Drugs and Behavior/Characteristics/Absorption

How many poppy seed bagels would need to be consumed in order to obtain a positive screen for opiates?

100

Confirmatory testing of positive drug screens is important because the screening methods that are used are wrong what percentage of the time and why?

25-35% of the time because legal drugs show up on the tests as well.

Through oral administration, approximately what % of a drug is absorbed within the first 2-3 hours?

75%

Sublingually

A drug that is placed under the tongue

Transdermally

A drug that passes through the skin

Therapeutic Index

A measure of a drug's safety in medical care, and is computed as the ratio ED 50/LD 50

In terms of pharmacokinetics, what works together to determine bioavailability?

Absorption and distribution

What is the correct sequence of a drug elimination and breakdown?

Blood-hepatic artery-liver-metabolized to by products-returned to bloodstream-kidney

Mainlining

Common street term for injecting a drug intravenously.

Injection

Delivery of a drug by a needle directly into the blood stream, muscle, or right under the skin.

True or false: The first-pass effect refers to drug metabolism in the liver?

False

True or false: The transdermal route of administration is an effective one for most drugs?

False

True or false: amphetamines have an antagonistic effect on those of alcohol, reducing alcohol's impairment of motor skills?

False

True or false: drugs administered intranasally should be water-soluble rather than fat soluble because of the high water content in the nasal cavity?

False

True or false: drugs that are more soluble in lipids are less readily absorbed than other drugs?

False

True or false: one advantage of inhaling drugs is that large amounts of the drug can be absorbed in one administration?

False

True or false: recent research has indicated that environmental differences don't seem to play a role in the pharmacokinetics of drug metabolism?

False

True or false: the sublingual route of drug administration is slower and less efficient than oral administration?

False

The effect of a drug depends most fundamentally on what?

How much drug is taken.

Where does first pass metabolism take place?

In the liver and gastrointestinal tract.

Subcutaneous Injection

Injecting the drug right under the layers of the skin, easiest routs to use, this route may be preferred medically for drugs that are not irritating to body tissue because of the route's relatively slow constant absorption rate, should not be taken this way whent he drug irritates body tissue and when large volumes of solution must be taken to introduce enough of the drug to achieve the desired effect.

Intravenous

Injection into the veins, common street name is mainlining, effects can be immediate, doses can be precisely adjusted according to the person's response, highly associated with complications because large quantities of the drug quickly reach the site of action.

Disadvantages of Inhalation

Possible to absorb only small amount of a drug by inhalation in one administration

What form of administration is suppository method?

Rectal

Slope

Reflects the amount of latitude there is in a drug dose before a stronger effect is reached.

Advantages to inhalation

Results in rapid and effective absorption can get from the lung to the brain in 8 seconds.

Mucus Membrane (Intranasal)

Snorting cocaine powder, chewing tobacco, taken through the nose, then absorbed through the mucous membranes of the nose and the sinus cavities, snorting or sniffing.

Oral administration

Swallowing, in the form of pills, capsules, powders, or liquids, when it is swallowed, the drugs pass through the stomach and are absorbed primarily through the small intestine.

Drug potency

Term referring to the minimum dose of a drug that yields its efficacy

Biotransformation

Term used to describe the modification of certain chemicals before the pass through the body

Half-life

The amount of time that must pass for the amount of drug in the body to be reduced by half.

Pharmacokinetics

The branch of pharmacology that concerns the absorption, distribution, biotransformation, and excretion of drugs.

Blood brain barrier

The capillaries leading into the brain are not very porus, so many molecules can's get through.

Potentiation

The combined effects of multiple drugs is greater than the sum of the parts.

Biphasic drug effect

The effect of a drug may go in one direction, say increase as the dose goes up, but then the effect changes direction, decreases, as the dose continues to increase.

What does the bioavailability of a drug tell us?

The effects

Rebound effects

The elimination of a drug from the body often is associated with changes that are opposite to those that were caused by the drug.

On a dose-effect curve, the drug potency is?

The minimum dose of a drug that yields its efficacy.

Bioavailability

The portion of the original drug dose that reaches its site of action or that reaches a fluid in the body that gives the drug access to its site of action.

Metabolism

The process by which the body breaks down matter into more simple components and waste.

Absorption

The rate and extent to which a drug leaves its site of administration.

Zero-order kinetics

The rate at which a drug is metabolized is independent of its concentration in the blood.

First-Order Kinetics

The rate of elimination is dependent on the amount of drug in the body.

Pharmacodynamics

The study of the biochemical and physiological effects of drugs and their mechanisms of action.

Transdermal administration

Through and across the skin, allows the level of the drug to remain constant in the blood, bandage like device, resivoir of the drug is released slowly and continually through he membrane

True or false: Studies have shown that different ethic groups may show differences in responsiveness to certain prescription drugs?

True

True or false: When a drug is fat soluble, sniffing is a rapid and effective way to absorb it?

True

True or false: marijuana is an example of a drug with affinity for fatty tissue which allows it to register in the blood for some time?

True

True or false: metabolites of some drugs cause unwanted side effects while those of other drugs cause desired psychoactive effects?

True

True or false: the amount of time that marijuana can be detected in the body depends upon whether use is acute or chronic?

True

True or false: the effects of alcohol and barbituates are synergistic and combing the two has led to many accidental deaths?

True

True or false: valium is an example of a drug that can easily pass through the blood brain barrier because it is highly fat soluble?

True

Rectal administration

Used when you are vomiting or taking cancer medication, or if you are unconscious and unable to swallow

Dissolved

When a drug changes from solid to liquid after being mixed with a liquid.

Feedback

When in a series of events, what happens in a later event alters those preceding it.

What conditions lead to more rapid drug-absorption?

When there is more blood flow at the site of absorption.

Sublingual administration

a drug tablet is placed under the tongue and dissolved in saliva, absorbed through the mouth's mucous membranes.

An example of a drug that is metabolized according to Zero-order Kinetics?

alcohol

What drug has no set of elimination because its metabolites are used too efficiently in the body to be measured reliably?

alcohol

To become deactivated a drug must do what?

be excreted unchanged from the body and be chemically changed.

Advantages of rectal administration

bioavailability is 50% higher compared to orally

What affects drug distribution?

blood flow, fat solubility of the drug, and diffusibility of membranes.

A drug's dose is computed according to a person's what?

body weight.

What are common sites for intramuscular drug injection?

butt, deltoid, and thigh

Disadvantages of transdermal administration

causes irritation, hard to adjust the dosage to be specific to what you want

Commonly sniffed drugs

cocaine, heroin, tobacco

Speed-balling

combination of heroin and cocaine

What does the presence of food do to absorption and the maximum drug level achieved for orally administered drugs?

delays and decreases.

What are the ways drugs are excreted from the body?

directly in the feces, in liver bile, in mother's milk, through lungs, in sweat

Factors that effect absorption

drugs that are more soluble in lipids, the form in which the drugs administered, circulation at the site of absorption, the size of the absorbing surface

In a prototypic dose-effect curve. the vertical axis refers to what, and the horizontal axis refers to what?

effect size, and range of drug dose

is half-life related to first-order kinetics or zero order kinetics?

first-order kinetics

What fruit can interact with multiple types of drugs?

grape fruit

Advantages to transdermal administration

has to be potent to be soluble in oil and water, get through membrane of the patch and skin, kind of drug you would take over a long period of time

What regions of the body get major portions of the drug shortly after absorption?

heart, brain, kidney

What factors affect distribution?

how much blood a region gets, diffusibility, fat solubility, where the drug selectively binds to elements of the body

What is the quickest route of administration to use in order to obtain the effect of a drug?

inhalation

Intramuscular injection

injection within the muscle, requires deeper penetration than the subcutaneous method, associated with faster absorption rate when the drug is prepared in a water solution and there is a good rate of blood flow at the site of administration, most common sites are butt, deltoid, and thigh, can result in localized pain, and the risk of infection from irritating drugs and tissue damage is high.

Disadvantages of Intranasal

irritation of the location, membrane itself, biggest danger of snorting cocaine overtime causes nose bleeds, and destruction of nasal septum.

What is the most important organ for excretion of drugs and their metabolites?

kidney

Enzymes in what parts of the body are important in the metabolization of drugs?

kidneys, liver, and gastrointestinal tract

Once in the bloodstream, orally-administered drugs pass through what before reaching the brain?

liver

What drug can be detected in the system for up to 1 month following chronic use?

marijuana

Drugs that are more or less soluble in lipids penetrate body membranes and therefore reach sites of action more easily?

more

The more diffusible tissues receive the drug more or less rapidly?

more

Selective binding or affinity

more a drug binds with certain elements in the body, the more likely it is to remain in the blood stream

Medication administered sublingually

nitroglycerin

What is a method used to administer barbituates?

oral, rectal, subcutaneous, intramuscular

Advantages to Intranasal

rapid, faster than oral

Advantages of sublingual administration

results in faster and more efficient drug absorption than oral, preferred to oral administration for drugs that irritate the stomach and cause vomiting.

Inhalation

second most popular, inhaled and then absorbed through the lung's membranes, method for gas exchange

Disadvantages of oral administration

slow, occasional vomiting, stomach distress, unpredictable absorption rate, and stomach acid destroys some drugs

Advantages to oral administration

slow, safer, easier to give measured amounts of a specific dose.

When drugs are swallowed, they pass through the stomach and are absorbed in what?

small intestines.

Which method of drug injection is preferred medically for drugs that are irritating to body tissue?

subcutaneous

Which route is easiest of the drug injection routes to use?

subcutaneous

Which route of administration is preferable to oral administration for drugs that irritate the stomach and cause vomiting?

sublingual

Disadvantages of rectal administration

unpleasant, can cause irritation

How long can alcohol be detected in the system by using a drug test?

up to 1 day

Disadvantages of sublingual administration

used less frequently than might be expected because of the unpleasant taste of many of the drugs that me be taken this way.