Pharmacology - Chapter 1, 2, 3, 4 & 5

Pharmacokinetics discusses how a drug is:

1) Absorbed (taken into the body) 2) Distributed (moved into various tissues) 3) Metabolized "biotransformation" (changed into a form that can be excreted) 4) Excreted (removed from the body) Pharmacokinetics is also concerned with a drug's: 1) onset of action 2) peak concentration level 3) duration of action

The actual concentration that a drug reaches in the body results from a dynamic equilibrium involving several processes: What are these processes?

1) Absorption from the site of entry 2) Distribution to the active site 3) Biotransformation (metabolism) in the liver 4) Excretion from the body

List four types of allergic responses to drug therapy:

1) Anaphylactic reaction 2) Cytotoxic reaction 3) Serum sickness reaction 4) Delayed allergic reaction

For a drug to be approved for marketing a drug must pass through?

1) Animal testing 2) Testing on healthy humans 3) Selected testing on people w/ the disease being tx 4) Broad testing on people w/ the disease being tx

Drug-drug interactions can occur in the following situations:

1) At the site of absorption: One drug prevents or accelerates absorption of the other drug. 2) During distribution: One drug competes for the protein-binding site of another drug, so the second drug cannot be transported to the reactive tissue. 3) During biotransformation: One drug stimulates or blocks the metabolism of the other drug. 4) During excretion: One drug competes for excretion with the other drug, leading to accumulation and toxic effects of one of the drugs. 5) At the site of action: One drug may be an antagonist of the other drug or may cause effects that oppose those of the other drug, leading to no therapeutic effect.

Although OTC drugs have been found to be safe when taken as directed, what are some of the problems associated w/ OTC drug use?

1) OTCs could mask the S&S of disease, making Dx difficult 2) Taking OTCs with prescription meds could result in drug interactions & interfere w/ drug therapy 3) Not taking OTCs as directed could result in serious overdoses 4) Some OTC drugs were not rigorously screened & tested by the current drug evaluation protocols b/c they were developed & marketed before the current laws were put into effect. 5) Many pts. do not consider OTC drugs to be medications & therefore do not report their use.

Drug-drug interactions are important considerations in clinical practice. When evaluating a patient for potential drug-drug interactions, what would the nurse expect to address?

1) The need to adjust drug dose or timing of administration. 2) Increased adverse effects 3) The use of herbal or alternative therapies

Pharmacokinetics is also concerned with a drug's:

1) onset of action 2) peak concentration level 3) duration of action

Pharmacokinetic considerations include:

1) onset of drug action (how long it will take to see the beginning of the therapeutic effect) 2) drug half-life 3) timing of the peak effect (how long it will take to see the maximum effect of the drug) 4) duration of drug effects (how long the patient will experience the drug effects) 5) metabolism or (biotransformation) of the drug 6) site of excretion

What are 7 possible drug reactions to tissue and organs?

1) rash/hives 2) stomatitis 3) superinfection 4) sensory effects 5) blood dyscrasia 6) glucose levels 7) electrolyte imbalance

What factors are taken into consideration when determining the half-life of a drug?

1) the absorption rate 2) the distribution to the tissues 3) the speed of biotransformation 4) how fast a drug is excreted

The half-life of a drug is determined by what 4 pharmacokinetic processes?

1) the balance of absorption 2) distribution 3) metabolism 4) excretion

Why is it important as a nurse to understand the basic principles of pharmacokinetics and pharmacodynamics?

1) to anticipate therapeutic and adverse drug effects 2) to intervene in ways that ensure the most effective drug regimen for the pt

Name the major side effect categories of drugs:

1. dermatological 2. stomatitis (mucus membrane) inflammation/damage 3. superinfections (from destruction of normal flora) 4. blood dyscrasia - bone marrow suppression 5. toxicity 6. renal impairment 7. hyper/hypoglycemia 8. electrolyte imbalances 9. sensory/auditory damage 10. CNS damage 11. teratogenicity

What is an antagonist?

A drug has an affinity for a receptor but displays little or no intrinsic activity, therefore preventing a response from occurring.

Brand name drugs are?

A name given to a drug by the pharmaceutical company that developed it Brand Names or trade names are protected by copyright. The symbol ® after a trade name indicates that the name is registered by and restricted to the drug manufacturer.

Drug-Laboratory test interactions occur by?

Admin. of a particular drug may alter results of tests that are done on various chemical levels or reactions as part of a diagnostic study--> keep this in mind as a nurse--> if one test result is altered & does not fit in with the clinical picture or other test results, consider the possibility of a drug-laboratory test interference.

What is an agonists?

Agonist interacts directly with receptor sites to cause the same activity that natural chemicals would cause at that site.

Agonist

An agonist drug has an attraction, or affinity, for a receptor and stimulates it. The drug then binds with the receptor to produce its effect.

Is the generic or brand name usually capitalized in drugs?

Brand names are usually capitalized while generic names are not.

Why can Generic Drugs be produced more cheaply?

Companies producing them do not have the research, advertising, or quality control that the pharmaceutical companies have

What is a competitive agonist?

Competes with the agonist for receptor sites. B/c this type of drug binds reversibly to the receptor site, administering large doses of an agonist can overcome the antagonist's effects.

SOme oif

Drugs may work by replacing a missing body chemical, by stimulating or depressing cellular activity, or by interfering with the functioning of foreign cells.

Generic or nonproprietary drugs are?

Drugs no longer protected by a patent and can be produced by companies other than the ones that developed it. *many states require that a drug be dispensed in the generic form if one is available.

What is pharmacodynamics?

How the drug affects the body

Half-life

In pharmacokinetics, the time required for half of an administered dose of a drug to be eliminated by the body, or the time it takes for the blood level of a drug to be reduced by 50%. Important to determine when steady state is reached

What are the risks with generic drugs?

In the past, some quality-control problems were found with generic products.

What are the benefits of generic drugs?

Keep down the cost of drugs & health care in the US

Why is knowing the half-life of the drug important as a nurse?

Knowing the half-life of a drug helps in predicting dosing schedules and duration of effects.

What are some of the benefits of OTC drugs?

Making the drugs more easily accessible and much less expensive to consumers. Some examples include GI medications (such as ranitidine and cimetidine) and antihistamines (such as loratadine).

prescription drugs

Medicines that cannot be used without the written approval of a licensed physician

Over-the-counter (OTC) drugs:

Over-the-counter drugs are drugs that are available w/o a prescription for self-treatment of a variety of complaints. OTCs are deemed to be safe when used as directed. Some OTC drugs were not rigorously screened and tested by the current drug evaluation protocols because they were developed and marketed before the current laws were put into effect. Many of these drugs were "grandfathered" into use because they had been used for so long. The FDA is currently testing the effectiveness of many of these products and, in time, will evaluate all of them.

Outline and describe the steps involved in developing and approving a new drug in the US.

Preclinical trials - involve testing of potential drugs on laboratory animals to determine their therapeutic and adverse effects. Phase I - test on healthy human subjects Phase II - test on pts. who have the disease Phase III - test in clinical settings to determine any unanticipated effects or lack of effectiveness FDA evaluates drug - b/4 it can be marketed-- which relies on committees of experts familiar w/ the specialty area of drug Phase IV- continued evaluation = prescribers must report to the FDA any untoward or unexpected adverse effects associated with drugs they are using, and the FDA continually evaluates this info

What are the 5 schedules of controlled substances? (w/ examples)

Schedule I (C-I): High abuse potential and no accepted medical use (heroin, marijuana, LSD) Schedule II (C-II): High abuse potential with severe dependence liability (narcotics, amphetamines, and barbiturates) Schedule III (C-III): Less abuse potential than schedule II drugs and moderate dependence liability (non-barbiturate sedatives, non-amphetamine stimulants, limited amounts of certain narcotics) Schedule IV (C-IV): Less abuse potential than schedule III and limited dependence liability (some sedatives, anti-anxiety agents, and non-narcotic analgesics) Schedule V (C-V): Limited abuse potential. Primarily small amounts of narcotics (codeine) used as antitussives or antidiarrheals.

T or F? All drugs have effects other than the desired therapeutic effect?

TRUE

T or F ? A patient cannot be allergic to a drug that has never been taken, although patients can have cross-allergies to drugs within the same drug class as one formerly taken?

TRUE? Drug allergies only occur after a patient develops antibodies to a drug after exposure to the drug.???? (double check answer)

Describe the federal controls on drugs that have abuse potential.

The Controlled Substance Act of 1970: established categories for ranking of the abuse potential of various drugs The DEA (Drug Enforcement Agency) enforces their control.

The amount of a drug that is needed to cause a therapeutic effect is?

The critical concentration; If a drug is going to work properly on these reactive tissues, and thereby have a therapeutic effect, it must attain a sufficiently high concentration in the body.

Drug-food interaction occurs when?

The drug and the food are in direct contact in the stomach. FOR EXAMPLE: The antibiotic tetracycline cannot be taken w/ iron products. Tetracycline also binds with calcium to some extent & should not be taken w/ foods or other drugs containing calcium.

On average, how long does it take to develop and approve a drug in the US?

The entire drug development and approval process can take 5 to 6 years in the US. (p 10.)

Pharmacology

The study of the biological effects of chemicals. Pharmacology is the scientific study of the origin, nature, chemistry, effects, and uses of drugs.

What is the half-life of a drug?

The time it takes for the amount of drug in the body to decrease to one half of the peak level it previously achieved.

Anaphylactic reaction:

This allergy involves an antibody that reacts with specific sites in the body to cause the release of chemicals, including histamine, that produce immediate reactions (mucous membrane swelling and constricting bronchi) that can lead to respiratory distress and even respiratory arrest.

Cytotoxic reaction:

This allergy involves antibodies that circulate in the blood and attack antigens (the drug) on cell sites, causing death of that cell. ***this reaction is not immediate but may be seen over a few days.

Serum Sickness Reaction:

This allergy involves antibodies that circulate in the blood and cause damage to various tissues by depositing in blood vessels. **This reaction may occur up to 1 wk or more after exposure to the drug.

Delayed Allergic Reaction:

This reaction occurs several hours after exposure and involves antibodies that are bound to specific white blood cells

Discuss five common examples of drug-induced tissue damage:

Tissue damage can include: 1) Skin problems - rashes, hives 2) Mucous membrane inflammation - stomatitis 3) Blood dyscrasias - bone marrow suppression caused by drug effects 4) Superinfections - infections caused by organisms that are usually controlled by the normal flora 5) liver or renal toxicity

Brand name drugs are also known as?

Trade, proprietary, and innovator name --> given by the company that developed it

What factors affects the body's response to drugs?

Weight Age Gender Physiological factors—diurnal rhythm, electrolyte balance, acid-base balance, hydration Pathological factors—disease, hepatic dysfunction, renal dysfunction, gastrointestinal dysfunction, vascular disorders, low blood pressure Genetic factors Immunological factors—allergy Psychological factors—placebo effect, health beliefs, compliance Environmental factors—temperature, light, noise Drug tolerance Cumulation effects Interactions

What is an adrenergic agonist?

a drug that stimulates the adrenergic receptors of the sympathetic nervous system, either directly (by reacting with receptor sites) or indirectly (by increasing norepinephrine levels)

When considering the pharmacokinetics of a drug, what points would the nurse need to consider?

a) How the drug will be absorbed d) How the drug will be excreted e) How the drug will be metabolized f) The half-life of the drug

Poisoning

occurs when an overdose of a drug damages multiple body systems, leading to the potential for fatal reactions

Before receiving final FDA approval to be marketed to the public, drugs must pass through several stages of development. These include what? Explain these steps.

preclinical trials: initial trial of a chemical thought to have therapeutic potential; uses laboratory animals, not human subjects phase I study: a pilot study of a potential drug using a small number of selected, usually healthy human volunteers phase II study: a clinical study of a proposed drug by selected physicians using actual patients who have the disorder the drug is designed to treat; patients must provide informed consent phase III study: use of a proposed drug on a wide scale in the clinical setting with patients who have the disease the drug is thought to treat phase IV study: continuous evaluation of a drug after it has been released for marketing

Adverse drug effects can be one of several types:

primary actions, secondary actions, and hypersensitivity reactions

What is an adverse drug reaction?

undesired effects that may be unpleasant or even dangerous The drug may have other effects on the body besides the therapeutic effect. The patient may be sensitive to the drug being given. The drug's action on the body may cause other responses that are undesirable or unpleasant. The patient may be taking too much or too little of the drug, leading to adverse effects.

What is pharmacokinetics?

what the body does to the drug (absorption, distribution, metabolism, excretion)