug that produces a response

Agonist

Drug absorbed by diffusion

Passive Absorption

Which type of drug passes rapidly through the GI Membrane?

Lipid-Soluble and nonionized

What Affects a drug absorption?

Hypotension, Pain, Stress

Two drugs given together cancels the effect of each other

Antagonistic Effect

Adrenergic agonist affect the..

sympathetic nervous system

Sympathomimetics affect the ...

sympathetic nervous system

Adrenergic receptors are typically found where in the body?

effector cells of muscles, such as the heart, bronchiole walls, gastrointestinal tract, urinary bladder, and ciliary muscle or the eye.

What does and Alpha ONE receptor do?

increases force of heart contraction; vasoconstriction increases blood pressure; mydriasis (dilation of pupils) occurs; decreases secretion in salivary glands; increases urinary bladder relaxation and urinary sphincter contraction.

What does an Alpha TWO receptor do?

Inhibits release of norepi; dilates blood vessels; produces hypo-tension; decreases gastrointestinal motility and tone.

Beta ONE receptors do?

Increases heart rate and force of contraction; increases renin secretion, which increases blood pressure.

Beta TWO receptors do?

dilates bronchiloes; promotes gastrointestinal and uterine relaxation; promotes increase in blood sugar through glycogenolysis in liver; increases blood flow in skeletal muscles

alpha-adrenergic receptors are located in

blood vessels, eyes, bladder, and prostate

alpha 2 receptors are located in the

the postganglionic sympathetic nerve endings.

Beata 1 receptors are located in the

kidney but primarily the heart

beta 2 receptors are found mostly in the

smooth muscles of the lung and gastrointestinal tract, the liver, and the uterine muscle.

Schedule I

heroin, hallucinogens (LSD, marijuana[except when prescirbed with cancer treatment], mescalin, peyote, psilocybin.)

*high potential for drug abuse not accepted medical use.

Schedule II

*high potential for drug abuse. Accepted medical use. Can lead to strong physical and psychological dependency

ex: demerol, morphine, hydrocodone, methadone, oxycodone

What schedule is cocaine?

schedule II

schedule III

*Medically accepted drugs.Potential abuse is less that that of schedule I and II. May cause dependence.

Schedule IV

*Medically accepted drugs. May cause dependence.

Schedule V

*Medically accepted drugs. Very limited potential for dependence.

(codeine in cough preparations)

What is the nurses role in administering controlled substances?

• account for all controlled drugs
• keep a special controlled-substance record for required information.
• countersign all discarded or wasted medication;wastage must be witnessed.
• ensure that documentation and drugs on hand match.
• keep all controlled drugs in a locked storage area

misfeasance

negligence; giving the wrong drug or drug dose that results in the patient's death.

nonfeasance

omission; omitting a drug dose that results in the patient's death

Malfeasance

giving the correct drug but the wrong route that results in the patient's death

How do you know a generic drug is just as effective?

*it is given an "A" rating

generic drugs have the same active ingredients as brand name drugs but are usually less expensive because manufacturers do not have to do extensive testing; these drugs were clinically tested for safety and efficacy by the pharmaceutic company that first formlated the drug.

Pharmacogenomics

refers to the general study of all the different genes that determine drug behavior.

an enzyme system either induces or inhibits the action of substrates. Induction or inhibition of a substrate accounts for the variations in drug metabolism in individuals and groups.

Cytochrome P-450 enzyme system

Poor metabolizers of antidepressants, antipsychotics, cardiovascular agents, and isoniazid, which can lead to toxicity

people of european descent

Many have diminished therapeutic, effects from beta blockers, ACE inhibitors, and warfarin sodium

People of African descent

drug interaction

as an altered or modified action or effect of a drug as a result of interaction with one or multiple drugs.

Pharmacokinetic interactions

are changes that occur in the absorption, distribution, metabolism or bio-transformation, and excretion of one or more drugs

One drug can block, decrease, or inccrease the absorption of another drug. It can do this by?

1. by decreaseing or increasing gasric emptying time
2. by changing the gastric pH
3. by forming drug complexes

Category I - over the counter drugs

drugs judged to be safe and effective

Category II- OTC

drugs judged to be unsafe or ineffective; these drugs should not be included in nonprescription products

Category III- OTC

drugs for which there is insufficient data to judge safety or efficacy

drug misuse

indiscriminate or recration use of a chemical substance or its use for purposes other than those for which is intended.

drug abuse

drug use inconsistent with medical or social norms

How do you define addiction

a compulsive, uncontrollable craving for and dependence on a substance to such a degree that cessation causes severe reactions

what is tolerance

the need for a larger dose of a drug to obtain the original euphoria.

Decreased effect of a substance that results from repeated exposure. It is possible to develop cross-tolerance to other substances in the same category

what is craving for a drug

subjective need for a substance, usually experienced after decreased use or abstinence. Cue-induced craving is stimulated in the presence of situations previously associated with drug taking.

Withdrawal syndrome

Constellation of physiologic and psychologic responses that occur when there is abrupt cessation or reduced intake of a substance on which an individual is dependent or when the effect is counteracted by a specific antagonist

Metabolism of Alcohol?

• Absorption into the blood stream--> primarily in small intestine-->some in stomach.
• Metabolized by the liver
• Excreted-->Urine --> breath 5%-->sweat (smell drunk)

Alcohol Pharmacology

• CNS depressant
• Affects various neurotransmitter systems

1. gaba, glutamate, dopamine, opioid
2. enhances the inhibitor effects of GABA on its receptor

Alcohol toxicity ..what happens?

• cant communicate
• irregular/slow heart rate
• hypothermia
• respiratory depression
• coma
• death

*dangerous in combo with other depressants

Physiological effects of Cocaine

• lasts 1-2 hours
• increased energy and motor activity
• increased heat rate and BP
• euphoria
• decreased appetite
• mental alertness
• increased body temp
• dilated pupils

Cocaine toxicity looks like?

• rapid heart beat
• hallucinations
• paranoid delusions
• tremors and convulsions
• respiratory failure
• heart attack or heart failure
• stroke

Physiological effects of Meth

• similar to cocaine
• irritability and aggression
• anxiety and or paranoia/nervousness
• increased wakefulness
• tremors/convulsions
• decreased appetite
• insomnia
• high BP and heart rate

Meth toxicity ?

• neurotoxic : serotonergic neurons and dopaminergic neurons
• Permanent psychosis
• hyperthermia
• kidney failure
• coma
• stroke
• heart attack

Aloe Vera

externally used for treatment of minor burns, insect bites, and sunburns. (fresh is better)

Some success with the treatment of dandruff, oily skin, and psoriasis.

Taken internally, aloe vera is a powerful laxative.

Menstrual flow is increased with small doses.

Garlic: what is it good for?

detoxifies body and increases immune function; decreases platelet aggregation; increases HDL and decreases cholesterol and triglycerides.

Caution: with prescription anticoagulants because of increased fibrinolysis and decreased platelet aggregation

SE: heartburn, flatulence, gastric irritation, decreased RBC, dizziness, diaphoresis

Ginkgo biloba

Antioxidant; peripheral vasodilation and increased blood flow to CNS, reduces platelet aggregation.

Uses: allergic rhinitis, Alzheimer's, anxiety/stress, dementia, vertigo, poor circulation, altitude sickness. Erectile dysfunction.

Role of the nurse when it comes to educating about herbal therapies

• obtain history
• risks vs benefits
• purchase
• storage
• potential interactions
• Do not give to: pregnant or nursing..infants or young children

Pharmacodynamics in the pediatric pt

• differences in body composition
• variability in body water,fat, protein amounts

Pharmacokinetics in the pediatric pt

• immaturity of organs and systems
• greatest effect in newborns and infants

Absorption and the pediatric pt

• reduced gastric acidity
• irregular gastric emptying
• thinner skin- topicals easily absorbed

Distribution in the pediatric pt

• more body water= less drug concentration

Metabolism in the pediatric pt

higher metabolic rates

Excretion in the pediatric pt

immature kidneys

Pharmacokinetics in the geriatric pt (absorption, distribution, metabolism, excretion)

• Absorption: decreased acidity, motility, and blood flow.
• Distribution: decreased protein binding sites and body water. Increased body fat
• Metabolism: decreased liver function
• Excretion: decreased kidney function

Pharmacodynamics in the geriatric pt

• decreased receptors
• decreased affinity
• Altered response to drugs R/T CNS changes
• decreased compensatory response
• higher risk for ADR (?)
• May need lower dose
• may need higher dosing intervals

The geriatric pt and Cardiac glycosides

careful monitoring

the geriatric pt and Anticoagulants

warfarin highly protein bound---> albumin levels are low= high free drug

*close monitoring

The geriatric pt and GI drugs

• Anit-ulcer agents--AVOID TAGAMET
• laxatives

TAGAMET= CAUTION: not good for the older adult..it interacts with every other drug

Are home health aide allowed to give medication?

legally home health aids may only assist with medications the patient customarily self-administers.

What happened to the babies that were born after mom took THALIDOMIDE for morning sickness?

Herbal use and pregnancy

Moms need to be managed on how they can affect the body

Iron and pregnancy

need more RBC= higher blood volume

-dark leafy greens, fortified meats.

-begin in the 2nd trimester

-take on empty stomach

-main issues include constipation, dark stools, nausea.

-Relief: fiber and water

Folic acid and pregnancy (vitamin B9 & folate)

• help prevent against neural tube defects
• should start taking a few months before conseption
• 400-800mcg
• can be found is fortified cereal, broccoli, bread...

What is Tocolytic therapy?

• drug therapy to decrease uterine muscle contraction
• #1 use is calcium antagonist magnesium sulfate
• calcium channel blockers prevent influx of calcium ions, resulting in relaxation of the myometrium

Moral of the story: if you limit the available calcium= interrupt uterine contractions= additional time for fetal maturation & delay delivery