Chapter 2

Describe absorption.

the process whereby a drug is transferred from its site of entry into the body to the circulating fluids of the body how the medicine gets into the body system dependes on route of administration

Describe metabolism.

the process whereby the body inactivates drugs how the body gets rid of the medication depends on enzyme systems

Describe the trough level.

drawn right before the next dosage

Descrive liberation.

drug is released from the dosage form and dissolved in body fluids

If the drug level does not reach the minimum effective concentration (MEC) then...

there will be no pharmacologic effect

Once a medication is protein bound, ---- - expect higher dosages because it takes a lot to get the right amount in circulation

it cannot do anything

What is being described below? •Drug released from dosage form and is dissolved in body fluid •Process of converting oral drug can be influenced by food and water in the stomach

liberation

What is the main organ that is used for metabolism?

liver

What is being described below? •The process whereby the body inactivates drugs •Primary organ of metabolism is the liver; other sites are GI tract and lungs

metabolism

Describe the antagonistic effect.

one drug interferes with the action of another

What are unbound drugs>

pharmacologically active portion the ones that are doing the job

If a drug is 90% bound to a protein, then 10% of the drug is...

providing the physiologic effect

Describe distribution.

refers to the ways in which a drug is transported throughout the body by the circulating body fluids to the sites of action or to the receptors that the drug affects how the medicine is distributed through the body; through the blood system to the target location depends on circulation to be transported throughout the body

The ---- does most of the work for absorption.

small intestines

What are drug receptors?

specific sites where drugs form chemical bonds

What is pharmacodynamic?

study of interactions between drugs and their receptors and the series of events that result in a pharmacologic response

Drugs act by forming chemical bond with specific receptor sites, similar to a key and lock. The better the fit...

the better the response

Describe the synergistic effect.

the combined effect of two drugs is greater than the sum of the effect of each drug given together

Describe displacement.

the displacement of the first drug from protein-binding sites by a second drug increases the activity of the first drug because more unbound drug is available interrupts protein binding

Describe excretion.

the elimination of drug metabolites and, in some cases, of the active drug itself from the body we pee and poop out drugs

Describe interference.

the first drug inhibits the metabolism or excretion of the second drug, thereby causing increased activity of the second drug

Describe incompatibility.

the first drug is chemically incompatible with the second drug, thereby causing deterioration when the drugs are mixed in the same syringe or solution or are administered together at the same site signs include haziness, formation of a precipitate, or a change in the color of the solution when the drugs are mixed

If the peak level exceeds the toxicity threshold...

toxic effects will result

Describe the additive effect.

two drugs with similar actions are taken for an increased effect

In terms of absorptive surface, what does bariatric surgery cause?

If your patient has had bariatric surgery there is not a lot of surface area in their small intestines

Describe an elixir.

Liquid medicines; sometimes the medication will settle in the bottom and you want to shake it

Describe a tablet.

Some tablets can be broken in two but not all; they will have a score or a line if it can be separated

---- is the most important body fluid to get medications to where they need to go.

blood

What is being described below? •Drugs are transported throughout the body by body fluids to the sites of action •Protein binding and fat solubility affect distribution •Organs with largest blood supply receive the distributed drug most rapidly •The heart, brain, kidney, liver are the organs that are most vascular and need to most blood •Some drugs cannot pass through the blood-brain barrier or the placental barrier

distribution

Describe the peak level.

drawn when you believe the dose is at its highest concentration

A time-response curve, which is also known as a ----, demonstrates the relationship between the administration of a drug and the patient's response.

drug concentration-time profile

What is an antagonist?

drugs that attach to a receptor but do not stimulate a response puts a barrier up; kind of like caution tape on a crime scene

What is an agonists?

drugs that interact with a receptor to stimulate a response bind to the receptor site; fits like a lock and key - there job is done and they are happy

What is being described below? •Elimination of drug metabolites and some of the active drug from the body •Kidneys are the major organ of excretion; some excreted in feces •A patient with poor kidney function will have an increased action and duration of a drug

excretion

What two things increase absorption?

heat and massage

What are the two ways drug interactions are elicited?

1. By agents that, when combined, increase the action of one or both drugs 2. By agents that, when combined, decrease the effectiveness of one or both drugs

What are 6 drug interactions?

1. additive effect 2. synergistic effect 3. antagonistic effect 4. displacement 5. interference 6. incompatibility

Describe the parenteral route of drug administration.

Bypasses the GI tract by using subcutaneous, intramuscular, and intravenous injection Parenteral works faster than enteral drugs

What are 5 adverse effects of drugs?

1. desired action 2. side effects 3. adverse effects (common and serious) 4. idiosyncratic reactions 5. allergic reactions

What are the 3 routes of drug administration?

1. enteral 2. parenteral 3. percutaneous

What are some factors affecting absorption?

1. route of administration 2. food and fluids 3. dosage formulation 4. status of absorptive surface (GI mucosa, skin) 5. rate of blood flow to small intestine 6. stomach acidity (higher acidity breaks down faster) 7. status of GI motility (how fast does the drug move through the body)

List the 7 medication forms.

1. tablet 2. capsule 3. elixir 4. enteric-coated 5. suppository 6. suspension 7. transdermal patch

All drugs are processed in the body through pharmacokinetics. What is the correct order that drugs pass through the body? a)Liberation, absorption, distribution, metabolism, excretion b)Distribution, metabolism, liberation, absorption, excretion c)Biotransformation, liberation, distribution, absorption, excretion d)Excretion, distribution, liberation, absorption, metabolism

A

Describe the percutaneous route of drug administration.

Absorbed through the skin and mucous membranes Inhalation, sublingual, or topical

---- is very important because most drugs bind to proteins.

Albumin

A patient reports postoperative pain, and the nurse administers morphine (a narcotic analgesic) intravenously to ease the pain. Fifteen minutes later, the nurse notes that the patient is very drowsy, respirations are slow and shallow, and oxygen saturation is low. The nurse administers another drug that decreases the action of the morphine. What is this effect called? a)Displacement b)Antagonistic c)Interference Synergisti

B The morphine had a greater-than-desired effect on the patient. Because the drug was given intravenously, it is impossible to remove the drug from the patient's bloodstream. Therefore, the nurse does the next best thing and administers another drug that interferes with the action of the first, otherwise known as an antagonistic effect. The result is a decrease in the action of the original drug. The second drug is sometimes referred to as the antidoteto the first.

A patient is being started on a new drug that has been used safely by many people for years. The patient has no known allergies, and the nurse administers the drug correctly. Suddenly the patient experiences cardiac arrest. What is this type of reaction called? a)Allergic b)Mutagenic c)Idiosyncratic d)Therapeutic

C Because the drug was a known safe drug and the patient had no known reason not to receive it, the response to the drug in this case was totally unexpected, or idiosyncratic. An allergic response is typically preceded by such reactions as rash, hives, tingling, or swelling.

Describe drug blood level.

When a drug is circulating in the blood, a blood sample may be drawn and assayed to determine amount of drug present -You should have an equal amount of free medication to protein-bound medications Important for certain drugs, like anticonvulsants If drug blood level is low, dosage may be increased; if it is high, dosage must be reduced -Often happens in children because they are growing or having a growth spurt

Describe the onset of action.

When the concentration of a drug at the site of action is sufficient to start a physiologic (pharmacologic) response When the drugs starts making a physiologic response NOT when you take the medication

Describe a capsule.

You cannot break apart a capsule; if you're going to give the whole capsule, you may be able to but the powder substance in apple sauce or pudding, etc.

A nurse can administer oral drugs with ---- to help with absorption.

a full glass of water

What is being described below? •Drug is transferred from entry site into the body's circulating fluids •Rate depends on route, blood flow, and solubility of the drug •Medications can be lipid soluble or water soluble •Subcutaneous and intramuscular injection absorption is affected by circulation •Intravenous medications are absorbed fastest •Topical medications applied to the skin can be influenced by skin thickness and hydration (An older adult whose skin is super dry is not as permeable as a newborn babies skin)

absorption

Drugs with complete attachment and response are called ----.

agonists

Drugs that attach but do not elicit a response are called -----.

antagonists

What does excretion rely on?

GI tract and kidneys

Which route of administration has the fastest rate of distribution? a)Subcutaneous b)Intramuscular c)Transcutaneous d)Intravenous

D

Descrive an enteric-coated.

DO NOT crush them

Describe changes in excretion.

Drug interactions that cause a change in excretion usually act in the kidney tubules by changing the pH to enhance or inhibit excretion Classic example of altered urine pH is the combination of acetazolamide and quinidine

Describe changes in metabolism.

Drug interactions usually result from a change in metabolism that involves inhibiting or inducing the enzymes that metabolize a drug Serum drug levels usually increase a result of inhibited metabolism when drugs are given concurrently Common drugs that bind to enzymes and increase the metabolism of other drugs are phenobarbital, carbamazepine, rifampin, and phenytoin

What are partial agonists?

Drugs that interact with a receptor to stimulate a response but inhibit other responses- work well on some receptor sites but they block other receptor sites Important because they give you pain relief but they don't cause as many side effects as agonist drugs

Describe a suppository.

Educate your patient to unwrap the suppository; can apply lubricant to facilitate insertion

Describe the duration of action.

How long the drug has a pharmacologic affect Once the medication is no longer giving an type of effect is when the duration of action is present

What are the 5 drug stages after administration?

LADME 1. liberation 2. absorption 3. distribution 4. metabolism 5. excretion

Describe changes in distribution.

Many interactions that cause a change in distribution usually affect the binding of a drug to an inactive site Unbound drugs -The ones that are doing the job Drugs are "bound" to proteins in the blood during transportation - Not going to be able to do anything The more a drug is bound to a protein, the less available it is to the circulation Some medications can cause binding or unbinding of another medication, increasing or decreasing its effect

Describe changes in absorption.

Most drug interactions that alter absorption take place in the GI tract Antacids increase the gastric pH and can inhibit the dissolution of ketoconazole tablets Many alterations in absorption can be managed by separating the times of administration

What are allergic reactions?

Occur among patients who have previously been exposed to a drug and whose immune systems have developed antibodies to the drug Normally doesn't't happen after the first dose but after the second dose these are present because of the antibodies that have formed Allergic reactions occur because of a previous exposure to an antigen (the drug) that results in the development of antibodies against the drug

What are idiosyncratic reactions?

Occur when something unusual/abnormal happens when drug is first administered

Describe a transdermal patch.

Remove the old patch prior to placing the next one Make sure it is in a clean dry place Date and initial the new patch

Describe drug interactions.

Said to occur when the action of one drug is altered or changed by the action of another drug

Describe half-life of drugs.

The amount of time required for 50% of the drug to be eliminated from the body Factors modifying the quantity of drug reaching a site of action after a single oral dose Drugs with long half-lives (digoxin is 36 hours) need to be administered once daily.

Describe the first-pass effect.

The metabolism of a drug and its passage from the liver into the circulation A drug given via the oral route may be extensively metabolized by the liver before reaching the systemic circulation (high first-pass effect) The same drug—given IV—bypasses the liver, preventing the first-pass effect from taking place, and more drug reaches the circulation

Describe the peak action.

The time at which the drug reaches the highest concentrations on the target receptor sites, thereby inducing the maximal pharmacologic response for the dose given Time at which the drug reaches the highest concentrations on the target receptor sites As good as the medication is going to get

Describe the enteral route of drug administration.

Via the gastrointestinal tract by the oral, rectal, or nasogastric routes Make sure the nasogastric tube is in place prior to giving medications Takes 30 minutes to about an hour to expect any therapeutic response You must have a working gut for enteral medications to work; check bowel sounds

Drugs that attach and elicit a small response but also block other responses are called ----.

partial agonists